Restoring biological width in crown-root fracture: A periodontal concern.

J Indian Soc Pedod Prev Dent. 2007 Sep;25 Suppl:S20-4

Authors: Nandlal B, Daneswari V

A 10-year-old male child reported to J.S.S. Dental College and Hospital presenting with a vertical crown-root fracture of maxillary central incisor with a history of fall 10 days back. A new treatment protocol was attempted in contrary to various schools of thoughts of coronal fragment removal wherein fractured fragments were approximated and internally reinforced with latest technologies in adhesive dentistry, the goal was to save the tooth, restore its function and esthetics. This case presents the above mentioned philosophy.

PMID: 17921636 [PubMed - in process]

Effect of air abrasion on tensile bond strength of a single-bottle adhesive/indirect composite system to enamel.

Braz Dent J. 2007;18(1):45-8

Authors: Silva PC, Gonçalves M, Nascimento TN, Centola AL

This study evaluated the efficiency of air abrasion alone and associated with phosphoric acid etching on tensile bond strength of a single-bottle adhesive/indirect composite restorative system (Bond 1/Alert) to human enamel. Forty enamel surfaces from extracted human third molars were assigned to 4 groups (n= 10). Mach 4.1 (Kreativ Inc.) air abrasion equipment was used for 20 s. A special system of rod pairs aligned in a specific apparatus was used for tensile strength tests, according to ISO/TR 11405 standard (1994) with some modifications. Bond strength means were: G1 (air abrasion + rinsing + condensable composite resin Alert) = 3.46 +/- 0.83 MPa; G2 (air abrasion + rinsing + Bond 1 adhesive system + Alert) = 4.00 +/- 1.60 MPa; G3 (air abrasion + rinsing + 37% phosphoric acid + rinsing + Bond 1 + Alert) = 20.80 +/- 3.95 MPa; and G4 (37% phosphoric acid + rinsing + Bond 1 + Alert) = 17.00 +/- 2.74 MPa. The statistical analysis by Kruskal-Wallis test revealed that G1 and G2 presented statistically significant difference (p< 0.05) from G3 and G4 (p<0.01) and G1 and G3 did not differ significantly (p> 0.05) from G2 and G4, respectively.

PMID: 17639200 [PubMed - indexed for MEDLINE]

Dentin bond strength of composites with self-etching adhesives using LED curing lights.

J Contemp Dent Pract. 2007;8(5):34-42

Authors: Korkmaz Y, Attar N

AIM: The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with halogen LCUs on the shear bond strength (SBS) of one nanofill composite (Filtek Supreme) and one microhibrid composite (Artemis) with self-etch adhesives. METHODS AND MATERIALS: The buccal surfaces of 60 non-carious extracted human molars were flattened to expose dentin and, subsequently, polished for 60 seconds with 600-grit wet silicon carbide abrasive paper. Specimens were assigned into six groups (n=10) according to composite material, self-etch adhesive, and curing light used as follows: Group 1: Adper Prompt L-Pop (AP) and Filtek Supreme (FS) using an Elipar Free Light (EFL); Group 2: AP and FS using an Elipar Free Light 2 (EFL2); Group 3: AP and FS using a Hilux Expert (HE) light, Group 4: AdheSE (AS)+Artemis (AR) using an EFL; Group 5: AS+AR using an EFL2; and Group 6: AS+AR using a HE light. The specimens were thermocycled for 500 cycles (5 masculineC-55 masculineC) and then loaded to failure in a Zwick universal testing machine at a crosshead speed of 5 mm/minute. SBS values were calculated as megapascals (MPa) and statistically analyzed using the one-way analysis of variance (ANOVA) test at a significance level of 0.05. RESULTS: Mean SBS (+/- standard deviations) values were as follows: Group1: 15.99+/-5.18; Group 2: 18.76+/-6.71; Group 3: 17.70+/-5.04; Group 4: 16.93+/-3.99; Group 5: 18.01+/-5.19, and Group 6: 17.46+/-5.40. There were no statistically significant differences for SBS to dentin among the groups tested. CONCLUSION: The LED curing lights used in the study seem to be comparable with the halogen curing light for nanofill and microhybrid composites used in conjunction with self-etching systems in dentin. The EFL2 reduces curing time, which can be considered as an advantage.

PMID: 17618328 [PubMed - indexed for MEDLINE]

Chlorhexidine's effect on sealing ability of composite restorations following Er:YAG laser cavity preparation.

J Contemp Dent Pract. 2007;8(5):26-33

Authors: Geraldo-Martins VR, Robles FR, Matos AB

AIM: The aim of this study was to evaluate the influence of chlorhexidine on microleakage of composite restorations in class V cavities prepared with a carbide bur (CB) and a erbium:yttrium-aluminum-garnet (Er:YAG) laser. METHODS AND MATERIALS: Cavity preparations were created on the buccal surfaces of 48 bovine incisors using different methods then equally dividing them into four groups. Groups I and II were prepared with a #56 CB in a high speed handpiece while Groups III and IV were prepared with a Er:YAG laser at 350m J/4Hz on enamel and at 80.24 J/cm2 on dentin. The cavity preparations were rinsed with 2% chlorhexidine solution before the application of Clearfill SE Bond system and placement of a Z100 composite resin restoration. After 24 hours, the teeth were polished, thermocycled, and sealed with cosmetic varnish. The samples were then immersed in 2% methylene blue for four hours and sectioned in the buccolingual direction to determine the degree of microleakage. RESULTS: After statistical analysis (Kruskal-Wallis, p<0.05), no significant differences were verified among the tested groups and between the evaluated cervical or incisal margins of the restoration. CONCLUSION: The use of the chlorhexidine did not interfere with the adhesion process regardless of whether a CB or the Er:YAG laser were used to prepare class V cavities when restored with the tested self-etching adhesive system.

