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What is different in operative dentistry?

What is different in operative dentistry?

Tex Dent J. 2010 Mar;127(3):271-8

Authors: Overton JD

There have been both large and small changes in operative dentistry in the last 30 years. Extension for prevention is no longer the mantra. The design features of amalgam preparations have moved into the smallest preparations possible to gain full access to the carious dentin. The default Class 2 amalgam or resin composite is a slot preparation with no preparation of the occlusal fissures. Class 1 fissure caries once implied the entire fissure system was to be cut out. Now only the known carious portions of the fissure are cut away, the tooth is restored, and the remaining fissures in that tooth are sealed. Resin composite preparations have no depth requirements and saucer shaped boxes are more favorable for lowering shrinkage strains on the bonded walls. Re-mineralization of proximal lesions that can be seen on a radiograph is now a proven successful service for many lesions that are at or just into the dentin by radiographic interpretation. The largest paradigm shift has been in the decision that in vital teeth with normal pulps soft dentin can be left over a vital asymptomatic pulp with every expectation that the direct restoration will be successful long term.

PMID: 20391946 [PubMed - indexed for MEDLINE]




Real-time measurement of dentinal fluid flow during amalgam and composite restoration.

Real-time measurement of dentinal fluid flow during amalgam and composite restoration.

J Dent. 2010 Apr;38(4):343-51

Authors: Kim SY, Ferracane J, Kim HY, Lee IB

This study examined changes in the dentinal fluid flow (DFF) during restorative procedures and compared permeability after restoration among restorative materials and adhesives.

PMID: 20060432 [PubMed - indexed for MEDLINE]




Effect of magnetic resonance imaging on microleakage of amalgam restorations: an in vitro study.

Effect of magnetic resonance imaging on microleakage of amalgam restorations: an in vitro study.

Dentomaxillofac Radiol. 2009 Oct;38(7):470-4

Authors: Shahidi SH, Bronoosh P, Alavi AA, Zamiri B, Sadeghi AR, Bagheri MH, Javadpour S

The technique of MRI, using powerful magnets, plays an important role in the diagnosis of diseases of the head and neck without any ionizing radiation. Because of the potential hazard imposed by the presence of ferromagnetic metals, patients with implanted metallic objects are excluded from MRI. However, amalgam restorations seem to be safe. The purpose of this study was to evaluate microleakage of amalgam restorations following MRI.

PMID: 19767518 [PubMed - indexed for MEDLINE]




Selection of dental materials and longevity of replaced restorations in Public Dental Health clinics in northern Sweden.

Selection of dental materials and longevity of replaced restorations in Public Dental Health clinics in northern Sweden.

J Dent. 2009 Sep;37(9):673-8

Authors: Sunnegċrdh-Grönberg K, van Dijken JW, Funegċrd U, Lindberg A, Nilsson M

To investigate the selection of direct restorative materials and longevity of replaced restorations in relation to operator and patients characteristics.

PMID: 19477572 [PubMed - indexed for MEDLINE]




Longevity of conventional and bonded (sealed) amalgam restorations in a private general dental practice.

Longevity of conventional and bonded (sealed) amalgam restorations in a private general dental practice.

Br Dent J. 2009 Jan 24;206(2):E3; discussion 88-9

Authors: Bonsor SJ, Chadwick RG

To compare and contrast the longevity of conventionally placed dental amalgam restorations with those placed using bonding techniques.

PMID: 19148188 [PubMed - indexed for MEDLINE]




Influence of thermal stress on marginal integrity of restorative materials.

Influence of thermal stress on marginal integrity of restorative materials.

J Appl Oral Sci. 2008 Mar-Apr;16(2):106-10

Authors: Cenci MS, Pereira-Cenci T, Donassollo TA, Sommer L, Strapasson A, Demarco FF

The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC); glass ionomer (GI) or amalgam (AM), and randomly assigned to 18 groups (n=20) according to the material, number of cycles (500 or 1,000 cycles) and dwell time (30 s or 60 s). Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h), sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: thermal cycling regimens increased leakage in all AM restorations (p<0.05) and its effect on RC and GI restorations was only significant when a 60-s dwell time was used (p<0.05). Marginal integrity was more affected in AM restorations under thermal cycling stress, whereas RC and GI ionomer restoration margins were only significantly affected only under longer dwell times.

PMID: 19089200 [PubMed - indexed for MEDLINE]




Factors influencing dentists' choice of amalgam and tooth-colored restorative materials for Class II preparations in younger patients.

Factors influencing dentists' choice of amalgam and tooth-colored restorative materials for Class II preparations in younger patients.

Acta Odontol Scand. 2009;67(2):74-9

Authors: Vidnes-Kopperud S, Tveit AB, Gaarden T, Sandvik L, Espelid I

To identify factors associated with dentists' decisions on choice of restorative material in children and adolescents.

PMID: 19085213 [PubMed - indexed for MEDLINE]




[Amalgam, composites and compomers: a comparative histologic study of periodontal tissues (Part 2)].

[Amalgam, composites and compomers: a comparative histologic study of periodontal tissues (Part 2)].

Rev Belge Med Dent. 2008;63(1):36-44

Authors: Zogheib CM, Mokbel N, Naaman NB

Violation of the biologic width could induce different periodontal consequences depending on many factors such as the type of the restorative material used. In this study, the histological performance and the marginal adaptation of three filling materials (amalgam, composite resin and compomer) are evaluated after a period of three months. Class V cavities with apical margin located at the alveolar bone crest were prepared on Pointer dogs teeth and restored with these three materials. Histological analysis showed that lesions in epithelial attachment were mainly noticed with amalgam fillings and the scale of inflammatory cells was the highest when amalgam was used. Compomer showed the best marginal adaptation.

PMID: 18754538 [PubMed - indexed for MEDLINE]




Fracture resistance of amalgam/glass-polyalkenoate open sandwich Class II restorations: an in vitro study.

Fracture resistance of amalgam/glass-polyalkenoate open sandwich Class II restorations: an in vitro study.

J Dent. 2008 Nov;36(11):873-7

Authors: Roberts HW, Vandewalle KS, Charlton DG, Berzins DW

To investigate the effect of two glass-polyalkenoate restorative materials used as root-dentin replacements on the fracture strength of Class II amalgam restorations.

PMID: 18692947 [PubMed - indexed for MEDLINE]




Clinical performance of Class II adhesive restorations in pulpectomized primary molars: 12-month results.

Clinical performance of Class II adhesive restorations in pulpectomized primary molars: 12-month results.

J Dent Child (Chic). 2008 Jan-Apr;75(1):33-43

Authors: Zulfikaroglu BT, Atac AS, Cehreli ZC

The purpose of this report was to present the 12-month results of a prospective, randomized study evaluating the clinical and radiographic success rates of Class II adhesive restorations in pulpectomized primary molars. A total of 75 restorations were placed over root canal-treated primary molars, filled with a calcium hydroxide paste. The restorative systems tested were: (1) group 1: amalgam (negative control); (2) group 2: a hybrid resin composite (TPH, Dentsply) with prior acid conditioning and bonding with an etch-and-rinse adhesive (Prime&Bond NT, Dentsply); (3) group 3: a polyacid-modified resin composite (Dyract, Dentsply) bonded with Prime&Bond NT; (4) group 4: Dyract with prior nonrinse conditioner (NRC) treatment and bonding with Prime&Bond NT; and (5) group 5: a polyacid-modified resin composite (F2000) in conjunction with a self-etch adhesive (Prompt-L-Pop, 3M/ESPE). The restorations were evaluated clinically using the modified USPHS/Ryge criteria at 1, 2, 3, 4, 5, 6, 9, and 12 months. Radiographic evaluations were made in accordance with predetermined criteria. During the evaluation period, 12 teeth (group1=4, group2=1, group3=4, group4=3, and group5=2) were extracted due to radiographic evidence of failure. There was no difference between groups regarding the clinical evaluation criteria (P>.05) except marginal discoloration at 9 and 12 months (P<.05). The overall success rate at 12 months was 81% (group 1=73%, group 2=93%, group 3=73%, group 4=80%, and group 5=87%). Teeth restored with the resin composite+total-etch/bonding (group 2), followed by those with F2000+self-etch adhesive (group 5) exhibited the highest clinical and radiographic success rates. Radiographic failures observed beneath failed restorations were strongly suggestive of coronal microleakage.

PMID: 18505646 [PubMed - indexed for MEDLINE]




Effect of thickness of cavity wall on fracture strength of pulpotomized primary molar teeth with class capital PE, Cyrillic amalgam restorations.

Effect of thickness of cavity wall on fracture strength of pulpotomized primary molar teeth with class capital PE, Cyrillic amalgam restorations.

Eur Arch Paediatr Dent. 2008 Mar;9(1):31-6

Authors: Mazhari F, Gharaghahi M

This was to evaluate the effect of different thicknesses of cavity walls on fracture strength of pulpotomized primary molar teeth with class II amalgam restorations.

PMID: 18328236 [PubMed - indexed for MEDLINE]




Effect of different adhesive protocols vs calcium hydroxide on primary tooth pulp with different remaining dentin thicknesses:24-month results.

Effect of different adhesive protocols vs calcium hydroxide on primary tooth pulp with different remaining dentin thicknesses:24-month results.

Clin Oral Investig. 2008 Mar;12(1):91-6

Authors: Büyükgüral B, Cehreli ZC

The aim of this randomized, controlled, single-blind and prospective study was to evaluate the clinical and radiographic success rates of three different bonding protocols vs calcium hydroxide liner for protection of the dentin-pulp complex of primary molars with different remaining dentin thicknesses. Two hundred forty primary molar teeth with moderate to deep occlusal caries were restored in 97 children who met inclusion criteria. After cavity preparation, the teeth were randomly assigned into four groups (n = 60/group) with respect to the material used for protection of the dentin-pulp complex: (1) total-etching with 36% phosphoric acid followed by an acetone-based adhesive (Prime&Bond NT), (2) a self-etch adhesive system (Xeno III), (3) an acetone-based adhesive (Prime&Bond NT) without prior acid conditioning, and (4) control: calcium hydroxide cement (Dycal). Teeth in groups 1-3 were restored with a polyacid-modified resin-based composite (Dyract AP) and those in group 4 with amalgam. The remaining dentin thickness was calculated using image analysis software (ImageJ). The teeth were evaluated clinically and radiographically for 24 months. The distribution of restored teeth with minimal remaining dentin thickness (< or =0.5 mm) was 3.3, 8.3, 8.3, and 10% for groups 1, 2, 3, and 4, respectively. Despite the absence of pulpal protection in groups 1-3, none of those teeth exhibited any significant clinical or radiographic symptom during the study period. After 2 years, the clinical and radiographic success rate of restorative treatments was 100%. Protection of the dentin-pulp complex with the tested bonding protocols resulted in similar outcomes in mainly shallow and medium deep cavities as compared to calcium hydroxide amalgam in more deep cavities, when indirect pulp treatment was performed in class I compomer restorations.

PMID: 17896116 [PubMed - indexed for MEDLINE]




Microleakage of different amalgams bonded with dual cure resin cements.

Microleakage of different amalgams bonded with dual cure resin cements.

SADJ. 2007 Mar;62(2):056, 058-61

Authors: Lombard R, du Preez IC, Oberholzer TG

To reduce microleakage in high-copper amalgam restorations, bonding of amalgam was introduced.

PMID: 17624174 [PubMed - indexed for MEDLINE]




Durability of amalgam in the restoration of class II cavities in primary molars: a systematic review of the literature.

Durability of amalgam in the restoration of class II cavities in primary molars: a systematic review of the literature.

Eur Arch Paediatr Dent. 2007 Mar;8(1):5-13

Authors: Kilpatrick NM, Neumann A

To review the available literature on the durability of amalgam when used to restore interproximal (class II) cavities in primary molars.

PMID: 17394885 [PubMed - indexed for MEDLINE]




Comparison of proximal contacts of Class II resin composite restorations in vitro.

Comparison of proximal contacts of Class II resin composite restorations in vitro.

Oper Dent. 2006 Nov-Dec;31(6):688-93

Authors: Loomans BA, Opdam NJ, Roeters FJ, Bronkhorst EM, Burgersdijk RC

This study investigated the tightness of the proximal contact when placing posterior resin composite restorations with circumferential and sectional matrix systems in an in vitro model using a special measuring device (Tooth Pressure Meter). A manikin model was used with an artificial first molar in which an MO-preparation was ground, simulating the clinical situation of an amalgam replacement. This preparation was duplicated, resulting in 160 identically prepared teeth. These teeth were divided into 8 groups (n=20). In 2 groups, circumferential matrix bands (flat or contoured) in a Tofflemire retainer were applied. In the remaining 6 groups, 3 different separation rings were combined with 2 types of sectional matrix bands. All the cavities were restored using Clearfil Photo Bond and Clearfil AP-X. The tightness of the proximal contact was measured using the Tooth Pressure Meter. Data were statistically analyzed using SPSS 12. ANOVA was used to find differences in proximal contact tightness between the groups. Tukey tests were used to find differences between the homogeneous subgroups. The use of sectional matrices combined with separation rings resulted in tighter proximal contacts compared to when circumferential systems were used (p<0.001). The use of these devices is therefore recommended when posterior resin composite restorations are placed.

PMID: 17153978 [PubMed - indexed for MEDLINE]




[Microleakage of four different amalgam binding systems].

[Microleakage of four different amalgam binding systems].