PMID: 17618327 [PubMed - indexed for MEDLINE]

[Clinical effect of pit and fissure sealant used in combination with self-etching adhesive on permanent teeth]

Shanghai Kou Qiang Yi Xue. 2006 Dec;15(6):571-4

Authors: Peng SM, Zhao W, Lin JC, Ling JQ

PURPOSE: To determine the role of pit and fissure sealant used in combination with self-etching adhesive in retention of the sealants and caries decrease of the permanent teeth. METHODS: Sixty two children aged 6-14 years old were chosen from the outpatients in the Department of Pediatric Dentistry, the first or the second permanent molars (n= 156) were sealed with two kinds of sealant. The tooth in one side was sealed with sealant (Concise, 3M-ESPE) and self-etching system (Adper and Prompt, 3M-ESPE) while the tooth in the other side was sealed with sealant (Concise, 3M-ESPE) and phosphate acid system. All the patients were followed up and reexamined 3, 6 and 12 months after treatment. Statistical analysis was carried out with SPSS 12.0 (SPSS Inc., Chicago, IL, USA) software package for Chi-square test and t test. RESULTS: The operating time using self-etching system was (122 +/- 13)s, shorter than (219 +/- 13)s using phosphate acid system (P < 0.05). The self-etching system used only one step to finish etching, adhesion and treatment of tooth surface, saving the steps of rinsing and drying. The retention rates of pit and fissure sealant in self-etching system and phosphate acid system were 97.4% and 96.2% respectively at the third month, 94.9% and 92.3% at the sixth month, 91.0% and 88.4% at the end of one year after treatment. The prevalence rate of caries in both groups had no significant difference (P>0.05); No caries in both groups were found in the first three months; In patients using self-etching system, caries decreased by 100% at the sixth month and by 50% at the end of one year. CONCLUSION: Adper Prompt self-etching adhesive, with an advantage of simple operation and shorter operation period, is effective in bonding sealant to the enamel. The retention rates of pit and fissure sealant were not different between the two groups.

PMID: 17533704 [PubMed - in process]

Healing of periodontal flaps when closed with silk sutures and N-butyl cyanoacrylate: a clinical and histological study.

Indian J Dent Res. 2007 Apr-Jun;18(2):72-7

Authors: Kulkarni S, Dodwad V, Chava V

BACKGROUND: The closure of the periodontal flaps post-surgery is a necessity for attainment of a primary union between the flap margins and the establishment of a healthy dentogingival junction. N-butyl cyanoacrylate is a tissue adhesive, which can be used for the closure of the incised wounds to overcome the problems associated with conventional suture materials like silk. OBJECTIVE: The present study was carried out to assess the healing of the periodontal flaps when closed with the conventional silk sutures and N-butyl cyanoacrylate. MATERIALS AND METHODS: The study was carried out on 24 patients who needed flap surgical procedure for pocket therapy. RESULTS: It was found that healing with the cyanoacrylate is associated with less amount of inflammation during the first week when compared with silk. However, over a period of 21 days to 6 weeks, the sites treated with both the materials showed similar healing patterns. CONCLUSION: It can be concluded that cyanoacrylate aids in early initial healing.

PMID: 17502712 [PubMed - indexed for MEDLINE]

A rational use of dental materials in posterior direct resin restorations in order to control polymerization shrinkage stress.

Minerva Stomatol. 2007 Mar;56(3):129-38

Authors: Giachetti L, Bertini F, Bambi C, Scaminaci Russo D

One of the main problems when using resin-based composites is the resulting polymerization shrinkage stress. Composite strain is hindered every time the composite is bonded to the tooth's walls. In the pre-gel phase the shrinkage stress is reduced by the composite flow from the free to the bonded surface areas. Therefore, no stress develops at the dentine-composite interface. When a gel point is reached, the composite flow no longer compensates for the volumetric shrinkage. The generated stress may cause adhesive failure and several other adverse clinical consequences such as enamel fracture, cracked cusps, cuspal movement, microcracking of the restorative material and gaps between the resin and cavity walls which may cause secondary caries and postoperative sensitivity. A sensible use of materials in direct restorations may contribute to a reduced rate of shrinkage stress. To this aim glass-ionomer cement as well as flowable, light-curing and self-curing composites were examined. The aim of this study was to provide some useful information for a sensible choice of restoration materials in order to control shrinkage stress and its negative consequences in direct posterior restorations.

PMID: 17327817 [PubMed - indexed for MEDLINE]

Bond strength to deep coronal dentin: effect of bonding strategies.

Minerva Stomatol. 2007 Mar;56(3):105-14

Authors: Giovannone T, Migliau G, Bedini R, Ferrari M, Gallottini L

AIM: The aim of this study was to evaluate bond strength at the composite-adhesive-deep dentin interface following pre-treatment with sodium hypochlorite using 4 different types of enamel-dentin adhesive and a composite for the core. METHODS: From 60 healthy human molars, cylindrical samples (3 mm high) were obtained using a special slow-speed saw. Cavities with 2-5-mm diameters were made in all the samples. Samples were assigned to 8 groups, 4 groups were designated as experimental groups and were irrigated with NaOCl and the other 4 groups designated as control groups were irrigated with distilled water. Adhesive systems were applied to the samples and then restored using a core build-up composite. Samples were subjected to shear stress test using an electronic dynamometer. RESULTS: The data were analyzed using one-way ANOVA and the Tukey test (P<0.05). The results, in terms of bond strength, demonstrate that the two-step self-etch adhesive systems generate a stronger bond than the other systems considered in the study (P<0.05). The results also show that pre-treatment with hypochlorite does not seem to influence the bond strength of self-etch adhesive systems. CONCLUSIONS: This in vitro study demonstrates that there exist differences in bond strength between self-etch and etch & rinse adhesive systems on deep dentin pretreated with sodium hypochlorite to simulate endodontic treatment.

PMID: 17327814 [PubMed - indexed for MEDLINE]

Effect of centripetal and incremental methods in Class II composite resin restorations on gingival microleakage.

J Contemp Dent Pract. 2007;8(2):113-20

Authors: Ghavamnasiri M, Moosavi H, Tahvildarnejad N

AIM: The aim of this study was to evaluate the microleakage at gingival margins below the cementoenamel junction (CEJ) of Class II composite restorations using various placement techniques. METHODS AND MATERIALS: Sound human maxillary premolars were selected. Eighty slot-style cavities on the mesial or distal surfaces were prepared with the cervical margins located apical to the CEJ. The specimens were divided into two groups based on the restorative technique utilized (centripetal or incremental). Each group was then categorized into two subgroups according to the type of matrix used resulting in a total of four experimental groups as follows: IP=Incremental and Palodent matrix, IT = Incremental and Transparent matrix, CP= Centripetal and Palodent matrix, and CT = Centripetal and Transparent matrix. Following restoration with a total etch adhesive (Single Bond) and a resin composite (Z100), the teeth were thermocycled. Then specimens were immersed in 0.5% basic fuchsin dye for 24 hours at a temperature of 37 degrees C. Sectioned restorations were examined under a stereomicroscope (40X magnification), and the extent of the microleakage was scored and recorded. Data were analyzed using the Kruskal-Wallis non-parametric statistical test (P=0.05). RESULTS: In the four groups of the study no significant differences in the mean rank of microleakage were observed (p>0.05). CONCLUSION: When the gingival margin was located on cementum, the kind of matrix and filling technique did not reduce the microleakage.

PMID: 17277834 [PubMed - indexed for MEDLINE]

A comparison of two different methods and materials used to repair polycarbonate crowns.

J Contemp Dent Pract. 2007;8(2):105-12

Authors: Yilmaz A

AIM: The aim of this study was to evaluate the bond strength and crown-repair material interface of polycarbonate crown repaired using flowable resin composite and hybrid resin composite following two different surface preparations. METHODS AND MATERIALS: The facial surfaces of fifty-two polycarbonate crowns were flattened and roughened. Specimens were then divided into four test groups. A bonding agent alone (Groups 1 and 2) or a combination of methylmethacrylate (MMA) + bonding agent (Groups 3 and 4) was applied to the prepared surfaces. Then either a flowable (Groups 1 and 3) or a microfilled hybrid (Groups 2 and 4) resin composite was placed on the surfaces. Forty-eight of the original fifty-two specimens were used for shear bond strength testing. Failure types (adhesive, cohesive, and mixed) were evaluated. The remaining four specimens, one from each group, were used for crown-resin composite interface analysis using a scanning electron microscope (SEM). RESULTS: There were significant differences in both mean shear bond strength values and failure types (P<0.05). The SEM evaluation revealed a close interface relationship in Groups 3 and 4. CONCLUSION: MMA monomer application on a polycarbonate crown prior to application of an adhesive agent improved the shear bond strength of the repair material.

PMID: 17277833 [PubMed - indexed for MEDLINE]

The effect of thermocycling on the adhesion of self-etching adhesives on dental enamel and dentin.

J Contemp Dent Pract. 2007;8(2):17-24

Authors: El-Araby AM, Talic YF

AIM: The aim of the present study was to investigate the effectiveness of one total-etch self-priming adhesive and two one-step self-etching adhesive systems on the adhesion of a resin composite to both dentin and enamel. The effect of thermocycling on the adhesion was also investigated. The null hypothesis tested was thermocycling would not affect bond strengths to enamel and dentin treated with self-etching adhesives or a total-etch adhesive. METHODS AND MATERIALS: Two single-step self-etching adhesives [Xeno III (XE3) and Prompt L-Pop (PP)] and one two-step total-etch adhesive system (Prime & Bond NT) (P&B NT) were used in this study. Thirty caries-free unrestored human third molars were used to make specimens of enamel and dentin. Different adhesives were applied on enamel and dentin surfaces according to the manufacturer's instructions then hybrid composite restorative material was condensed on the surface using a mold. The bonded specimens were stored in distilled water at 37 masculineC for 24 hours before being tested. Half of the bonded specimens were tested for shear bond strength without thermocycling. The other half of the test specimens were thermocycled using a thermocycling apparatus in water baths held at 5 masculineC and 55 masculineC with a dwell time of one minute each for 10,000 cycles prior to shear testing. The mean shear bond strength before and after thermocycling was calculated, and the results were subjected to two-way analysis of variance (ANOVA) and repeated measure design to show the interaction between different materials and different times. RESULTS: The results showed shear bond strength on both enamel and dentin of the total-etch adhesive and the self-etching adhesives decreased after the specimens were subjected to thermocycling. CONCLUSIONS: The null hypothesis tested "thermocycling would not affect bond strengths treated with self-etching adhesives" was rejected. Furthermore, the study revealed the following: 1. The shear bond strength to both enamel and dentin of the total-etch adhesive and the self-etching adhesives decreased after the specimens were subjected to thermocycling. 2. XE3 achieved the highest bond strength to both enamel and dentin (26.994+/-1.17 and 25.22+/-1.26, respectively). 3. XE3 showed even better bonding after thermocycling to enamel and dentin than the total-etching system or PP. 4. Although PP bonded to enamel showed lower shear bond strength value than XE3, it has durable bond strength even after thermocycling.