SADJ. 2001 Feb;56(2):64-70

Authors: Oberholzer TG, Grobler SR, Rossouw RJ, van Wyk Kotze TJ, Grobler-Rabie A

This-study was undertaken to evaluate and compare microleakage in class V cavities in human teeth which were lined with Amalgambond Plus with HPA (Parkell, USA), Optibond Solo (Kerr, U.S.A.), Fuji Plus (GC Corporation, Japan) and Prime & Bond 2.1 (Dentsply, Switzerland), and then restored with Logic amalgam (SDI Australia). The restored teeth were thermocycled in basic fuchsin dye, sectioned, and evaluated for dye penetration. The interdiffusion zones were viewed in a confocal laser scanning microscope (CLSM). The results showed that no bonding system could totally eliminate microleakage. Statistical analysis revealed significant differences between Amalgambond Plus with HPA and Prime & Bond 2.1, Fuji Plus as well as Optibond Solo, for both the enamel and dentine sides. No significant differences were found between Prime & Bond 2.1, Fuji Plus and Optibond Solo, for both the enamel and dentine sides. Amalgambond Plus showed significantly more leakage at dentine sides while Prime & Bond 2.1 showed significantly more leakage at enamel sides. The CLSM revealed hybrid layers of different thicknesses, resin penetration into tubules, as well as resin incorporation within the spherical particles of the amalgam. Optibond Solo, Fuji Plus and Prime & Bond 2.1 can serve to improve the marginal seal of amalgam restorations.

PMID: 16894691 [PubMed - indexed for MEDLINE]




Reactionary dentinogenesis after applying restorative materials and bioactive dentin matrix molecules as liners in deep cavities prepared in nonhuman primate teeth.

Reactionary dentinogenesis after applying restorative materials and bioactive dentin matrix molecules as liners in deep cavities prepared in nonhuman primate teeth.

J Oral Rehabil. 2006 Jun;33(6):452-61

Authors: Duque C, Hebling J, Smith AJ, Giro EM, Oliveira MF, de Souza Costa CA

The aim of this in vivo study was to evaluate the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide hard-setting cement and EDTA-soluble preparation of dentine matrix proteins (ESDP) in deep cavities prepared in non-human primate teeth.

PMID: 16671993 [PubMed - indexed for MEDLINE]




Amalgam matrix for class II and class V preparations connected at the proximal box.

Amalgam matrix for class II and class V preparations connected at the proximal box.

J Am Dent Assoc. 2006 Feb;137(2):186-9

Authors: Mamoun JS, Ahmed MK

The authors present a technique for placing and reinforcing an amalgam matrix around combined Class II and Class V preparations that connect at the proximal box.

PMID: 16521384 [PubMed - indexed for MEDLINE]




Restorative treatment on Class I and II restorations in primary molars: a survey of Brazilian dental schools.

Restorative treatment on Class I and II restorations in primary molars: a survey of Brazilian dental schools.

J Clin Pediatr Dent. 2005;30(2):175-8

Authors: Motisuki C, Lima LM, dos Santos-Pinto L, Guelmann M

A survey was sent to 70 Brazilian dental schools evaluating techniques and restorative materials being taught for Class I and II preparation in posterior primary teeth by Pediatric Dentistry courses. After a 54% response rate, marked teaching diversity was found among Brazilian dental schools. Amalgam continues to be taught, but a tendency of preference towards more esthetic-like materials was observed.

PMID: 16491976 [PubMed - indexed for MEDLINE]




Placement and replacement of restorations by selected practitioners.

Placement and replacement of restorations by selected practitioners.

Aust Dent J. 2005 Jun;50(2):81-9; quiz 127

Authors: Tyas MJ

There are few Australian data on the reasons for placement and replacement of restorations, and the extent to which these are carried out in general practice.

PMID: 16050086 [PubMed - indexed for MEDLINE]




Class I and Class II silver amalgam and resin composite posterior restorations: teaching approaches in Canadian faculties of dentistry.

Class I and Class II silver amalgam and resin composite posterior restorations: teaching approaches in Canadian faculties of dentistry.

J Can Dent Assoc. 2005 Jun;71(6):405-6

Authors: McComb D

A 10-question survey was mailed to the 10 Canadian faculties of dentistry to determine current approaches to teaching undergraduates about silver amalgam and resin composite for posterior restorations in adults and children. Responses were received from all 10 pedodontic programs and from 8 of the 10 operative and restorative programs. The use of silver amalgam and posterior composite for restorations of primary and permanent teeth is covered in the curricula of all dental schools, but the relative emphasis on the 2 materials varies. In the operative and restorative programs, curriculum time devoted to silver amalgam is either greater than or equal to that devoted to posterior composite. Five of the 8 schools reported greater educational emphasis on silver amalgam for the permanent dentition; however, course directors noted that the preference among patients seen in clinics is tending toward composite restorations. Curricula appear designed to educate students about the optimal use of both materials. Requirements for performance of restorations during training generally do not specify the type of material; these requirements range from 60 restorations to 250 surfaces. Five of the 8 schools conduct clinical competency tests with both materials. The responses from the pedodontic programs were more diverse. The proportion of curriculum time devoted to each type of material in these programs ranged from less than 25% to more than 75%. Five schools reported more emphasis on silver amalgam, 3 schools reported equal emphasis, and 2 schools reported more emphasis on posterior composite. No clinical requirements were specified in any of the undergraduate pedodontic programs. Within some of the faculties, there were differences between the operative and restorative program and the pedodontic program with respect to emphasis on different materials for the posterior dentition.

PMID: 15955263 [PubMed - indexed for MEDLINE]




Bonded amalgam restorations: microleakage and tensile bond strength evaluation.

Bonded amalgam restorations: microleakage and tensile bond strength evaluation.

Oper Dent. 2005 Mar-Apr;30(2):228-33

Authors: Muniz M, Quioca J, Dolci GS, Reis A, Loguercio AD

The objective of this study was to evaluate the tensile bond strength (BS) and microleakage (MI) of bonded amalgam restorations to dentin when an unfilled and a filled system are used under three application modes.

PMID: 15853109 [PubMed - indexed for MEDLINE]




The amalgam-free dental school.

The amalgam-free dental school.

J Dent. 2004 Jul;32(5):371-7

Authors: Roeters FJ, Opdam NJ, Loomans BA

To review the change in teaching of Restorative Dentistry at Nijmegen dental school over the period 1986 to the present.

PMID: 15193785 [PubMed - indexed for MEDLINE]




Assessment of morphological changes and permeability of apical dentin surfaces induced by Nd:Yag laser irradiation through retrograde cavity surfaces.

Assessment of morphological changes and permeability of apical dentin surfaces induced by Nd:Yag laser irradiation through retrograde cavity surfaces.

J Contemp Dent Pract. 2004 May 15;5(2):102-13

Authors: Arisu HD, Bala O, Alimzhanova G, Türköz E

The purpose of this in vitro study was to observe the morphological changes and apical dye penetration at apical dentin surfaces induced by Nd:YAG laser irradiation at different power settings with and without a laser initiator. Seventy five single rooted human maxillary anterior teeth were used. Following the establishment of the working lengths, the root canals were enlarged with step-back technique. The apex of each root was resected 3 mm perpendicular to its long axis. Standard Class I cavities of 2 mm depth and 2 mm width were prepared. The teeth were randomly divided into five groups with fifteen teeth in each. In Group 1, the retrograde cavity preparations were lased with Nd:YAG laser at 2 W and those in Group 2 preparations were lased with Nd:YAG laser at 3.2 W. In Group 3, the retrograde cavity surfaces were lased with Nd:YAG laser at 2 W following the application of India ink. Group 4 was lased with the same settings of Group 2 after an absorbent cotton point soaked with India ink was inserted into the cut dentinal surfaces and the inner walls of the apical preparations. Group 5 served as control. Five teeth from each group were examined using scanning electron microscopy (SEM). The amounts of smear layer, debris, and recrystalized dentin present were assessed and scored. Retrograde cavities of ten teeth from each group were filled with amalgam to examine apical dye penetration. The teeth were immersed in 2% basic fuscin and kept for 48 hours. Dye penetration was evaluated by stereomicroscope at a magnification of X10. The results showed the usage of India ink with Nd:YAG laser enhanced the amount of melting and recrystalization of dentin and the radiation and initiator increased the leakage.

PMID: 15150638 [PubMed - indexed for MEDLINE]




Resin composite reinforcement of undermined enamel.

Resin composite reinforcement of undermined enamel.

Oper Dent. 2004 Mar-Apr;29(2):234-7

Authors: Abu-Hanna AA, Mjör IA

Studies have suggested that fracture resistance of undermined enamel increases when supported by a layer of bonded composite. Composite to reinforce enamel must have a secure foundation in dentin and/or enamel that is supported by dentin to perform optimally. A restorative technique is presented using resin composite material to support and reinforce undermined enamel that lacks dentinal support in traditional amalgam restorations. This technique is intended to conserve unsupported enamel cavity walls and weakened cusps in extensive Class I and II preparations.

PMID: 15088737 [PubMed - indexed for MEDLINE]




Survival of glass ionomer restorations placed in primary molars using atraumatic restorative treatment (ART) and conventional cavity preparations: 2-year results.

Survival of glass ionomer restorations placed in primary molars using atraumatic restorative treatment (ART) and conventional cavity preparations: 2-year results.

Int Dent J. 2004 Feb;54(1):42-6

Authors: Yu C, Gao XJ, Deng DM, Yip HK, Smales RJ

To compare the survival of glass ionomer cement (GIC) restorations placed in a dental clinic setting using both the atraumatic restorative treatment (ART) approach with hand instruments, and conventional cavity preparation with rotary instruments.

PMID: 15005472 [PubMed - indexed for MEDLINE]




The leakage of Class II cavities restored with packable resin-based composites.

The leakage of Class II cavities restored with packable resin-based composites.

J Contemp Dent Pract. 2003 Nov 15;4(4):1-11

Authors: Bala O, Uçtasli MB, Unlü I

Recently, new resin-based composites, called "packable" or "condensable" resin composites, are being promoted as amalgam alternatives. The purpose of this study was to evaluate leakage in Class II cavities restored with the five packable resin-based composites. On 45 freshly extracted human molars, cavities were prepared following a standardized pattern in which the Class II cavity had a length of 3.0 mm, width of 2.0 mm, and depth of 1.5 mm occlusally. The proximal box had an axial depth of 1.5 mm and a buccolingual width of 4.0 mm. The cervical margin was located 1.0 mm below the cement enamel junction (CEJ). The teeth were randomly divided into five groups of 8 each. The cavity surface was conditioned with 36% phosphoric acid, rinsed, excess water removed, and a dental bonding adhesive (Prime&Bond NT) was used for all the cavities. The teeth were then restored according to the manufacturer's instructions: Group 1, Surefil; Group 2, Solitaire; Group 3, Alert; Group 4, Filtek P60; and Group 5, Prodigy Condensable. After the restorations were completed, the specimens were finished and polished with an aluminum-oxide-coated disc, thermocycled, stained, sectioned, and viewed under a stereomicroscope for leakage at occlusal/enamel and gingival/dentin margins. All test groups showed that leakage of gingival/dentin margins were greater when compared with leakage of occlusal/enamel margins. At the occlusal/enamel margins, there were no significant differences between the materials; however, at gingival/dentin margins, Filtek P60 and Prodigy Condensable demonstrated less leakage, while Solitaire demonstrated greater leakage.

PMID: 14625591 [PubMed - indexed for MEDLINE]




Microleakage of a single-bottle adhesive system with 3 restorative materials: in vitro study and clinical considerations.

Microleakage of a single-bottle adhesive system with 3 restorative materials: in vitro study and clinical considerations.

Compend Contin Educ Dent. 2003 Oct;24(10):755-8, 760, 763 passim; quiz 772

Authors: Baghdadi ZD

The purpose of this study is to evaluate whether differences in material composition between 3 restoratives (compomer, packable composite, and amalgam) affect microleakage in class II preparations. Class II cavity preparations were made in the mesial and distal surfaces of a noncarious human premolar with the gingival margins in dentin. Preparations were etched and rinsed, and a single-bottle adhesive agent (Prime & Bond NT) was applied. Preparations were restored with the following materials (n = 8 per group): Dyract AP, SureFil, and Dispersalloy. For Dyract AP total-bond restorations, a new nonrinse conditioner (NRC) was tested against a total-etch with 36% phosphoric acid. Specimens were coated with nail varnish, immersed in toluidine blue for 24 hours, and evaluated for dye penetration, after removal of the restorative material, using a 0-to-4 scale. Statistical analysis using analysis of variance revealed significantly higher leakage scores (P < .05) for the NRC-Dyract AP group when compared with all other groups. Dispersalloy had significantly lower scores compared with Dyract AP and SureFil, all with the total-etch bonding technique. No statistically significant difference was observed between the latter 2 groups. The inability of all 3 materials to create a perfect seal in vitro raises concerns about the ability of the adhesive system to provide completely sealed restorations in vivo. However, bonded amalgam restorations are more effective in reducing marginal microleakage, particularly at the dentinal margin.

PMID: 14603630 [PubMed - indexed for MEDLINE]




Assessing microleakage of different class V restorations after Er:YAG laser and bur preparation.

Assessing microleakage of different class V restorations after Er:YAG laser and bur preparation.