PMID: 17277823 [PubMed - indexed for MEDLINE]

Fatigue strength of fragmented incisal edges restored with a fiber reinforced restorative material.

J Contemp Dent Pract. 2007;8(2):9-16

Authors: Garoushi SK, Lassila LV, Vallittu PK

AIM: The aim of this study was to determine the compressive fatigue limits (CFLs) of fractured incisor teeth restored using either a conventional adhesive-composite technique or using fiber-reinforced composites (FRCs). METHODS AND MATERIALS: Fifteen extracted sound upper incisor teeth were prepared by cutting away the incisal one-third part of their crowns horizontally. The teeth were restored using three techniques. Group A (control group) was restored by reattaching the original incisal edge to the tooth. Group B was restored using particulate filler composite (PFC). Group C was restored with PFC and FRC by adding a thin layer of FRC to the palatal surface of the teeth. The bonding system used was a conventional etch system with primer and adhesive. All restored teeth were stored in water at room temperature for 24 h before they were loaded under a cyclic load with a maximum controlled regimen using a universal testing machine. The test employed a staircase approach with a maximum of 103 cycles or until failure occurred. Data were analyzed using analysis of variance (ANOVA) (p=0.05). Failure modes were visually examined. RESULTS: Group A (reattaching fractured incisal edge) revealed the lowest CFL values, whereas the creation of a new incisal edge with PFC revealed a 152% higher CFL value compared to Group A. Group C (teeth restored with FRC) revealed a 352% higher CFL than the control group. ANOVA revealed the restoration technique significantly affected the compressive fatigue limit (p<0.001). The failure mode in Group A and B was debonding of the restoration from the adhesive interface. While in Group C, the sample teeth fractured below their cemento-enamel junctions. CONCLUSION: These results suggested an incisally fractured tooth restored with the combination of PFC and FRC-structure provided the highest CFL.

PMID: 17277822 [PubMed - indexed for MEDLINE]

Surface roughness of a dental ceramic after polishing with different vehicles and diamond pastes.

Braz Dent J. 2006;17(3):191-4

Authors: Camacho GB, Vinha D, Panzeri H, Nonaka T, Gon&#xE7;alves M

During fabrication of bonded ceramic restorations, cervical adaptation, occlusal adjustment and final finishing/polishing are procedures to be performed at the dental office after adhesive cementation. Final adjustments may result in loss of ceramic glaze, which requires new polishing of the ceramic surface, with special attention for selection of adequate materials and instruments. The purpose of this study was to evaluate the efficiency of different vehicles associated with diamond pastes indicated for dental ceramic polishing. Two polishing pastes (Crystar Paste and Diamond Excell) associated with four vehicles (rubber cup, Robinson bristle brush, felt wheel and buff disc) were evaluated. Disc-shaped specimens were fabricated from Ceramco II dental ceramic. Surface roughness means (Ra) of the ceramic specimens were determined with a rugosimeter. Data were analyzed statistically by two-way ANOVA and Tukey's test at 5% significance level. There was no statistically significant difference (p>0.01) between the polishing pastes. However, there were statistically significant differences (p<0.01) among the tested vehicles. Vehicle-paste interaction showed statistically significant difference (p<0.05) as well. It may be concluded that: 1) Robinson bristle brush, felt wheel and buff disc were efficient vehicles to be used in association with a diamond polishing paste; 2) The use of rubber cup as a vehicle showed poor efficiency for mechanical polishing of the ceramic surfaces; 3) Both pastes provided similar and efficient polishing and may be recommended for use with an appropriated vehicle.

PMID: 17262123 [PubMed - indexed for MEDLINE]

Effect of refrigeration on bond strength of self-etching adhesive systems.

Braz Dent J. 2006;17(3):186-90

Authors: Borges GA, Spohr AM, de Oliveira WJ, Correr-Sobrinho L, Correr AB, Borges LH

The purpose of this study was to investigate the tensile bond strength to dentin of three self-etching adhesive systems at refrigerated and room temperatures. Seventy-eight bovine incisors were embedded in self-cured acrylic resin, abraded on a water-cooled lathe and polished with 400- and 600-grit sandpapers to obtain standard dentin surfaces. The specimens were randomly assigned to 6 groups (n=13). Clearfil SE Bond, AdheSE and One-Up Bond F adhesive systems at refrigerated (4 degrees C) and room temperatures (23 degrees C) were applied to dentin according to the manufacturers' instructions. A truncated composite resin (Herculite XRV) cone was bonded to dentin surface. The specimens were stored in distilled water at 37 degrees C for 24 h and submitted to tensile bond strength testing at a crosshead speed of 0.5 mm/min. Means in MPa were analyzed statistically by Student's t-test at 5% significance level. No statistically significant differences (p>0.05) were found between the adhesive systems applied at refrigerated and room temperatures. In conclusion, no adverse effects on tensile bond strength were observed when self-etching adhesive systems were used after being taken directly from the refrigerated storage.

PMID: 17262122 [PubMed - indexed for MEDLINE]

Morphological characterization of the tooth/adhesive interface.

Braz Dent J. 2006;17(3):179-85

Authors: Moura SK, Santos JF, Ballester RY

The purpose of this study was to assess the morphological characteristics of the tooth/adhesive interface using different adhesive systems in MOD restorations under scanning electron microscopy (SEM). The tested hypothesis was that the morphology of the bonding interface would vary in different areas of MOD restorations for the three adhesive systems. MOD cavities were prepared in 12 sound extracted human third molars and restored with Filtek Z250 composite resin and one of the following adhesive systems: Experimental ABF (n=4), Clearfil SE Bond (n=4) self-etching primers and Single Bond etch-and-rinse adhesive system (n=4). After 24-h storage in distilled water at 37 degrees C, teeth were sectioned and prepared for SEM. The interfacial morphology varied depending on the adhesive system and also on the evaluated area. The null hypothesis was accepted because the morphology of the tooth/adhesive interface reflected the characteristics of both the dental substrate and the adhesive systems.

PMID: 17262121 [PubMed - indexed for MEDLINE]

Retention of radicular posts varying the application technique of the adhesive system and luting agent.

Braz Oral Res. 2006 Oct-Dec;20(4):347-52

Authors: Fonseca TS, Alfredo E, Vansan LP, Silva RG, Sousa YT, Saquy PC, Sousa-Neto MD

This study evaluated in vitro the retention of intracanal cast posts cemented with dual-cure resin varying the application method of the primer/adhesive solution and luting agent in the prosthetic space prepared to receive the posts. Sixty endodontically treated maxillary canines had their crowns discarded, and their roots were embedded in acrylic resin. The prosthetic spaces were prepared with Largo burs mounted on a low-speed handpiece coupled to a parallelometer in order to maintain length and diameter of intraradicular posts constant and to guarantee that the preparations were parallel after casting. Two groups (n = 30) were randomly formed according to the device used to apply the adhesive system: microbrush or standard bristle brush (control). Each group was divided into 3 subgroups (n = 10) according to the technique used to place the luting agent into the root canal: using only a lentulo spiral before setting the post, applying it onto the post surface, or combining both methods. After 72 hours, the tensile force required to dislodge each post was determined by a universal testing machine (Instron 4444) set at a speed of 1 mm/min. The results indicated that the use of the microbrush yielded higher bond strength values (0.1740 +/- 0.04 kN) than those recorded for the bristle brush tip (0.1369 +/- 0.04 kN, p < 0.001). Bonferroni's test demonstrated a higher retention (p < 0.001) in radicular post cemented with the technique that combined both methods (lentulo + post: 0.1787 +/- 0.03 kN) than that obtained with lentulo (0.1461 +/- 0.065 kN) or post (0.1416 +/- 0.03 kN) alone. The interactions between the adhesive system and luting agent application techniques presented statistical difference (p < 0.001). It was concluded that the best performance in terms of tensile strength among the tested conditions was obtained when the adhesive system was applied with a microbrush and the luting agent was taken into the root canal with lentulo spirals alone (0.1961 +/- 0.04 kN) and combining both methods (lentulo + post: 0.1911 +/- 0.02 kN).

PMID: 17242797 [PubMed - indexed for MEDLINE]

Effect of metal priming agents on bonding characteristics of an acrylic resin joined to SUS XM27 steel.

J Oral Sci. 2006 Dec;48(4):215-8

Authors: Ishikawa Y, Kawamoto Y, Koizumi H, Furuchi M, Matsumura H, Tanoue N

The purpose of the current study was to evaluate the effect of functional monomers contained in the primers on adhesive bonding of a steel alloy. SUS XM27 steel was primed with one of the following materials; Alloy Primer, Estenia Opaque Primer, and V-Primer. The functional monomers in the primers were a phosphate (10-methacryloyloxydecyl dihydrogen phosphate; MDP) and a thione (6-(4-vinylbenzyl-n-propyl) amino-1,3,5-triazine-2,4-dithione, -dithiol tautomer; VTD) for Alloy Primer, MDP alone for Estenia, and VTD alone for V-Primer. The steel disks were bonded with an acrylic resin (Unifast Trad), and bond strength was determined. Of the three primers, both the Alloy Primer (33.3 MPa) and Estenia Opaque Primer (33.9 MPa) materials exhibited far better post-thermocycling bond strength than V-Primer (0 MPa). It can be concluded that the phosphate MDP is effective, whereas the thione VTD is ineffective for bonding SUS XM27 steel.

PMID: 17220619 [PubMed - indexed for MEDLINE]

Effect of different types of enamel conditioners on the bond strength of orthodontic brackets.