J Oral Rehabil. 2003 Oct;30(10):1008-14

Authors: Corona SA, Borsatto MC, Pecora JD, De SA Rocha RA, Ramos TS, Palma-Dibb RG

This study assessed in vitro marginal leakage of class V cavities prepared by turbine and Er:YAG laser and restored with different materials. Sixty cavities with enamel and dentine margins were prepared and assigned to six groups: I, II, III by turbine and IV, V, VI by Er:YAG laser. The following restorative systems were used: groups I and IV: Bond 1 + Alert; II and V: Fuji II LC; III and VI: SBMP + Dispersalloy. After finishing, specimens were thermocycled for 8 h and 45 min (500 cycles), isolated, immersed in a 0.2% Rhodamine B solution, sectioned oro-facially and analysed for leakage. The dye penetration means (%) were: occlusal I: 10.09 (+/- 21.28), II: 3.25 (+/- 10.27), III: 0, IV: 41.77 (+/- 42.48), V: 23.37 (+/- 33.79), VI: 12.66 (+/- 24.06); cervical I: 16.49 (+/- 26.67), II: 4.34 (+/- 13.71), III: 0, IV: 37.71 (+/- 30.47), V: 39.56 (+/- 43.35) and VI: 72.53 (+/- 37.79). The use of Er:YAG laser for cavity preparation yielded higher degree of marginal leakage, as compared with the use of conventional air-turbine. The enamel interface provided better marginal sealing, comparing with dentine/cementum margin. As to the cavity preparation device (i.e. laser or bur), the analysis of the results showed that bonded amalgam and Fuji II LC provided less infiltration, than Alert. On the other hand, for lased cavities, Alert provided the best results, similar to those of Fuji II LC and superior to those reached by bonded amalgam.

PMID: 12974861 [PubMed - indexed for MEDLINE]




Atraumatic restorative treatment (ART): a three-year clinical study in Malawi--comparison of conventional amalgam and ART restorations.

Atraumatic restorative treatment (ART): a three-year clinical study in Malawi--comparison of conventional amalgam and ART restorations.

J Public Health Dent. 2003;63(2):99-103

Authors: Kalf-Scholte SM, van Amerongen WE, Smith AJ, van Haastrecht HJ

This study compares the quality of class I restorations made with the atraumatic restorative treatment (ART) technique and conventional class I amalgam restorations.

PMID: 12816140 [PubMed - indexed for MEDLINE]




Effect of operators' skills on increase in cavity volume of restorations.

Effect of operators' skills on increase in cavity volume of restorations.

Quintessence Int. 2003 Jan;34(1):27-30

Authors: Dörter C, Yildiz E, Erdemir U

The purpose of this in vitro study was to evaluate the change in cavity volume after removal of amalgam and resin composite restorations, based on the dental skills of the operators.

PMID: 12674355 [PubMed - indexed for MEDLINE]




Remaining dentine thickness and human pulp responses.

Remaining dentine thickness and human pulp responses.

Int Endod J. 2003 Jan;36(1):33-43

Authors: Murray PE, Smith AJ, Windsor LJ, Mjör IA

To evaluate pulp responses as a function of remaining dentine thickness (RDT) of 98 class V cavity preparations in 49 teeth of 31 patients aged 10-16 years.

PMID: 12656512 [PubMed - indexed for MEDLINE]




Survival time of Class II molar restorations in relation to patient and dental health insurance costs for treatment.

Survival time of Class II molar restorations in relation to patient and dental health insurance costs for treatment.

Swed Dent J. 2002;26(2):59-66

Authors: Sjögren P, Halling A

The aim was to evaluate the median survival time (MST) of direct molar class II restorations (glass ionomer, composite, amalgam) in the Nordic countries and the initial cost, as well as, the theoretical cost per year of function of treatment for patients, Social Insurance Office (SI), and total cost, at Public Dental Services (PDS) in Sweden. Restoration longevity studies conducted in general practice settings in the Nordic countries were used to calculate the MSTs of class II restorations. The initial costs were based on fee schedules from all PDS in Sweden. The MSTs of class II molar restorations in Nordic general practices were shortest for glass ionomer and longest for amalgam. Glass ionomer molar class II restorations had the lowest and composite restorations had the highest initial total cost at PDS in Sweden. The highest theoretical cost per year of function was seen for composite restorations. Amalgam restorations seem to have the longest functional lifetime in Nordic general practices and the lowest theoretical cost per year of function for the patients at PDS in Sweden.

PMID: 12462873 [PubMed - indexed for MEDLINE]




Removal of amalgam, glass-ionomer cement and compomer restorations: changes in cavity dimensions and duration of the procedure.

Removal of amalgam, glass-ionomer cement and compomer restorations: changes in cavity dimensions and duration of the procedure.

Oper Dent. 2002 Nov-Dec;27(6):613-20

Authors: Szep S, Baum C, Alamouti C, Schmidt D, Gerhardt T, Heidemann D

This study investigated changes in the dimensions of Class II cavities following the removal of amalgam, glass ionomer and compomer restorations. In 30 extracted caries-free human molars, preparation for 60 mesio-occlusal and occluso-distal cavities (two cavities per tooth) occurred. With a CEREC 3 laser triangulation sensor and software-based construction analysis, the dimensions of the cavities at seven defined sites were measured. The cavities were randomized into four groups. Group 1 was restored with Ketac-Fil glass-ionomer cement, Group 2 with amalgam and Group 3 with Compoglass F compomer. In Group 4, Compoglass F was used in combination with photochromic Tetric Flow Chroma as a cavity liner. The completed restorations were then removed using 2x magnification and the cavities were once again controlled using the laser system. The duration of the removal procedure was also recorded. Changes in cavity dimensions (depth, height and width) following removal of the restorations were significantly smaller in Groups 1 and 2. Groups 3 and 4 were characterized by a significant overextension of the cavities compared to Groups 1 and 2 in all three dimensions. Group 4, with Tetric Flow Chroma as a cavity liner, showed better results than Group 3, but this improvement was not statistically significant. The duration of the removal procedure was significantly shorter in Group 2 than in the other groups.

PMID: 12413228 [PubMed - indexed for MEDLINE]




The use of amalgam in pediatric dentistry.

The use of amalgam in pediatric dentistry.

Pediatr Dent. 2002 Sep-Oct;24(5):448-55

Authors: Fuks AB

Amalgam has been widely utilized to restore posterior teeth in pediatric dentistry, and is still taught as the material of choice for Class I and Class II restorations in many dental schools in the United States and Canada. Results of clinical trials are difficult to compare due to their heterogenicity, mainly due to differences in caries risk, operator skills, study duration, or patients' age. Thus, the different studies report failure rates of amalgams ranging from 12% to over 70%. Treatment of caries should meet the needs of each particular patient, based on his/her caries risk. In general, for small occlusal lesions, a conservative preventive resin restoration, using composite or compomer in conjunction with sealant, would be more appropriate than the classic Class I amalgam preparation. For proximal lesions, amalgam would be indicated for 2-surface Class II preparations that do not extend beyond the line angles of primary teeth. This recommendation might not be appropriate for high-risk patients or for restoring first primary molars in children 4 years of age and younger where stainless steel crowns have demonstrated better longevity. Currently, amalgam demonstrates the best clinical success for Class II restorations that extend beyond the proximal line angles of permanent molars.

PMID: 12412959 [PubMed - indexed for MEDLINE]




Fracture resistance of premolars with bonded class II amalgams.

Fracture resistance of premolars with bonded class II amalgams.

Oper Dent. 2002 Jul-Aug;27(4):349-53

Authors: Dias de Souza GM, Pereira GD, Dias CT, Paulillo LA

This study evaluated the fracture resistance of maxillary premolars with MOD cavity preparation and simulated periodontal ligament. The teeth were restored with silver amalgam (G1), Scotchbond Multi-Purpose Plus and silver amalgam (G2) and Panavia F and silver amalgam (G3). After restorations were made, the specimens were stored at 37 degrees C for 24 hours at 100% humidity and submitted to the compression test in the Universal Testing Machine (Instron). The statistical analysis of the results (ANOVA and Tukey Test) revealed that the fracture resistance of group 2 (G2=105.720 kgF) was superior to those of groups 1 (G1=72.433 kgF) and 3 (G3=80.505 kgF) that did not differ between them.

PMID: 12120771 [PubMed - indexed for MEDLINE]




Bacterial microleakage and pulp inflammation associated with various restorative materials.

Bacterial microleakage and pulp inflammation associated with various restorative materials.

Dent Mater. 2002 Sep;18(6):470-8

Authors: Murray PE, Hafez AA, Smith AJ, Cox CF

Many restorative materials are claimed to be successful in preventing bacterial microleakage and minimizing pulp inflammation. However, information regarding the in vivo performance of materials in comparison with each other is limited. The aim of this study was to evaluate and compare the pulp response of nine restorative materials when placed in non-exposed monkey cavities.

PMID: 12098576 [PubMed - indexed for MEDLINE]




Microleakage and retention of bonded amalgam restorations.

Microleakage and retention of bonded amalgam restorations.

Am J Dent. 2000 Oct;13(5):245-50

Authors: Winkler MM, Moore BK, Rhodes B, Swartz M

To compare the microleakage and bond strength exhibited by two light-cured, filled dentin bonding agents, a resin cement, and cavity varnish.

PMID: 11764110 [PubMed - indexed for MEDLINE]




Handling characteristics of a palladium-free gallium-based alloy compared with a high copper dental amalgam in a simulated clinical trial.

Handling characteristics of a palladium-free gallium-based alloy compared with a high copper dental amalgam in a simulated clinical trial.

J Oral Rehabil. 2001 Nov;28(11):1029-36

Authors: Shaini FJ, Shortall AC, Ellakwa AE, Marquis PM

The aim of the current study was to compare the handling characteristics of a palladium-free gallium-based alloys (Galloy) with those of a high-copper amalgam (Permite C). The study had a particular interest in the evaluation of the direct placement delivery system used with both alloys. Ten dentists participated in the current study. Each placed two amalgam and two gallium-based alloy restorations in conventional class II cavities prepared in acrylic typodont teeth. None of the participating dentists had used the direct placement delivery system or had any previous experience with gallium-based alloy and no practice was allowed beforehand. The restorations were evaluated according to the following criteria: ease of loading the cavity (delivery system), ease of condensation, capacity to produce and sustain contact area, ease of carving, resistance to damage during removal of the matrix band, overall quality of the restoration and the available working time. Each criterion was given a score on a scale of 1-5 (1: very poor, 2: poor, 3: fair, 4: good, 5: very good). The results showed no statistically significant difference in the evaluated criteria between the two alloys (P > 0.05) except for criterion number 2 (ease of condensation, P=0.0005).

PMID: 11722719 [PubMed - indexed for MEDLINE]




Marginal adaptation of amalgam and resin composite restorations in Class II conservative preparations.

Marginal adaptation of amalgam and resin composite restorations in Class II conservative preparations.

Quintessence Int. 2001 May;32(5):391-5

Authors: Duncalf WV, Wilson NH

The purpose of this study was to compare and contrast the performance, in terms of marginal adaptation, of a non-gamma-2 amalgam alloy with a compact-filled light-cured composite in the restoration of Class II preparations of conservative design.

PMID: 11444073 [PubMed - indexed for MEDLINE]




[A retrospective in vivo study of Sonicsys approx restorations].

[A retrospective in vivo study of Sonicsys approx restorations].

Schweiz Monatsschr Zahnmed. 2001;111(2):152-8

Authors: Hugo B, Otto A, Stassinakis A, Hofmann N, Klaiber B

The purpose of this retrospective study was to determine the longevity and quality of Class II resin composite restorations with Sonicsys approx inserts placed in private practice. In 79 patients 213 composite restorations with margins in enamel and in dentin were evaluated clinically using a modified version of established USPHS-Criteria. The mean time in clinical service was 18+-8 months. The majority of the restorations investigated were rated as "good" (Alpha) or "clinically acceptable" (Bravo). In more than 90% sufficient proximal contact points were evaluated. Seven restorations had no contact to their adjacent tooth. Only one failed after an average period of 18 months in clinical service because of loss of the ceramic insert and was replaced. It is concluded that the composite restoration in combination with Sonicsys insert is an appropriate system for the restoration of Class II lesions in premolar and permanent molar teeth.

PMID: 11407330 [PubMed - indexed for MEDLINE]




Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorations.

Effect of cavity varnish, amalgam liner or dentin bonding agents on the marginal leakage of amalgam restorations.

J Oral Rehabil. 2001 May;28(5):492-6

Authors: Belli S, Unlü N, Ozer F

The purpose of this in vitro study was to compare marginal leakage of Class II amalgam restorations lined with different agents (two new generation dentin bonding systems, a cavity varnish and an amalgam liner). Forty freshly extracted human molar teeth were divided into five groups. Class II preparations were prepared in the mesial and distal surfaces of each molar. While the cavities in two groups were lined with two new generation bonding systems, the other two groups were treated with an amalgam lining material and a cavity varnish. Fifth group was used as control, without any lining. Amalgam* was hand-condensed into each preparation. Specimens were thermocycled, stained and sectioned. Microleakage was graded using a stereomicroscope. Mean microleakage scores for occlusal and cervical margins were calculated and analysed. For the leakage values on occlusal margins, Kruskal-Wallis test indicated no significant difference in all groups. For the leakage values on cervical margins, Kruskal-Wallis test indicated significant difference in four groups when compared with controls (P < 0.001). On the other hand, there was no significant difference between the occlusal and cervical leakage values in each group.

PMID: 11380791 [PubMed - indexed for MEDLINE]




Influence of different restorative techniques on microleakage in Class II cavities with gingival wall in cementum.

Influence of different restorative techniques on microleakage in Class II cavities with gingival wall in cementum.

Oper Dent. 2001 May-Jun;26(3):253-9

Authors: Demarco FF, Ramos OL, Mota CS, Formolo E, Justino LM

This study compared marginal leakage of Class II cavities with gingival margin in cementum using different techniques. Twenty-four recently extracted third molars were used. Proximal standard box cavities were prepared in both mesial and distal surfaces. The gingival margin was located apical to the cemento-enamel junction. All the preparations and restorations were performed by the same operator. Standard cavities were randomly divided into three groups (n = 16) and restored as follow: Group 1-light-cured composite resin; Group 2-self-cured composite resin + light-cured composite resin and Group 3-amalgam + light-cured composite resin. After polishing, the teeth were thermocycled and their gingival margins exposed to dye. Specimens were sectioned and leakage scores observed in accordance with a standard ranking. Data were subjected to statistical analysis (Kruskal-Wallis). Results showed that the amalgam/resin composite combination demonstrated the least leakage.