J Contemp Dent Pract. 2007 Jan 1;8(1):36-43

Authors: Davari AR, Yassaei S, Daneshkazemi AR, Yosefi MH

AIM: A unique characteristic of some new bonding systems in operative dentistry is they combine conditioning and priming agents into a single acidic primer solution for simultaneous use on both enamel and dentin. Combining conditioning and priming into a single treatment step results in improvement in both time and cost-effectiveness to the clinician and, indirectly, to the patient. The purpose of this study was to determine the effects of the use of a self-etching primer on the bond strength of orthodontic brackets and on the bracket/adhesive failure mode. METHODS AND MATERIALS: Thirty-six fresh bovine incisors were collected and stored in a solution of 0.1% (weight/volume) thymol. The criteria for tooth selection included intact buccal enamel, no cracks caused by the presence of the extraction forceps, and no defects. The teeth were cleansed and polished with pumice and rubber prophylactic cups for ten seconds. Brackets were bonded to the teeth according to one of three protocols following the manufacturers' instructions--Group 1: Conventional multistep bonding system (control group) (n=12); Group 2: Self-etching primer system (n=12); and Group 3: Acid+self-etching primer system (n=12). Specimens were loaded to failure in a Zwick test machine (Zwick GmbH & Co, Ulm, Germany). Shear bond strengths were measured at a crosshead speed of 5 mm/min. RESULTS: The mean shear bond strength in megapascals (Mpa) (standard deviation) were 11.7 (4.2), 10.5 (4.4), and 10.9 (4.8) for Groups 1, 2, and 3, respectively. The analysis of variance (ANOVA) was used to compare the three groups. The results indicated no significant difference in the bond strength between the three groups (P=0.800). The results of the Chi square test, evaluating the residual adhesives on the enamel surfaces, revealed no significant difference between the three groups (P=0.554). CONCLUSION: Results of the present in vitro study indicate the use of self-etching primers may be an alternative to conventional phosphoric acid pre-treatment in orthodontic bonding.

PMID: 17211503 [PubMed - indexed for MEDLINE]

A randomized clinical trial comparing 'one-step' and 'two-step' orthodontic bonding systems.

J Orthod. 2006 Dec;33(4):276-83; discussion 256-7

Authors: Manning N, Chadwick SM, Plunkett D, Macfarlane TV

OBJECTIVE: The primary objective of this prospective clinical trial was to assess the clinical bond failure rates of orthodontic brackets bonded using a self-etching primer (SEP), compared with brackets bonded using a conventional acid-etched technique with control adhesive (Transbond). A secondary aim was to investigate whether characteristics of the operator, patient or tooth bonded had any influence on bracket failure. DESIGN: Single-centre randomized controlled clinical trial. Thirty-four patients were bonded, each being randomly assigned to either the test or control adhesive. SETTING: NHS Hospital Orthodontic Department, Chester, UK. SUBJECTS: Orthodontic patients requiring fixed appliance treatment. MAIN OUTCOME MEASURES: Bond failure. MAIN OUTCOME RESULTS: Failure rates over the initial 6-month period were 2.0% (Transbond) and 1.7% (SEP) with no statistically significant difference between the two groups. Over the duration of the fixed appliance treatment, bond failure rates increased, but remained acceptable at 7.4 % (TB) and 7.0% (SEP), respectively. When operator, patient and tooth characteristics were analysed, only the bracket location was found to be significant. Maxillary brackets were more likely to fail than mandibular brackets (RR 0.47%; 95% CI 0.22, 1.03). The failure rate for brackets in our study was low when compared with previous studies. CONCLUSIONS: Both the acid-etched control and self-etching primer in combination with adhesive pre-coated brackets were successful for clinical bonding. Their combined failure rate was lower than that reported in similar trials.

PMID: 17142334 [PubMed - indexed for MEDLINE]

Electric-current-assisted application of self-etch adhesives to dentin.

J Dent Res. 2006 Dec;85(12):1092-6

Authors: Breschi L, Mazzoni A, Pashley DH, Pasquantonio G, Ruggeri A, Suppa P, Mazzotti G, Di Lenarda R, Tay FR

The use of electric current during the application of etch-and-rinse adhesive systems has been recently claimed to increase bonding of etch-and-rinse adhesives by enhancing substrate impregnation. The null hypothesis tested in this study was that electrically assisted application has no effect on bond strength of self-etching bonding systems. Three self-etch adhesives (Protect-Bond, Xeno III, and Prompt L-Pop) were applied with the aid of an electric signal-generating device (ElectroBond) and tested vs. controls prepared with the same disposable sponges but without electric current. Specimens bonded under the influence of electric current exhibited increased microtensile bond strength compared with the controls (p<0.05). High-resolution SEM analysis showed that bonding under the influence of electricity reduced interfacial nanoleakage. It is speculated that resin infiltration may be improved by the attraction of polar monomers by an electric current or by modification of the dentin surface charges, resulting in better water substitution or evaporation.

PMID: 17122160 [PubMed - indexed for MEDLINE]

Effect of the number of coats of simplified adhesive systems on microleakage of dentin-bordered composite restorations.

J Contemp Dent Pract. 2006 Nov 1;7(5):34-41

Authors: Harada TS, Pazinatto FB, Wang L, Atta MT

AIM: This study tested the null hypothesis that there is no difference on microleakage of dentin-bordered composite restorations using single or double coats of adhesive from one-bottle adhesive systems. METHODS AND MATERIALS: The enamel surface was removed from freshly extracted bovine teeth, and standardized Class V cavities (3 x 3 x 1.5 mm) were made at the cervical areas of buccal surfaces. Teeth were restored and grouped according to type of adhesive systems [Prime Bond 2.1 (PB2.1), Prime & Bond NT (PBNT), and Single Bond (SB)] and to the number of coats (one or two) to be used. The restorations were polished and immersed in a 0.5% aqueous solution of basic fuchsin for four hours. Teeth were then sectioned and the most infiltrated section of each tooth was selected under magnification, scanned, and quantitatively analyzed using a computer program. Data were analyzed using two-way analysis of variance (ANOVA) and Student-Newman-Keuls (a=0.05). RESULTS: Groups without filler content (PB2.1 and SB) showed no difference in microleakage using single or double coats. However, PBNT (with nanofiller) showed statistically less microleakage when only one coat was applied. The influence of the number of coats of the adhesive systems on dentin margin microleakage was material dependent. CONCLUSION: All adhesive systems demonstrated microleakage, however, it could be minimized using two coats of non-filled or one coat of a filled adhesive system.

PMID: 17091138 [PubMed - indexed for MEDLINE]

Microleakage of seven adhesive systems in enamel and dentin.

J Contemp Dent Pract. 2006 Nov 1;7(5):26-33

Authors: Silveira de Ara&#xFA;jo C, Incerti da Silva T, Ogliari FA, Meireles SS, Piva E, Demarco FF

AIM: The aim of this study was to evaluate the microleakage of seven adhesive systems on two substrates (enamel and dentin). METHODS AND MATERIALS: Class V cavities were performed in buccal and lingual surfaces of 56 bovine incisors. The cervical margin was located in dentin and the incisal margin in enamel. The specimens were randomly divided into seven groups (n=16), according to the adhesive system employed: Single Bond; Excite; One Step Plus; Gluma One Bond; Magic Bond; One Up Bond F; and One Coat Bond. The cavities were incrementally filled with a hybrid composite Filtek Z250 and polymerized with a XL 3000 light curing unit. After polishing, the specimens were submitted to thermal cycling followed by dye immersion. Leakage was evaluated under magnification (40X) based on a standard ranking. Data were subjected to statistical analysis (Kruskal-Wallis). RESULTS: Enamel margins exhibited lower leakage than dentin margins (p<0.01). The majority of the specimens were leakage-free and materials performed similarly. Conversely, in dentin most of the specimens exhibited the highest leakage degree and significant differences among materials (p<0.05) were found, with Excite exhibiting the lowest leakage degree. It was concluded enamel provided better sealing and the adhesive system was a significant factor only in dentin.

PMID: 17091137 [PubMed - indexed for MEDLINE]

The effect of two different polishing techniques on microleakage of new composites in Class V restorations.

J Contemp Dent Pract. 2006 Nov 1;7(5):18-25

Authors: Yal&#xE7;in F, Korkmaz Y, Başeren M

AIM: The purpose of this study was to investigate the effect of polishing systems on the microleakage of a nanofill, a nanohybrid, and a microhybrid composite in Class V cavities. METHODS AND MATERIALS: Preparations were made at the cemento-enamel junction (CEJ) of 36 extracted human premolars. The teeth were randomly divided into three groups and restored with new resin composites according to the manufacturers' instructions as follows: Group 1, Filtek Supreme & Single Bond; Group 2, Grandio & Solobond; and Group 3, Artemis & Excite. The restorations were finished with diamond finishing burs. The restored/finished teeth were randomly divided into two groups and polished using the following systems: Super-Snap (Al2O2 coated, abrasive disc system, fine grit, and extra fine grit) and Astropol/Astrobrush (silicon-based abrasive polisher point and polisher brush). All specimens were thermocycled 1000 times with a 10 second dwell time. They were immersed in 0.5% aqueous basic fuchsin dye for 24 hours and then sectioned buccal-lingual-longitudinally through the center of both restorations of each tooth and evaluated under a stereomicroscope at 30X magnification. The degree of dye penetration was quantified. RESULT: No significant difference in leakage scores was observed in enamel margins (p=0.456, Kruskall Wallis test), but dentin margins were significantly affected by the different polishing systems (p=0.037, Kruskall Wallis test). The lower leakage scores were recorded for Astropol/Astrobrush polishing systems. The nanofill composite showed the least leakage among the test groups in this study. The most leakage was observed in nanohybrid composite resin (p<0.05, Mann Whitney U test). CONCLUSIONS: Under the conditions of this in vitro study: the microleakage resistance of composites at enamel margins is not significantly affected by the different polishing systems; the lowest leakage scores were recorded for Astropol/Astrobrush polishing techniques in different types of composites; and the ranking of the composite materials from most to least leakage at the dentin margins according to polishing techniques was Grandio >Artemis > Filtek Supreme.

PMID: 17091136 [PubMed - indexed for MEDLINE]

Apparent interfacial fracture toughness of resin/ceramic systems.

J Dent Res. 2006 Nov;85(11):1037-41

Authors: Della Bona A, Anusavice KJ, Mecholsky JJ

We suggest that the apparent interfacial fracture toughness (K(A)) may be estimated by fracture mechanics and fractography. This study tested the hypothesis that the K(A) of the adhesion zone of resin/ceramic systems is affected by the ceramic microstructure. Lithia disilicate-based (Empress2-E2) and leucite-based (Empress-E1) ceramics were surface-treated with hydrofluoric acid (HF) and/or silane (S), followed by an adhesive resin. Microtensile test specimens (n = 30; area of 1 +/- 0.01 mm(2)) were indented (9.8 N) at the interface and loaded to failure in tension. We used tensile strength (sigma) and the critical crack size (c) to calculate K(A) (K(A) = Ysigmac(1/2)) (Y = 1.65). ANOVA and Weibull analyses were used for statistical analyses. Mean K(A) (MPa.m(1/2)) values were: (E1HF) 0.26 +/- 0.06; (E1S) 0.23 +/- 0.06; (E1HFS) 0.30 +/- 0.06; (E2HF) 0.31 +/- 0.06; (E2S) 0.13 +/- 0.05; and (E2HFS) 0.41 +/- 0.07. All fractures originated from indentation sites. Estimation of interfacial toughness was feasible by fracture mechanics and fractography. The K(A) for the systems tested was affected by the ceramic microstructure and surface treatment.