PMID: 11357567 [PubMed - indexed for MEDLINE]




Restorative pulpal and repair responses.

Restorative pulpal and repair responses.

J Am Dent Assoc. 2001 Apr;132(4):482-91

Authors: Murray PE, About I, Franquin JC, Remusat M, Smith AJ

Each year, about 90 million new restorations are placed in the United States and 200 million are replaced. Controversy surrounds the pulpal reactions and frequency of bacterial microleakage associated with common restorative materials. The authors investigated and compared pulpal reactions to different types of restorative materials.

PMID: 11315379 [PubMed - indexed for MEDLINE]




In vitro microleakage of luting cements and crown foundation material.

In vitro microleakage of luting cements and crown foundation material.

J Prosthet Dent. 2001 Mar;85(3):292-8

Authors: Lindquist TJ, Connolly J

Microleakage is a concern for the long-term prognosis of a cemented crown and foundation.

PMID: 11264938 [PubMed - indexed for MEDLINE]




Bacterial penetration of restored cavities.

Bacterial penetration of restored cavities.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001 Mar;91(3):353-8

Authors: Zivkovi? S, Bojovi? S, Pavlica D

The aim of this study was to assess the quality of the marginal seals of 7 restoratives by means of a bacterial penetration test in vitro. Sixty intact premolars and third molars that were scheduled for extraction were used in the test. There were 2 experimental groups of teeth, as follows: (1) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth. (2) A class V conventional cavity and a wedge erosion cavity were prepared on the buccal surface and the lingual surface, respectively, of each tooth with a completely removed enamel layer. The cavities were then reconstructed with different restorative materials. The quality of the marginal seals was evaluated by submerging the teeth in a bacterial suspension and incubating them in an anaerobic milieu at 37 degrees C for 20 hours. The teeth were subsequently processed for histologic data and bacterial staining. The best marginal sealing in both the wedge erosion and the class V cavities was provided by the Herculite/Optibond system and the Valux Plus/Scotchbond Multipurpose system. Bacterial penetration was slightly greater with the Luxat compomer and the Dyrect compomer, as well as with Vitremer glass ionomer cement and Fuji LC glass ionomer cement. The bacterial penetration test showed that the use of restorative material does not entirely eliminate microleakage.

PMID: 11250635 [PubMed - indexed for MEDLINE]




A comparison of the marginal and internal adaptation of amalgam and resin composite restorations in small to moderate-sized Class II preparations of conventional design.

A comparison of the marginal and internal adaptation of amalgam and resin composite restorations in small to moderate-sized Class II preparations of conventional design.

Quintessence Int. 2000 May;31(5):347-52

Authors: Duncalf WV, Wilson NH

The purpose of this study was to compare the marginal and internal adaptation of a non-gamma-2 amalgam and an ultrafine compact-filled light-cured composite in small to moderate-sized Class II restorations of conventional design.

PMID: 11203946 [PubMed - indexed for MEDLINE]




Evaluation of dental adhesive systems with amalgam and resin composite restorations: comparison of microleakage and bond strength results.

Evaluation of dental adhesive systems with amalgam and resin composite restorations: comparison of microleakage and bond strength results.

Oper Dent. 2000 Nov-Dec;25(6):512-9

Authors: Neme AL, Evans DB, Maxson BB

A variety of laboratory tests have been developed to assist in predicting the clinical performance of dental restorative materials. Additionally, more than one methodology is in use for many types of tests performed in vitro. This project assessed and compared results derived from two specific laboratory testing methods, one for bond strength and one for microleakage. Seven multi-purpose dental adhesives were tested with the two methodologies in both amalgam and resin composite restorations. Bond strength was determined with a punch-out method in sections of human molar dentin. Microleakage was analyzed with a digital imaging system (Image-Pro Plus, Version 1.3) to determine the extent of dye penetration in Class V preparations centered at the CEJ on both the buccal and lingual surfaces of human molar teeth. There were 32 treatment groups (n = 10); seven experimental (dental adhesives) and one control (copal varnish, 37% phosphoric acid) followed by restoration with either amalgam or resin composite. Specimens were thermocycled 500 times in 5 degrees and 55 degrees C water with a one-minute dwell time. Bond strength and microleakage values were determined for each group. ANOVA and Student-Newman-Keuls tests demonstrated an interaction between restorative material and adhesive system with a significant difference among adhesives (p < 0.05). Using a multi-purpose adhesive system resulted in both a statistically significant increase in bond strength and a statistically significant decrease in extent of microleakage (p < 0.05). The effect of the adhesive upon both microleakage and bond strength was greater in the resin composite restorations than in the amalgam restorations. Bond strength testing was more discriminating than microleakage evaluation in identifying differences among materials.

PMID: 11203864 [PubMed - indexed for MEDLINE]




Retentive strength of an amalgam bonding agent: chemical vs light vs dual curing.

Retentive strength of an amalgam bonding agent: chemical vs light vs dual curing.

Oper Dent. 2000 Nov-Dec;25(6):505-11

Authors: Winkler MM, Rhodes B, Moore BK

Dentin bonding agents have been shown to enhance retention of amalgam restorations by mechanical means. Little research is available on which mode of curing may optimize amalgam bonding. This in vitro study compared the bond strengths exhibited by three variations of a bonding agent, each using a different curing mode, with two earlier versions of amalgam resin liners and cavity varnish. The six test groups of lining agents for amalgam restorations included [C] chemical-cured, [L] light-cured and [D] dual-cured versions of one filled adhesive resin (Clearfil Liner Bond 2V), [LF] Light-cured, Filled resin (Clearfil Liner Bond 2, Kuraray Co.); [LCF] Light- and Chemical-cured, Filled resin Clearfil Liner Bond + Protect Liner, Kuraray Co) and [V] Varnish (Copalite, Cooley & Cooley, Ltd). For each group, 20 Class V cavity preparations were cut in human molars. The preparations were 2.5 mm deep and 3 mm wide at the pulpal floor, with a slightly divergent taper. After treating the preparation with the bonding agent, a 3/4 inch, 18 gauge flat-headed wire nail was seated in the cavity with its head at the pulpal floor of the preparation, and Tytin amalgam (Kerr Corp, Romulus, MI) was condensed into the preparation around the nail. All restorations were stored for 24 hours in distilled water at 37 degrees C, then subjected to 2500 thermal cycles (8 degrees C to 58 degrees C). After one week the samples were tested to failure in tension using an Instron Universal Testing Machine (crosshead speed = 2 mm/min) and peak load (kg) was recorded. Significant differences in retention were found using ANOVA and the Games & Howell post hoc test (p = 0.05). The mean loads at failure (+/- SD) were C 13.1 (+/- 2.4), L 21.8 (+/- 6.1), D 26.8 (+/- 7.4), LCF 23.8 (+/- 7.4), LF 21.4 (+/- 3.3) and V 2.0 (+/- 1.8). All dentin-bonding agents exhibited significantly greater retention than the varnish. While the bond strengths of the dual cured (D) and the light-cured (L) liners were not significantly different from one another, both were significantly higher than the chemically-cured (C) resin liner in terms of retention.

PMID: 11203863 [PubMed - indexed for MEDLINE]




Review of bonded amalgam restorations, and assessment in a general practice over five years.

Review of bonded amalgam restorations, and assessment in a general practice over five years.

Oper Dent. 2000 Sep-Oct;25(5):374-81

Authors: Smales RJ, Wetherell JD

This study reviewed the literature on bonded amalgam restorations and assessed the failure, marginal fracture and marginal staining behavior of 366 Permite C amalgam restorations lined with five dentin bonding resins (Scotchbond 2, Panavia Ex, Amalgambond, Amalgambond Plus, Geristore) and a polyamide cavity varnish (Barrier). The restorations were placed in the posterior permanent teeth of 190 adult patients and examined at intervals over periods of up to five years. There were five restoration failures (1.4%), usually from tooth fracture, involving Class II preparations in molar teeth. No instances of persistent pulpal sensitivity or recurrent caries were reported. The marginal deterioration of the restorations was assessed indirectly using photographs for comparison with two standard sets of enlarged color transparencies. Most of the marginal fracture and marginal staining scores were low, with little difference between the six lining materials at any period.

PMID: 11203845 [PubMed - indexed for MEDLINE]




Microleakage of bonded amalgam restorations: effect of thermal cycling.

Microleakage of bonded amalgam restorations: effect of thermal cycling.

Oper Dent. 2000 Jul-Aug;25(4):316-23

Authors: Helvatjoglou-Antoniades M, Theodoridou-Pahini S, Papadogiannis Y, Karezis A

This study examined the effect of thermal cycling on the microleakage of bonded amalgam restorations. Three dental amalgam alloys and a gallium alloy were tested with two adhesive resin systems and copal varnish as a control. Class V cavity preparations were prepared on 168 freshly extracted premolars or molars. The preparations were placed parallel to and 1.0 mm occlusal to the cementoenamel junction (CEJ). Four groups of 42 teeth each were treated with one of the following adhesive dentin systems: Bond-It, All-Bond 2/Resinomer or a copal varnish (Copalite). The four groups of 42 teeth each were then restored with one of three dental amalgams: Orosphere Plus, Indiloy, Oralloy or a Gallium alloy (Galloy), resulting in 12 test groups of 14 teeth each. The specimens were stored in double distilled water at 37 degrees C for 24 hours. Final contouring and polishing of the restorations were performed under water spray. Half of the restorations in each group were thermocycled for 3000 cycles (5 degrees C-37 degrees C-55 degrees C-37 degrees C) with a dwell time of 15 sec at each temperature. The other half were stored in double distilled water at 37 degrees C for 24 hours. Then all 168 restorations were stained with dye, sectioned and scored for microleakage. Results showed that the adhesive dentin systems reduced microleakage in amalgam restorations compared to copal varnish only in non-thermocycled specimens. Statistical analysis of the results showed that there was an extremely significant difference (p < 0.001) in microleakage between the non-thermocycled and the thermocycled specimens in all test groups, whereas, there was no significant difference (p > 0.05) among thermocycled specimens. The reduction of microleakage was not significantly different between Bond-It and All-Bond 2/Resinomer in non-thermocycled specimens. Oralloy showed the most microleakage in the non-thermocycled groups when compared to the other alloys using the same adhesive liner.

PMID: 11203837 [PubMed - indexed for MEDLINE]




A clinical and microbiological study of approximal carious lesions. Part 2: efficacy of caries removal following tunnel and class II cavity preparations.

A clinical and microbiological study of approximal carious lesions. Part 2: efficacy of caries removal following tunnel and class II cavity preparations.

Caries Res. 2001 Jan-Feb;35(1):8-11

Authors: Ratledge DK, Kidd EA, Beighton D

A randomized controlled clinical study was set up to assess caries removal following tunnel preparation (test group) and class II cavity preparation (control group). Sixty approximal lesions in adult posterior teeth, visible in the outer third of dentine on bite-wing radiographs, were referred for operative treatment. Initial dentine samples were taken on entry to the lesions in both groups. Following cavity preparation dentine samples were taken from beneath the marginal ridge in the tunnel group and at the cervical floor in both groups. Microbiological analysis was carried out to establish the level of infection of the dentine. The bacterial counts were high on entry to the lesions with a median log10 (CFU + 1) per sample of 3.07 (+/-1.24). Following cavity preparation bacterial counts at the cervical floor were significantly reduced in both amalgam and tunnel groups (p<0.00001). In the tunnel group, however, slightly increased bacterial counts were found beneath the marginal ridge compared to the cervical floor (p<0.01).

PMID: 11125190 [PubMed - indexed for MEDLINE]




Fracture resistance of Class II approximal slot restorations.

Fracture resistance of Class II approximal slot restorations.

J Prosthet Dent. 2000 Sep;84(3):297-302

Authors: Yaman SD, Yetmez M, Türköz E, Akkas N

Determination of the fracture resistance of various restorative materials in Class II approximal slot restorations has not been studied.

PMID: 11005902 [PubMed - indexed for MEDLINE]




Restorative treatment decisions on approximal caries in Norway.

Restorative treatment decisions on approximal caries in Norway.

Int Dent J. 1999 Jun;49(3):165-72

Authors: Tveit AB, Espelid I, Skodje F

A random sample of dentists in Norway were asked which radiographic criterion for assessing the initiation of restorative treatment of approximal caries they would use, and which type of cavity preparation and filling material they would prefer for a distal lesion on an upper second premolar. Only 19 per cent stated that they would treat approximal lesions confined to enamel, with 81 per cent opting to wait until lesions had reached dentine, compared with 66 per cent in a similar study performed in 1983. The tunnel preparation was cited most often as the preparation of choice (47.3 per cent), while 28.2 per cent preferred traditional class II preparations and 24.3 per cent a saucer shaped preparation. Only 15.5 per cent of the dentists chose amalgam as the restorative, 15.8 per cent composite, 22.3 per cent a conventional glass ionomer cement, 7.2 per cent a resin modified glass ionomer cement and 22.4 per cent a combination of glass ionomer and composite. There has been a shift in operative treatment criteria among the majority of dentists in Norway from 1983 to 1995, with most now waiting until the lesion is diagnosed in dentine radiographically before restoring. Most dentists prefer new preparation techniques for approximal caries using tooth coloured materials. Only every fifth dentist has amalgam as a first choice for approximal restorations in the posterior region.

PMID: 10858750 [PubMed - indexed for MEDLINE]




Microleakage of Class V restorations using two different compomer systems: an in vitro study.

Microleakage of Class V restorations using two different compomer systems: an in vitro study.

J Clin Dent. 1999;10(4):124-6

Authors: Estafan D, Pines MS, Erakin C, Fuerst PF

This study compared the marginal microleakage of Class V cavities restored with Dyract-AP and F2000. Forty Class V cavity preparations were performed on extracted human teeth. As a negative control, twenty teeth were used without Class V preparations. The apical foramina of the teeth were sealed with a layer of varnish and amalgam restorations. Class V cavity preparations with occlusal margins in enamel, and gingival margins in cementum or dentin that measured approximately three millimeters in width (gingival-occlusal) and length (mesial-distal), were prepared on the buccal surface of the teeth. Samples were divided randomly into 2 groups of 15, and restored per manufacturer's instructions using experimental primer/conditioner (PCC, D/C) and Single Bond Adhesive (3M). All restorations were polished with an abrasive finishing kit. After storage in 37 degrees C water for 24 hours, all specimens were thermocycled between 5 degrees C and 55 degrees C for 500 cycles with a 30-second dwell time, followed by immersion in 0.2% basic fucsine for 24 hours. Teeth were then embedded in cold cure acrylic resin, sectioned longitudinally, and the dye penetration at the enamel and cementum margins were scored at 30x magnification. Evaluations were rated from 0 to 3 (0 = no leakage; 1 = dye penetration up to one-half of the preparation depth; 2 = dye penetration more than one-half preparation depth, but less than the axial wall; 3 = dye penetration along the axial wall). Both F-2000 and Dyract-AP indicated no leakage in the enamel margins. Dyract-AP showed no leakage at either the enamel or dentin margins. Fisher's Exact Test revealed that this difference in dentin margins was statistically significant (p < 0.05). Under the given conditions, Dyract-AP and F-2000 demonstrated resistance to microleakage in enamel, and showed Dyract-AP to be more resistant to microleakage in dentin than F-2000.

PMID: 10825860 [PubMed - indexed for MEDLINE]




Amalgam restorations: postoperative sensitivity as a function of liner treatment and cavity depth.

Amalgam restorations: postoperative sensitivity as a function of liner treatment and cavity depth.

Oper Dent. 1999 Nov-Dec;24(6):377-83

Authors: Gordan VV, Mjör IA, Moorhead JE

The purpose of this clinical study was to assess the sensitivity reported by patients following the insertion of class 1 or class 2 amalgam restorations in the treatment of primary carious lesions of different depths. Ninety subjects with previously untreated teeth requiring restorations due to caries lesions were selected: 32 teeth had lesions that were clinically and radiographically judged to be located in the outer one-third of dentin, 30 were located in the middle one-third of dentin, and 28 were located in the inner one-third of dentin. Four different lining regimens were employed: Group 1--no linear; Group 2--two coats of Copalite liner; Group 3--a dentin adhesive resin liner (Scotchbond Multi-Purpose); Group 4--a resin-modified glass ionomer (Fuji Bond LC). Patients were contacted on days 2 and 7 postoperatively and questioned regarding the presence or absence of sensitivity, the stimuli that created the sensitivity, if any, the duration of any sensitivity, and the intensity of any sensitivity using a rating from None to Severe. If sensitivity was experienced on day 7, patients were also contacted on days 14, 30, and 90 to assess the sensitivity at those intervals. The chi-square test of independence showed no significance at the 0.05 level between the different dentin treatments and cavity depths. By day 2, 19% of lesions located in the outer one-third, 27% of lesions located in the middle one-third, and 29% of lesions located in the inner one-third of dentin were sensitive. On day 30, four teeth were still sensitive, two located in the middle one-third and two located in the outer one-third of dentin. On day 90 all teeth were without sensitivity.

PMID: 10823088 [PubMed - indexed for MEDLINE]




Preliminary study of the forces developed by practitioners during amalgam condensation.

Preliminary study of the forces developed by practitioners during amalgam condensation.

Int J Periodontics Restorative Dent. 1999 Aug;19(4):379-85

Authors: Blum JY, Micallef JP

The aim of this preliminary study was to analyze, in vitro, the forces developed by practitioners during amalgam condensation. Standardized Class II cavities were drilled into 40 freshly extracted teeth. The forces exerted during condensation were then measured by means of a new device, the Endographe, and plotted online or offline as a function of time on Endogrammes. The work techniques of the different practitioners revealed similarities. The mean values of the vertical forces (+/- SEM) were: 15 +/- 2 N for manual compaction of capsule amalgam; 8 +/- 3 N for manual compaction of amalgam with a higher mercury-to-alloy ratio; 6 +/- 4 N for mechanical compaction of encapsulated amalgam; and 4 +/- 2 N for mechanical compaction of the modified amalgam. For the horizontal components, the forces were, respectively, 5 +/- 2 N, 0.1 +/- 0.05 N, 3 +/- 1 N, and 0.7 +/- 0.2 N. The mean values of condensation time were 20 +/- 15 s for each incremental application, with a great variation in durations between the beginning and end of condensation. By visually depicting forces as a function of time, the Endographe can be used to analyze the process of amalgam insertion and condensation. Future research will study the relationship between the forces developed during condensation and the adaptation of the amalgam to the walls of the cavity.

PMID: 10709505 [PubMed - indexed for MEDLINE]




Debonding of adhesively restored deep Class II MOD restorations after functional loading.

Debonding of adhesively restored deep Class II MOD restorations after functional loading.

Am J Dent. 1999 Apr;12(2):84-8

Authors: Ausiello P, Davidson CL, Cascone P, DeGee AJ, Rengo S

To assess debonding due to functional loading at the cervical dentin margins of deep Class II MOD restorations prepared with a variety of adhesive restoratives in endodontically-treated teeth.

PMID: 10477988 [PubMed - indexed for MEDLINE]




Effect of topical fluoride application before and after amalgam restoration placement on recurrent caries inhibition.

Effect of topical fluoride application before and after amalgam restoration placement on recurrent caries inhibition.

Am J Dent. 1998 Aug;11(4):151-3

Authors: Donly KJ, Stufflebeam M, García-Godoy F

To evaluate the in vitro caries inhibition effects of 1.23% APF foam topical fluoride treatment of cavity preparations, prior to restoration placement and after restoration placement.

PMID: 10388367 [PubMed - indexed for MEDLINE]




Fracture strength of Class 2 amalgams with various cavity-lining materials.

Fracture strength of Class 2 amalgams with various cavity-lining materials.

Oper Dent. 1999 Jan-Feb;24(1):45-50

Authors: Palmer AE, Davis RD, Murchison DF, Cohen RB

This in vitro study compared the fracture resistance of class 2 amalgam restorations placed over seven materials: three resin-modified glass-ionomer cements (Fuji II LC, Vitrebond, and Vitremer), one polyacid-modified composite resin (VariGlass VLC), two conventional glass-ionomer cements (Ketac-Bond and GlasIonomer Cement), and one calcium-hydroxide material (Dycal). Eighty maxillary molars with flattened occlusal surfaces were divided into 14 experimental groups and two control (no liner) groups. One standardized class 2 amalgam cavity preparation was completed per tooth. Lining materials standardized at a thickness of 0.5 mm were placed in the approximal box portion of 10 test specimens per experimental group. Spherical amalgam was hand condensed into each cavity preparation. At 1 hour and again at 7 days, five samples from each group were fractured in compression using an Instron Universal Testing Machine. The force was directed at 10 degrees to the long axis of the tooth, 2.0 mm inside the approximal portion of the restoration. Results were analyzed using a two-way ANOVA for time and material. No statistically significant differences were found among the materials and controls at either time interval tested (P > 0.05). A statistically significant difference was found (P < 0.05) when comparing 1-hour and 7-day strengths. The 7-day specimens were more resistant to fracture than the 1-hour specimens. CONCLUSION: The fracture resistance of amalgam restorations was not affected by the presence of a material 0.5 mm thick placed in the approximal box when 3 mm of bulk of amalgam remained over it.

PMID: 10337298 [PubMed - indexed for MEDLINE]




Study of microleakage at Class I cavities prepared by Er:YAG laser using three types of restorative materials.

Study of microleakage at Class I cavities prepared by Er:YAG laser using three types of restorative materials.

J Clin Laser Med Surg. 1998 Dec;16(6):305-8

Authors: Khan MF, Yonaga K, Kimura Y, Funato A, Matsumoto K

The purpose of this in vitro study were to investigate microleakage at class I cavities filled with amalgam, composite resin, or glass-ionomer after preparation by Er:YAG laser and to compare the results with those by a conventional method using an air turbine.

PMID: 10204435 [PubMed - indexed for MEDLINE]




Bacterial counts in carious dentine under restorations: 2-year in vivo effects.

Bacterial counts in carious dentine under restorations: 2-year in vivo effects.

Caries Res. 1999;33(2):130-4

Authors: Weerheijm KL, Kreulen CM, de Soet JJ, Groen HJ, van Amerongen WE

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.

PMID: 9892780 [PubMed - indexed for MEDLINE]




Effect of tubule orientation in the cavity wall on the seal of dental filling materials: an in vitro study.

Effect of tubule orientation in the cavity wall on the seal of dental filling materials: an in vitro study.

Int Endod J. 1998 Sep;31(5):326-32

Authors: Wu MK, de Gee AJ, Wesselink PR

Dentinal tubules are oriented perpendicularly to the root canal walls but parallel to the lateral walls of class I occlusal preparation. It was hypothesized that the contact surface area of the material may depend on the tubule orientation in the cavity wall to which the material is applied, and that the difference in contact surface may affect the seal provided by the filling material. Standard central lumens, 2.6 mm in diameter and 3 mm high, were machined in human crown or root specimens. After removal of the smear layer with a conditioner, the specimens in each experimental group, consisting of 20 crown and 20 root specimens, were filled with amalgam, Fuji II glass ionomer (with or without varnish), or gutta-percha with Ketac-Endo root canal sealer. A modified fluid transport model was used to test the leakage along the fillings. Selected specimens were then split longitudinally and observed in a scanning electron microscope. The micrographs showed that all the test materials were pressed into the dentinal tubules. The contact surface of the material was calculated to be at least 45% larger in root specimens than in crown specimens, depending on the depth of the tubular penetration of the test material. The leakage results showed that all the test materials leaked less in root specimens than in crown specimens (P = 0.0000 for amalgam, P = 0.0374 for Fuji II with varnish, P = 0.0088 for Fuji II without varnish, P = 0.002 for gutta-percha with sealer). It was concluded that the tubule orientation in the cavity wall may influence the seal provided by certain dental filling materials.

PMID: 9823134 [PubMed - indexed for MEDLINE]




Clinical evaluation of two desensitizing agents for use under Class 5 silver amalgam restorations.

Clinical evaluation of two desensitizing agents for use under Class 5 silver amalgam restorations.

J Prosthet Dent. 1998 Sep;80(3):269-73

Authors: Schwartz RS, Conn LJ, Haveman CW

Postoperative sensitivity is sometimes reported to be a clinical problem after placement of silver amalgam restorations.

PMID: 9760358 [PubMed - indexed for MEDLINE]




Amalgam alternatives--micro-leakage evaluation of clinical procedures. Part I: direct composite/composite inlay/ceramic inlay.

Amalgam alternatives--micro-leakage evaluation of clinical procedures. Part I: direct composite/composite inlay/ceramic inlay.

J Oral Rehabil. 1998 Jun;25(6):443-7

Authors: Ziskind D, Avivi-Arber L, Haramati O, Hirschfeld Z

This study investigated the degree of dye penetration with three different types of tooth-coloured restorations. Twenty-four intact extracted molars were collected. The teeth were immediately stored in water at room temperature. Class II cavity preparations were prepared and restored with three different types of tooth-coloured restorations: A, composite resin in the incremental technique; B, composite inlay technique; and C, ceramic inlay. Specimens were subjected to 700 cycles of thermal stress. They were than immersed in 2% basic fuchsin dye. The teeth were sectioned in three planes before being ranked as to the amount of dye penetration. The highest score obtained on three plano-parallel sections was adopted as the representative value. The three groups were compared using the Kruskal Wallis non-parametric test. Dye penetration was significantly lower at the enamel margins when using the composite inlay system and the incremental technique compared to the ceramic inlay technique. The restorations placed using the composite inlay technique showed less dye penetration than the incremental technique at the dentine margins (P < 0.017).

PMID: 9687117 [PubMed - indexed for MEDLINE]




The effect of amalgam bonding on resistance form of Class II amalgam restorations.

The effect of amalgam bonding on resistance form of Class II amalgam restorations.

Quintessence Int. 1998 Feb;29(2):95-101

Authors: Della Bona A, Summitt JB

This study evaluated the load required to produce failure in Class II bonded amalgam restorations.

PMID: 9643242 [PubMed - indexed for MEDLINE]




The effect of cuspal flexure on a buccal Class V restoration: a finite element study.

The effect of cuspal flexure on a buccal Class V restoration: a finite element study.

J Dent. 1998 May;26(4):361-7

Authors: Rees JS, Jacobsen PH

Failure of Class V restorations is a clinical occurrence which is often blamed on inadequate moisture control. However, the effects of occlusal forces and cuspal movement may also have an effect. The aim of this study was to examine the effects that cuspal movement had on the shear forces around a buccal Class V restoration in a lower first premolar.

PMID: 9611942 [PubMed - indexed for MEDLINE]




Saucer-shaped cavity preparations for posterior approximal resin composite restorations: observations up to 10 years.

Saucer-shaped cavity preparations for posterior approximal resin composite restorations: observations up to 10 years.

Quintessence Int. 1998 Jan;29(1):5-11

Authors: Nordbĝ H, Leirskar J, von der Fehr FR

This clinical trial aimed at studying the long-term performance in routine clinical practice of saucer-shaped Class II resin composite restorations.

PMID: 9611469 [PubMed - indexed for MEDLINE]




The influence of modified cavity design and finishing techniques on the clinical performance of amalgam restorations: a 2-year clinical study.

The influence of modified cavity design and finishing techniques on the clinical performance of amalgam restorations: a 2-year clinical study.

J Oral Rehabil. 1998 Apr;25(4):269-78

Authors: Stratis S, Bryant RW

Use of modified cavo-surface angles (CSAs) and finishing techniques for amalgam restorations may influence the long term marginal fracture around these restorations. One operator placed 111 Tytin amalgam restorations in Class I and II preparations in the permanent teeth of 37 patients, each of whom received three restorations. One of these restorations was placed in a cavity prepared with a 'traditional' CSA and was finished more than 24 h after placement. Prepared cavities for the remaining two restorations for each patient were 'modified' with the aim of producing an occlusal CSA of 90-110 degrees. One restoration was carved-only and the other was finished more than 24 h after placement. Clinical evaluation of the restorations was carried out at baseline, 1 year and 2 years. At these times, the restorations were photographed and stone replicas were obtained from impressions taken at the cavity preparation stage to determine the cavo-surface angles. Careful application of the modified cavity design provided a mean cavo-surface angle of 109 degrees whereas a 'traditional' cavity design provided a mean cavo-surface angle of 126 degrees. Using the Mahler photographic method of evaluation, a combination of modification of the occlusal cavo-surface angle and finishing of the restoration was found to have an influence on the marginal fracture at 2 years. The clinical significance of these findings, with respect to the modified cavity design, is discussed.

PMID: 9610854 [PubMed - indexed for MEDLINE]




A new condensable composite for the restoration of posterior teeth.

A new condensable composite for the restoration of posterior teeth.

Dent Today. 1998 Feb;17(2):112-6

Authors: Leinfelder K, Prasad A

Undoubtedly the greatest resistance of clinicians to use composite resins in posterior teeth relates to technique sensitivity, time consumption, and complexity. Placing conventional posterior composite resins does not take into account that composites differ considerably from amalgam. This is particularly true with respect to its physical characteristics, especially insertion and packing properties. The development of a posterior composite resin that can be placed by an amalgam carrier and subsequently packed or condensed as an amalgam, should assist clinicians greatly in their ability to successfully restore class II cavity preparations. Acknowledgment is expressed to Bruce Small, DMD, for the clinical dentistry and slides.

PMID: 9560676 [PubMed - indexed for MEDLINE]




Dens evaginatus: review of the literature and report of several clinical cases.

Dens evaginatus: review of the literature and report of several clinical cases.

J Can Dent Assoc. 1998 Feb;64(2):104-6, 110-3

Authors: McCulloch KJ, Mills CM, Greenfeld RS, Coil JM

Dens evaginatus (DE) presents as an innocuous looking tubercle of enamel on the occlusal surface of a tooth, most commonly a bicuspid. Problems can arise when the tubercle is either worn, ground, or fractured off, resulting in pulpal exposure and possible loss of vitality of the tooth. Dentists who perform orthodontic treatment should be aware of this dental anomaly, which occurs in at least two per cent of the Asian and Native Indian populations. Bicuspid extraction cases should involve the extraction of the anomalous premolars rather than the normal ones. In addition, the dentist should be mindful of occlusal changes that may occur during treatment or occlusal equilibration, both of which can jeopardize the vitality of teeth with DE. Pulp capping or partial pulpotomy has been postulated to be one of the most reliable forms of vital tooth treatment when pulp exposure is encountered following the sterile removal of the tubercle. When pulp exposure is not encountered, preventive resin composite sealing of the dentin or class I amalgam cavity preparation seems to be the treatment of choice.

PMID: 9509817 [PubMed - indexed for MEDLINE]




Comparison of retentiveness of amalgam bonding agent types.

Comparison of retentiveness of amalgam bonding agent types.

Oper Dent. 1997 Sep-Oct;22(5):200-8

Authors: Winkler MM, Moore BK, Allen J, Rhodes B

Previous studies on amalgam bonded restorations indicated that amalgam bonding agents increased the bond strength of amalgam to tooth structure. This in vitro study was designed to compare how the mode of curing and the presence of filler in the resin would affect the bond strength of amalgam. The five test groups of lining agents for amalgam restorations included Chemical-cured, Unfilled resin (CU-Clearfil New Bond); Light-cured, Unfilled resin with a delayed chemical-cure property (LU*-Clearfil Photo Bond); Light-cured, Filled resin with a delayed chemical-cure property (LF*-Clearfil Photo Bond + Protect Liner); Dual-cured, Unfilled resin (DU-All-Bond 2); and Varnish (V-Copalite). For each group, 20 class 5 cavity preparations were cut on the facial, lingual, or proximal surfaces of human molars, which were embedded in acrylic resin. The preparations were 2.5 mm deep and 3 mm wide at the pulpal floor with a slightly divergent taper. After treating the preparation with the bonding agent, a 3/4-inch, 18-gauge flat-headed wire nail was placed into the cavity with the head at the pulpal floor of the preparation, and Tytin amalgam was then condensed into the preparation around the nail. The restorations were stored for 24 hours in distilled water at 37 degrees C and then subjected to 2500 thermal cycles (8 degrees C to 48 degrees C). After 1 week, specimens were tested to failure in tension using an Instron Universal Testing Machine (crosshead speed = 2 mm/min) and peak load (kg) was recorded. The mean loads at failure (+/- SD) were LF* 26.4 (+/- 7.0), DU 23.9 (+/- 6.4), LU* 16.0 (+/- 3.1), CU 14.3 (+/- 8.0), and V 9.5 (+/- 5.6). Significant differences were found using a one-way ANOVA and the Games and Howell post hoc test at a significance level of alpha = 0.05. The LF* and DU groups were not significantly different from each other, but they were significantly higher in peak load than all other groups. LU* was significantly higher than the varnish (V) but not significantly higher than CU. CU was not significantly higher than the varnish (V). The adhesives forming a thicker resin interface (the light-cured resin with filled resin liner and the dual-cured unfilled resin) demonstrated significantly greater retention than the light-cured unfilled resin, chemical-cured unfilled resin, and the varnish control.

PMID: 9484142 [PubMed - indexed for MEDLINE]




Effects of preparation designs and adhesive systems on retention of class II amalgam restorations.

Effects of preparation designs and adhesive systems on retention of class II amalgam restorations.

J Prosthet Dent. 1997 Sep;78(3):250-4

Authors: Görücü J, Tiritoglu M, Ozgünaltay G

This study evaluated the effects of three preparation designs and the influence of an adhesive system in Class II amalgam restorations when a load was applied directly to the marginal ridge.

PMID: 9297640 [PubMed - indexed for MEDLINE]




Longevity and cariostatic effects of everyday conventional glass-ionomer and amalgam restorations in primary teeth: three-year results.

Longevity and cariostatic effects of everyday conventional glass-ionomer and amalgam restorations in primary teeth: three-year results.

J Dent Res. 1997 Jul;76(7):1387-96

Authors: Qvist V, Laurberg L, Poulsen A, Teglers PT

The aim of this study was to compare the longevity and cariostatic effects of everyday conventional glass-ionomer and amalgam restorations in primary teeth. The materials consisted of 515 Ketac-Fil glass-ionomer restorations and 543 Dispersalloy amalgam restorations prepared in 666 children, from 3 to 13 years of age, by 14 dentists within the Danish Public Dental Health Service in the municipalities of Vaerlĝse and Hillerĝd. The restorations, of which 79% were of the Class II type, were in contact with 593 unrestored surfaces in adjacent primary and permanent teeth. After 3 years, 6% of the patients had dropped out of the study, and 33% of the teeth were exfoliated with the restoration in situ. A further 37% of the glass-ionomer and 18% of th amalgam restorations were recorded as failed (p < 0.001). The frequency of failures was highest for Class II glass-ionomer restorations, which showed a 50% median survival time of only 34 1/2 months, because of many fractures, while the 75% survival time for Class II amalgam restorations just exceeded the actual 36 months (p < 0.001). Caries progression was most often recorded in surfaces adjacent to amalgam restorations, and 21% of these surfaces needed restorative treatment vs. 12% of the surfaces adjacent to glass-ionomer restorations (p < 0.001). The three-year results indicated that conventional glass ionomer is not an appropriate alternative to amalgam for all types of restorations in primary teeth. In particular, the short longevity of Class II glass-ionomer restorations could not be compensated for by the reduced caries progression and need for restorative therapy of adjacent surfaces.

PMID: 9207772 [PubMed - indexed for MEDLINE]




Cavosurface margin geometry in conventional and air abrasion Class V cavity preparations.

Cavosurface margin geometry in conventional and air abrasion Class V cavity preparations.

Am J Dent. 1997 Apr;10(2):97-101

Authors: Boston DW, Alperstein KS, Boberick K

To compare cavosurface angle and area of missing tooth structure at the cavosurface margin in cross-sections of Class V cavity preparations made with a conventional carbide bur and with an air abrasive cavity preparation system.

PMID: 9545897 [PubMed - indexed for MEDLINE]




Marginal seal composition in amalgam restored teeth of varying marginal leakage.

Marginal seal composition in amalgam restored teeth of varying marginal leakage.

J Dent Assoc S Afr. 1997 Mar;52(3):157-64

Authors: Grossman ES, Witcomb MJ, Matejka JM

An in vitro study was performed to ascertain the marginal seal elemental composition of amalgam restored extracted teeth of known marginal leakage. Occlusal cavities were cut in 400 caries free extracted teeth and left unlined or lined with one of 5 bases. A varnish was applied to half the cavities followed by restoration with a low copper or high copper amalgam to produce 20 restoration combinations. The teeth were stored in 1 per cent NaCl and thymol for 3 and 12 months at 20 degrees C whereafter a standard fluorescent dye marginal leakage test was performed on 320 specimens (eight teeth per treatment). Restoration combinations were grouped into 4 seal classes depending on percentage marginal seal achieved for each combination: 0-25 per cent; 26-50 per cent; 51-75 per cent and 76-100 per cent. The 80 remaining teeth (2 teeth per treatment) were fractured to expose the restoration and cavity surface, covered with marginal seal material and this was analysed by energy dispersive X-ray analysis. Elemental seal composition was compared to percentage marginal seal achieved using ANOVA and Tukey's test with significance set at p < 0.05. Numbers of elemental analysis specimens falling into each marginal seal class was 0-25 per cent = 48; 26-50 per cent = 18; 51-75 per cent = 10; 76-100 per cent = 4. Of the 16 elements detected, nine were significantly linked to sealing/leakage: Ca, Cl, Cu, Mg, Hg, P, Ag, Sn and Zn. The findings have a bearing on the improved longevity of amalgam restorations.

PMID: 9461907 [PubMed - indexed for MEDLINE]




Teaching the use of bases and liners: a survey of North American dental schools.

Teaching the use of bases and liners: a survey of North American dental schools.

J Am Dent Assoc. 1996 Nov;127(11):1640-5

Authors: Weiner RS, Weiner LK, Kugel G

The authors surveyed 64 dental schools in North America about their instruction on the use of bases and liners. Respondents cited the materials being taught at the time of the survey, two years before the survey and four years before the survey. There was no consensus as to the materials being used. Copal varnishes and dentin bonding agents, or DBAs, were used most often in Class II preparations more than 2 millimeters from the pulp, and glass ionomers and DBAs were equally popular for Class II preparations within 1 mm of the pulp. Most schools were pleased with the materials they are currently teaching but continue to review material selection annually.

PMID: 8952241 [PubMed - indexed for MEDLINE]




Tunnel defects in dentin bridges: their formation following direct pulp capping.

Tunnel defects in dentin bridges: their formation following direct pulp capping.

Oper Dent. 1996 Jan-Feb;21(1):4-11

Authors: Cox CF, Sübay RK, Ostro E, Suzuki S, Suzuki SH

This study was conducted to observe the formation and nature of tunnel defects in dentin bridges, assess the nature of the associated soft tissue elements, and note the relationship of pulp inflammation and necrosis associated with these defects. A total of 235 teeth with class 5 cavity preparation exposures were randomly distributed throughout the dentitions of 14 adult rhesus monkeys. Each pulp was exposed and left open to the oral microflora at one of four time intervals, flushed with saline, debrided, capped with one of two hard-set calcium hydroxide medicaments [Ca(OH)2 (Dycal or Life)] and restored with a dispersed-phase amalgam alloy. Observation times were 14 days, 5 weeks, and 1 and 2 years. A total of 192 dentin bridges formed against the Ca(OH)2 medicaments Life or Dycal in 235 pulp-capped teeth. Considering all four capping periods, 89% of all dentin bridges contained tunnel defects (172 of 192). Forty-one percent (78) of the 192 dentin bridges were associated with recurring pulp inflammation or necrosis and were always associated with the presence of inflammatory cells and stained bacterial profiles. This study demonstrates that a statistically significant number of dentin bridges contain multiple tunnel defects, most of which appear to remain patent. These patent tunnels fail to provide a hermetic seal to the underlying pulp against recurring infection due to microleakage. Most Ca(OH)2 medicaments have been reported to disintegrate and wash out after 6 months, leaving a void underneath the restoration and thereby a pathway for bacterial infection. This study reemphasizes the need to employ biologically relevant measures that will provide a long-term clinical seal against microleakage following direct pulp capping with Ca(OH)2 medicaments alone.

PMID: 8957909 [PubMed - indexed for MEDLINE]




The use of a reinforced glass-ionomer cermet for the restoration of primary molars: a clinical trial.

The use of a reinforced glass-ionomer cermet for the restoration of primary molars: a clinical trial.

Br Dent J. 1995 Sep 9;179(5):175-9

Authors: Kilpatrick NM, Murray JJ, McCabe JF

The development of adhesive restorative materials has led to more conservative cavity design with greater reliance being placed upon the bond of a material with tooth tissue for retention of the restoration. Glass-ionomer cements may offer particular advantages but have yet to achieve the durability reported for amalgam. This study reports on the results of a 2.5-year prospective clinical trial comparing the durability of two glass-ionomer cements, a conventional material (Ketac Fil) and a metal reinforced cermet (Ketac Silver) in the restoration of Class II lesions in primary molars. Forty-six pairs of restorations were assessed in 37 children. The failure rate of Ketac Fil, 23%, was significantly lower than that of Ketac Silver, 41% (P < 0.05). The median survival time of the Ketac Fil restorations was significantly greater, 25.3 months, than that of the Ketac Silver restorations, 20.3 months (P < 0.05). These values may be an underestimate of the true longevity of both restoration types as many of the restorations survived intact at the censor date. Neither the age of the child nor the tooth restored influenced the durability of the restoration. The deterioration in both marginal integrity and anatomic form of the Ketac Silver restorations was significantly greater than the Ketac Fil restorations (P < 0.05). The durability of Ketac Silver was such that it cannot be recommended for use in restoring carious primary molars.

PMID: 7546970 [PubMed - indexed for MEDLINE]




Effect of surface treatment on marginal integrity of amalgam restorations (in vitro study).

Effect of surface treatment on marginal integrity of amalgam restorations (in vitro study).

Egypt Dent J. 1995 Jul;41(3):1313-20

Authors: Kamel FM

A total of 80 freshly extracted human molars, free from caries, cracks & decalcifications, were used in this study. Conservative class I cavities were prepared in the occlusal surface. Two types of amalgam alloys were used, high copper (Dispersalloy) & conventional (Velvalloy). The prepared cavities were classified into 5 groups, 16 each carve (C), carve & polish (CP), precarve burnish (BC), past-carve (CB) & pre post carve burnish (BCB). The specimens were thermally stressed using the stress fatigue device. The marginal integrity of the amalgam enamel interface were evaluated using SEM, for the four marginal quantities: 1--excellent margin, 2--open margins, 3--enamel fracture, and 4--amalgam fracture. The results of this study revealed that higher copper amalgam demonstrated superior marginal integrity than the conventional one. The pre-post carve burnish group showed the highest percentage of excellent margin than the other groups.

PMID: 9497675 [PubMed - indexed for MEDLINE]




Cariostatic and ultraconservative sealed restorations: nine-year results among children and adults.

Cariostatic and ultraconservative sealed restorations: nine-year results among children and adults.

ASDC J Dent Child. 1995 Mar-Apr;62(2):97-107

Authors: Mertz-Fairhurst EJ, Adair SM, Sams DR, Curtis JW, Ergle JW, Hawkins KI, Mackert JR, O'Dell NL, Richards EE, Rueggeberg F

The objective of this clinical study was to evaluate the long-term efficacy of placing sealed posterior composite restorations for arresting active caries. The tooth preparation for this bonded and sealed restoration was limited to placing a bevel in the enamel only, without the removal of the carious lesion. The radiographic and clinical performance of these ultraconservative sealed composite restorations placed over caries (CompS/C) was compared over a period of nine years with: 1) ultraconservative, localized sealed amalgam (AGS) restorations with no extension for prevention, and 2) traditional, unsealed amalgam restorations (AGU) with the usual extension for prevention outline form. Sealant retention with > 50 percent to 100 percent of the margins occurred in 64 percent of CompS/C and 82.5 percent of AGS restorations. After nine years the cumulative failure rates were 16 percent for CompS/C, 2.5 percent for AGS, and 17.1 percent for AGU restorations. Thus, the clinical performance of CompS/C restorations was slightly superior to that of the traditional AGU restorations. The AGS restorations were definitely superior to the traditional AGU restorations and to the CompS/C restorations in both children and adults alike. Complete sealant retention over CompS/C and AGS restorations was equivalent between children and adults (P = 0.14 and 0.74, respectively). A higher percentage of open margins in CompS/C restorations was seen, however, in children (17.4 percent) than adults (1.94 percent). This study has shown that Class I caries can be arrested by the CompS/C restoration.

PMID: 7608378 [PubMed - indexed for MEDLINE]




Amalgam restoration and in vitro caries formation.

Amalgam restoration and in vitro caries formation.

J Prosthet Dent. 1995 Feb;73(2):199-209

Authors: Grossman ES, Matejka JM

Black's class I classic cavity preparations were completed in 124 extracted intact human premolars, of which 120 were restored with one of two silver amalgams, five different base combinations, and with or without cavity varnish. This resulted in 20 different restoration combinations. The other four teeth remained unrestored. Aging for 3 months and 1 year in 1% NaC1 at 20 degrees C followed. After aging, 80 of the restored teeth and the four unrestored teeth were subjected to an in vitro bacterial challenge for 36 days. The other 40 specimens were placed in an acidified (pH 4.0) broth for the same length of time. Sections were prepared for polarized light microscopy, and outer wall and dentin carious lesions were measured. The results were evaluated with one-way ANOVA and Tukey's Student range test with a critical level of statistical significance of p < 0.05 and p < 0.005. Lesions produced by bacterial challenge were significantly smaller than those formed by acidified broth. Aging time and varnish did not significantly influence lesion size. Low copper amalgam, a calcium hydroxide paste base, and restoration per se significantly reduced lesion size. Reproducible measurement of wall lesion length was not possible. Secondary caries lesion size can be minimized by judicious selection of restoration material combinations.

PMID: 7722937 [PubMed - indexed for MEDLINE]




Lateral-access Class II restoration using resin-modified glass-ionomer or silver-cermet cement.

Lateral-access Class II restoration using resin-modified glass-ionomer or silver-cermet cement.

Quintessence Int. 1995 Feb;26(2):121-6

Authors: Croll TP

Direct-access preparation of a carious proximal surface is perhaps the most conservative approach to restoration. Physical properties and handling characteristics of silver amalgam and of resin composite and lack of fluoride ion release make these materials unsuitable for direct buccal- or lingual-access proximal restoration. Insufficient strengths and radiolucency of self-hardening glass-ionomer cements preclude their use for Class II restorations. However, glass-ionomer silver-cermet cement and some resin-modified glass-ionomer materials are proving useful for non-stress-bearing Class II restorations and may have applications in preventive dentistry. This article describes lateral-access Class II restoration with modified glass-ionomer cements. Emphasis is placed on careful handling of materials, maintenance of an ideal operative field, and conservation of tooth structure.

PMID: 7568722 [PubMed - indexed for MEDLINE]




Evaluation of new scoring systems for dye penetration for in vitro comparative microleakage studies.

Evaluation of new scoring systems for dye penetration for in vitro comparative microleakage studies.

Egypt Dent J. 1995 Jan;41(1):1049-56

Authors: Khalaf MA

This study was designed to evaluate one of the commonly used scoring systems--Score I--(categories from 0-5) to other two suggested scoring systems--Score II & III--(categories from 0-1 and 0-2 respectively), to test the degree of dye penetration for leakage studies. Class V cavities were prepared on 100 extracted human upper central incisors and filled with light cured composite. Herculite, and high copper amalgam. Tytin. All teeth were immersed in sodium fluorescein dye to test the degree of dye penetration. The results revealed that the suggested score II is very easy, simplified and representative but not indicative regarding the severity of dye penetration as score I. Score III are indicative and obvious discussion can be obtained rather than score I. For any leakage study the use of non parametric measurement is preferable than parametric ones.

PMID: 9497640 [PubMed - indexed for MEDLINE]




Increases in cavity volume associated with the removal of class 2 amalgam and composite restorations.

Increases in cavity volume associated with the removal of class 2 amalgam and composite restorations.

Oper Dent. 1995 Jan-Feb;20(1):2-6

Authors: Hunter AR, Treasure ET, Hunter AJ

Removal of amalgam restorations from class 2 cavities has been shown to cause increases in cavity volume. The aim of this study was to test whether the removal of composite resin from class 2 cavities was associated with greater increases in cavity volume compared to that produced during removal of amalgam. Class 2 cavities were prepared in previously extracted human molar teeth and the cavity volumes calculated. The teeth were restored with either amalgam or a composite resin and appropriate dentin bonding agent (APH/Optibond). Two dentists removed the restorations, and the resultant cavity volumes were calculated. The results were analyzed using a standard t-test, ANOVA, and a Scheffe F-test. Removal of composite from class 2 cavities resulted in significantly increased cavity volumes compared to that when amalgam was removed. While there was significant interoperator difference in cavity volumes following removal of amalgam from class 2 cavities, there was no significant interoperator difference in cavity volumes following the removal of composite. These differences were related to the methods used to eliminate the restorations from the cavities.

PMID: 8700763 [PubMed - indexed for MEDLINE]




Evaluation of 2% sodium fluoride iontophoresis as an alternative to lining in Class I cavity preparations--an in vivo study.

Evaluation of 2% sodium fluoride iontophoresis as an alternative to lining in Class I cavity preparations--an in vivo study.

J Pierre Fauchard Acad. 1994 Mar;8(1):23-8

Authors: Reddy VV, Mathew G

The study carried out on 110 permanent teeth in 44 randomly selected patients with age ranging from 8-14 years, to evaluate the efficacy of 2% sodium fluoride iontophoresis as an alternative to cavity lining in Class I preparations. 65 teeth were included in the experimental group (2% sodium fluoride iontophoresis) and 4 teeth in the control group (Zinc phosphate linings). Sensitivity gradings were done on a subjective discomfort scale. From the results, it was found that after cavity preparation, all the teeth (100%) were sensitive to air blast, water jet and probing in varying severity. But after iontophoresis and amalgam restoration the sensitivity reduced to 4.6%. Six months and nine months follow up revealed that all the teeth were vital and asymptomatic.

PMID: 9791255 [PubMed - indexed for MEDLINE]




Effect of grooves on resistance/retention form of Class 2 approximal slot amalgam restorations.

Effect of grooves on resistance/retention form of Class 2 approximal slot amalgam restorations.

Oper Dent. 1993 Sep-Oct;18(5):209-13

Authors: Summitt JB, Osborne JW, Burgess JO

This study evaluated in vitro the effectiveness of resistance/retention grooves in box-only (approximal slot) class 2 preparations. Forty-eight sound, caries-free maxillary premolars were distributed equally into four groups of 12 teeth based on faciolingual dimensions. Teeth were mounted vertically, and class 2 mesio-occlusal slot preparations were cut in each tooth. Resistance/retention grooves were placed in three of the four groups with a #1/4 round bur to a depth of 0.3-0.5 mm. Teeth were restored with amalgam and positioned 13.5 degrees from vertical; an area was flattened on each amalgam marginal ridge, and the flattened areas were loaded to failure using an Instron with a rectangular flat-ended rod at a cross-head speed of 1 mm/min. Mean load (SD) to failure of the group using "conventional" grooves extending in dentin from the gingival floor occlusally to near the occlusal DEJ was 196N (46N). For long grooves extending from the gingival floor to the occlusal surface, the mean failure load was 169N (58N). Slot restorations with short resistance/retention grooves or points (0.5-1.0 mm) just gingival to the occlusal DEJ had a mean failure load of 132N (44N). Slot restorations with no grooves had a mean failure load of 69N (46N). ANOVA and Student-Newman-Keuls tests were used for analysis. The no-groove group provided significantly less (P < 0.01) resistance than any group with grooves. Approximal slot restorations with "conventional" grooves were significantly more resistant (P < 0.01) than those with short grooves but were not significantly more resistant than those with long grooves.

PMID: 8152991 [PubMed - indexed for MEDLINE]




A comparison of glass-ionomer cement and calcium hydroxide liners in amalgam restorations.

A comparison of glass-ionomer cement and calcium hydroxide liners in amalgam restorations.

Int J Periodontics Restorative Dent. 1993 Aug;13(4):378-83

Authors: Rabchinsky J, Donly KJ

This study compared the caries inhibition and microleakage of two liners under amalgam restorations. Thirty-two molars received mesio-occlusal and disto-occlusal Class II cavity preparations. Calcium hydroxide was randomly placed as a liner in one preparation of each tooth and glass-ionomer cement liner was placed in the other. Amalgam restorations were placed. Teeth were axially loaded and an acid-protective varnish was placed. Teeth were placed into artificial saliva for 3 months, thermocycled, and cycled through a caries challenge. Sections were obtained from 20 teeth and photographed under polarized light. The remaining teeth were placed in 2% basic fuchsin and sectioned. A t-test indicated that restorations with glass-ionomer cement liners exhibited significantly less demineralization and microleakage than did restorations with calcium hydroxide liners.

PMID: 8300324 [PubMed - indexed for MEDLINE]




Class II glass ionomer cermet tunnel, resin sandwich and amalgam restorations over 2 years.

Class II glass ionomer cermet tunnel, resin sandwich and amalgam restorations over 2 years.

Am J Dent. 1993 Aug;6(4):181-4

Authors: Wilkie R, Lidums A, Smales R

This study compared the clinical behavior of a glass ionomer (polyalkenoate) silver cermet, a posterior resin composite used with the "tunnel" technique, a posterior resin composite used with the "closed sandwich" technique, and a high-copper amalgam for restoring small, proximal surface carious lesions. Two dentists placed 86 restorations in the posterior permanent teeth of 26 adults treated at a dental hospital. Restorations were assessed at 6-month intervals over 2 years for gingivitis adjacent to them, the tightness of proximal contacts, occlusal wear, surface voids, roughness and cracking, surface and marginal staining, and marginal fracture. Small filling defects, surface voids and occlusal wear were obvious with the cermet material, with surface crazing and cracking present in 48% of the tunnel restorations. Two of the posterior resin composites, but none of the amalgam restorations, also failed. The cermet cannot be recommended as a long-term permanent restorative material in situations where it is likely to be subjected to heavy occlusal stresses and abrasive wear.

PMID: 7803004 [PubMed - indexed for MEDLINE]




A comparative sealability study of different retrofilling materials.

A comparative sealability study of different retrofilling materials.

Int Endod J. 1993 Jul;26(4):241-5

Authors: Ozata F, Erdilek N, Tezel H

The purpose of this study was to compare the sealing ability of high-copper amalgam, glass ionomer cement, and silver glass ionomer cement as retrofilling materials when used with and without varnish. Seventy extracted human single-rooted anterior teeth were instrumented and the root canals obturated with laterally condensed gutta-percha and sealer. The apical 3 mm of each root was resected and a 2 mm-deep apical Class I preparation cut. The roots were then randomly allocated to six groups of 10 teeth and retrofilled with one of the experiment materials. Group I comprised high-copper amalgam; group 2, high-copper amalgam with cavity varnish; group 3, glass ionomer cement without varnish; group 4, glass ionomer cement with varnish; group 5, silver glass ionomer cement without varnish; and group 6, silver glass ionomer cement with varnish. Two groups of five roots each were used as positive and negative controls. The root surfaces were coated with nail polish and specimens immersed in 2% methylene blue solution for 14 days. After vertical sectioning, dye penetration was examined under a stereomicroscope. The results of the study were analysed statistically. The sealing ability of the conventional glass ionomer cement with varnish was significantly better while dye penetration was higher in silver glass ionomer cement without varnish group than the other groups (P < 0.01).

PMID: 8225643 [PubMed - indexed for MEDLINE]




Prevalence of postoperative sensitivity with indirect Class II resin composite inlays.

Prevalence of postoperative sensitivity with indirect Class II resin composite inlays.

ASDC J Dent Child. 1993 Mar-Apr;60(2):95-8

Authors: Kreulen CM, van Amerongen WE, Gruythuysen RJ, Borgmeijer PJ, Akerboom HB

In this clinical trial, the prevalence of postoperative sensitivity is studied in a comparison of standard size indirect class II resin composite inlays with class II amalgam restorations. Fifteen percent of the 240 restored teeth (resin composite and amalgam restorations) showed some form of sensitivity, the majority of them of a passing nature. No difference was found between amalgam and composite restorations. Molars appear to show more complaints than premolars and, rather than the restorative material applied, the patient seems to determine the results. Differences in prevalence of sensitivity between direct resin composite restorations in a previous study and the indirect restorations are discussed, using among others the differences in sensitivity that were found between the amalgam-control restorations of both studies.

PMID: 8486862 [PubMed - indexed for MEDLINE]




Effect of grooves on resistance form of Class 2 amalgams with wide occlusal preparations.

Effect of grooves on resistance form of Class 2 amalgams with wide occlusal preparations.

Oper Dent. 1993 Mar-Apr;18(2):42-7

Authors: Summitt JB, Osborne JW, Burgess JO, Howell ML

This study evaluated in vitro the necessity of retention grooves in approximal boxes in class 2 preparations with faciolingually wide occlusal extensions (occlusal isthmus width 1.8 mm). Thirty-six class 2 mesio-occlusal cavities were prepared in sound human maxillary premolar teeth and divided into three groups of 12. In one group, the preparations had no retention grooves. In another group, retention grooves 0.3-0.5 mm deep were prepared at the axioproximal line angles and extended from the gingival floor occlusally to just gingival to the occlusal dentinoenamel junction. In the third group, a 1 mm-long groove was prepared extending from the axiopulpal line angle occlusally to just gingival to the occlusal dentinoenamel junction. The marginal ridges of the amalgam were loaded at an angle of 13.5 degrees from vertical in an Instron Testing Machine until the restorations failed. Results indicated no significant difference in load to cause failure in any of the three groups. Restorations without approximal retention grooves possessed as much resistance to failure as those with grooves.

PMID: 8337180 [PubMed - indexed for MEDLINE]




Clinical aspects of restorative treatment in the primary dentition.

Clinical aspects of restorative treatment in the primary dentition.

Swed Dent J Suppl. 1993;96:1-47

Authors: Varpio M

The failure rate of restorative treatment in primary teeth was studied in a cohort of children born in 1981 and related to caries diagnosis, prevalence and distribution on different tooth surfaces, and compared with a cohort of children born in 1971. Concurrently, the longevity of composite resin in modified Class 2 cavities in primary molars was followed up and the resistance of deciduous and permanent enamel to acid adjacent to composite resin and glass polyalkeonate cement (GPA) was tested in vitro. From the 70s to the 80s, diagnostic methods changed and the examination intervals were prolonged. The number of bite-wing radiographs was halved and the participation in all six annual examinations decreased from 89% to 32%. Caries prevalence increased from 1.1 ds in 3-year-olds to 6.3 ds in 8-year-olds in Cohort '71 and, in the same ages, from 0.2 ds to 3.0 in Cohort '81. In Cohort '81, an overall decline of occlusal caries was recorded. The distal surface of the first molars was the proximal surface most often affected in both cohorts. In Cohort '81, 30% had caries-free primary teeth at the age of 8, which can be compared with 17% in the cohort 10 years earlier. In Cohort '81, the proportion of replaced proximal restorations was 14% and that of extracted molars 2%. The corresponding figures for Cohort '71 were 17% and 4%, respectively. In Cohort '81, silver amalgam was used in 65% and GPA cements in 35%. On all surfaces, silver amalgam was replaced in 22% and GPA cements in 6%. Composite resin in modified Class 2 cavities showed a cumulative success rate that declined from 86% after one year to 38% after six years. Fractures occurred early and recurrent caries was found from the second year of the follow-up. Histological investigation of these teeth disclosed bacteria subjacent to the fillings in 75% and recurrent caries in 58%. The restorations in teeth with bacterial invasion showed marginal discolouration, visible crevices or colour mismatch. In an acid environment, the enamel showed artificial caries lesions adjacent to composite resin significantly more often in primary teeth than in permanent teeth. No lesions were seen close to GPA fillings in primary teeth. The improved dental health appeared to be of greater benefit to the children and care-providers than advances in restorative treatment. The properties of GPA cements seem useful in the restorative treatment of primary teeth.

PMID: 8310420 [PubMed - indexed for MEDLINE]




Thermal conductivity of cement base materials.

Thermal conductivity of cement base materials.

Dent Mater. 1993 Jan;9(1):68-71

Authors: Drummond JL, Robledo J, Garcia L, Toepke TR

This study was designed to determine the most efficient dentin-cement-restorative material system to minimize temperature changes from either a hot (58 degrees C) or cold (4 degrees C) source. Extracted human molar teeth were used to conduct the experiment utilizing a standard Class I occlusal preparation 3.5 mm in diameter with a remaining dentin thickness of 0.5 or 1.0 mm and a control dentin thickness of 2.0 mm. A bi-electrode thermocouple was utilized with one thermocouple mounted on the roof of the pulp chamber and the other on the occlusal surface of the specimen. The cements investigated were zinc oxide and eugenol (ZOE), zinc phosphate (ZP), glass ionomer (GI), and zinc polycarboxylate (ZPC) with a thickness of either 0.5 mm or 1.5 mm. Statistical analysis consisted of a one-way analysis of variance followed by a multiple means comparison test. For heated specimens consisting of cement and dentin only, ZOE was the least effective in limiting temperature change. When cold was applied, ZOE was the most effective. Statistically for cold application, the other three cements, ZP, GI and ZPC, and 2.0 mm of dentin were the same for limiting temperature change. When amalgam was used to restore the tooth, ZOE and GI were most effective in limiting temperature change for cooled teeth. For heated teeth, all the cements were identical except for ZOE, which was the least effective. For composite restored teeth, all cements and dentin were identical in limiting temperature changes for either heating or cooling.

PMID: 8299875 [PubMed - indexed for MEDLINE]




Cariostatic and ultraconservative sealed restorations: six-year results.

Cariostatic and ultraconservative sealed restorations: six-year results.

Quintessence Int. 1992 Dec;23(12):827-38

Authors: Mertz-Fairhurst EJ, Smith CD, Williams JE, Sherrer JD, Mackert JR, Richards EE, Schuster GS, O'Dell NL, Pierce KL, Kovarik RE

The objective of this clinical study was to determine the ability of an ultraconservative, sealed composite resin restoration, without a traditional cavity preparation and without the removal of the carious lesion, to arrest Class I caries. Tooth preparation was limited to placing a bevel in the enamel. These restorations were compared, over 6 years, with (1) ultraconservative, localized, sealed amalgam restorations with no extension for prevention and (2) traditional, unsealed amalgam restorations with the usual extension for prevention outline form. Caries was arrested by the ultraconservative, sealed composite resin restorations for 6 years. Complete sealant retention on the sealed amalgam restorations was somewhat lower than that on the sealed composite resin restorations; conversely, partial sealant retention was higher for the sealed amalgam group. The marginal integrity of the sealed amalgam restorations was significantly superior to that of the unsealed amalgam restorations. The sealant also protected Class I posterior composite resin restorations against wear.

PMID: 1305301 [PubMed - indexed for MEDLINE]




Quantitation of total mercury vapor released during dental procedures.

Quantitation of total mercury vapor released during dental procedures.

Dent Mater. 1992 May;8(3):176-80

Authors: Engle JH, Ferracane JL, Wichmann J, Okabe T

An in vitro method is described in which measurements were made of the total amount of mercury vapor released from three types of amalgam during routine dental procedures. It was found that the greatest amount of mercury was released during dry polishing of one amalgam (44 micrograms). Removal of amalgam from a Class I cavity under water spray and high volume evacuation also generated large amounts of mercury as expected (15-20 micrograms). However, under the more clinically relevant conditions of extending evacuation for one minute to remove residual amalgam and mercury after cutting, this value was reduced by approximately 90%. The total amount of mercury generated during placement (6-8 micrograms), wet polishing (2-4 micrograms) and trituration (1-2 micrograms) were also measured. The study showed that dental procedures associated with amalgam do potentially expose the patient and operator to mercury vapor. However, the total amount of mercury released during any procedure was far below the total exposure level calculated from the daily threshold limits established by regulatory agencies for occupational exposure.

PMID: 1521706 [PubMed - indexed for MEDLINE]




Radiographic assessments of Class II resin composite restorations in a clinical study: baseline results.

Radiographic assessments of Class II resin composite restorations in a clinical study: baseline results.

ASDC J Dent Child. 1992 Mar-Apr;59(2):97-107

Authors: Kreulen CM, van Amerongen WE, Akerboom HB, Borgmeijer PJ, Gruythuysen RJ

In this article, the baseline results of radiographic evaluation of both Class II resin composite and Class II amalgam restorations are discussed. Attention is paid to the quality of the cervical margin adaptation, the occurrence of radiolucencies adjacent to the restoration, and the homogeneity of the resin composite.

PMID: 1583203 [PubMed - indexed for MEDLINE]




Effect of grooves on resistance form of conservative Class 2 amalgams.

Effect of grooves on resistance form of conservative Class 2 amalgams.

Oper Dent. 1992 Mar-Apr;17(2):50-6

Authors: Summitt JB, Howell ML, Burgess JO, Dutton FB, Osborne JW

This study evaluated several means of providing retention for the approximal box in very conservative class 2 preparations (occlusal isthmus width 0.7 mm). Sixty class 2 mesio-occlusal cavities were prepared in sound human maxillary premolar teeth. Four types of retention grooves, 0.3-0.5 mm deep, were prepared at the axiofacial and axiolingual line angles and/or occlusal to those line angles. Specimens were loaded at an angle of 13.5 degrees from vertical in an Instron Universal Testing Machine until the restoration failed. Results indicate that grooves located occlusal to the axiopulpal line angle provided more resistance than conventional grooves (gingival to the axiopulpal line angle) or no grooves. The use of a short retention groove or retention point located occlusal to the axiopulpal line angle, but not extending to the occlusal cavosurface margin, provided greater retention while removing minimal tooth structure.

PMID: 1437687 [PubMed - indexed for MEDLINE]




Current teaching of proximal retention grooves for Class II amalgam preparations.

Current teaching of proximal retention grooves for Class II amalgam preparations.

J Dent Educ. 1992 Feb;56(2):131-4

Authors: Moore DL

PMID: 1737866 [PubMed - indexed for MEDLINE]




[The effect of 2 finishing methods on the micromorphology of the proximal box margin. An in-vivo study].

[The effect of 2 finishing methods on the micromorphology of the proximal box margin. An in-vivo study].

Schweiz Monatsschr Zahnmed. 1992;102(10):1175-80

Authors: Lussi A, Hugo B, Hotz P

Minipreparations of class II cavities often are not employed in daily practice mainly because adequate instruments for finishing the axial box margin and the proximo-cervical curvature were not available. The purpose of this in vivo study was to assess the morphology of the proximal box margin after finishing with two different methods. 81 class II minicavities for amalgam restorations were prepared by 4 dental practitioners. One method for finishing the axial box margin and the proximo-cervical curved border was the use of a modified EVA-System with the total amplitude reduced to 0.4 mm and a highly flexible file (Cavishape, grain 25 microns). The other method was the use of an axial margin trimmer. The micromorphology of the two methods was investigated by means of scanning electron microscopy and a score system as described earlier (Lussi et al. 1987). The margins of the axial box as well as of the proximo-cervical curvature were significantly better finished with the EVA-System and the highly flexible file compared to the axial margin trimmer (p < 0.001). The finishing time for the box margin was not significantly different using the EVA instrument or the axial margin trimmer. These findings confirm other in vitro investigations. This in vivo study shows that the modified EVA instrument with the highly flexible file (Cavishape, grain 25 microns) is clearly superior to the axial margin trimmer in finishing the box margin. This device allowed a significant better finishing of the axial box margin and the proximo-cervical curvature of minicavities in daily practice.

PMID: 1439693 [PubMed - indexed for MEDLINE]






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