PMID: 17062746 [PubMed - indexed for MEDLINE]

Influence of moisture conditions on dentin bond strength of single-step self-etch adhesive systems.

J Oral Sci. 2006 Sep;48(3):131-7

Authors: Chiba Y, Rikuta A, Yasuda G, Yamamoto A, Takamizawa T, Kurokawa H, Ando S, Miyazaki M

This study was conducted to clarify the influence of dentin surface moisture on bond strength of single-step self-etch adhesive systems. The adhesive systems used were Adper Prompt L-Pop (AP), Clearfil tri-S Bond (CT), Fluoro Bond Shake One (FB), G-Bond (GB), and One-Up Bond F Plus (OF). Bovine mandibular incisors were wet-ground with #600 SiC to expose the labial dentin. After rinsing with tap water, the dentin surface was dried with air for 10 sec (Dry condition) or blotted (Wet condition). Adhesives were applied according to each manufacturer's instructions, followed by resin composite polymerization. Ten samples per test group were stored in distilled water at 37 degrees C for 24 h, then shear tested at a crosshead speed of 1.0 mm/min. The data were analyzed by Student's t test and Tukey HSD test at a probability level of 0.05. The mean bond strengths for Dry condition ranged from 13.9 MPa to 18.2 MPa, and those for Wet condition ranged from 7.1 MPa to 18.4 MPa. Significantly lower bond strengths were obtained for the Wet condition for GB, FB, and OF. Failure after the test was commonly due to adhesive breakdown associated with partial cohesive failure in the dentin. These data suggest that air-drying of the dentin surface is appropriate for the adhesive systems tested.

PMID: 17023745 [PubMed - indexed for MEDLINE]

Influence of surface roughness on crack formation in a glass-ceramic bonded to a resin composite base.

J Oral Sci. 2006 Sep;48(3):125-30

Authors: Yamamoto T, Nishiura R, Momoi Y

The objective of the present study was to assess the influence of the roughness of a loaded surface on crack formation in a mica-based glass-ceramic bonded to a resin composite base. Five different surface roughnesses were created on glass-ceramic discs by serial wet-grinding with silicone carbide abrasives. The thicknesses of the ceramic discs were 1.50 +/- 0.01 mm. Resin composite discs were bonded to the ceramic surfaces opposite to the ground surfaces using an adhesive resin composite cement and a silane coupling agent. A compressive load was then applied at the center of the ground ceramic surface. The loads at initial radial and cone crack formations in the ceramic were measured macroscopically. In three of the five groups, the initial radial crack formations could not be observed due to the high roughness of these surfaces. Statistical analysis was performed using Student's t test for initial radial cracks and one-way ANOVA for the cone cracks. There were no significant differences between the two groups for the initial radial cracks or among the five groups for the cone cracks (P < 0.05). The roughness of the loaded surface had no influence on crack formation in the bonded mica-based glass-ceramic.

PMID: 17023744 [PubMed - indexed for MEDLINE]

In vitro microtensile bond strength of four adhesives tested at the gingival and pulpal walls of Class II restorations.

J Am Dent Assoc. 2006 Oct;137(10):1414-8

Authors: Purk JH, Healy M, Dusevich V, Glaros A, Eick JD

BACKGROUND: The authors compared the microtensile bond strength of teeth restored with four adhesives at the gingival and pulpal cavity walls of Class II resin-based composite restorations. METHODS: Five pairs of extracted third molars received two Class II preparations/restorations in each tooth. The authors randomly assigned each preparation to one of four adhesive groups: Adper Scotchbond Multipurpose Dental Adhesive (SBMP) (3M ESPE, St. Paul, Minn.), Clearfil SE Bond (CFSE) (Kuraray America, New York City), Prime & Bond NT (PBNT) (Dentsply Caulk, Milford, Del.) and PQ1 (Ultradent, South Jordan, Utah). They restored the teeth and obtained microtensile specimens from each cavity wall. Specimens were tested on a testing machine until they failed. RESULTS: The mean (+/- standard deviation) bond strengths (in megapascals) were as follows: SBMP (pulpal), 36.4 (17.2); SBMP (gingival), 29.7 (15.3); CFSE (pulpal), 50.8 (13.6); CFSE (gingival), 50.2 (14.0); PBNT (pulpal), 38.3 (19.2); PBNT (gingival), 38.9 (17.7); PQ1 (pulpal), 58.7 (8.7); and PQ1 (gingival), 54.5 (18.5). A two-way analysis of variance found an adhesive effect (P < .001) but no location effect (P >.05). CONCLUSIONS: PQ1 and CFSE performed the best. The results showed no significant difference in microtensile bond strength at the gingival wall versus the pulpal wall. CLINICAL IMPLICATIONS: Under in vitro conditions, a total-etch ethanol-based adhesive (PQ1) failed cohesively more often than did the other adhesives tested.

PMID: 17012721 [PubMed - indexed for MEDLINE]

A review of polymerization shrinkage stress: current techniques for posterior direct resin restorations.

J Contemp Dent Pract. 2006 Sep 1;7(4):79-88

Authors: Giachetti L, Scaminaci Russo D, Bambi C, Grandini R

In general excellent results cannot be guaranteed when using resin-based composites for posterior restorations. This is due to polymerization shrinkage which can still be regarded as the primary negative characteristic of composite resins. A review of available literature regarding the polymerization process, its flaws, and suggested strategies to avoid shrinkage stress was conducted. Several factors responsible for the polymerization process may negatively affect the integrity of the tooth-restoration complex. There is no straightforward way of handling adhesive restorative materials that can guarantee the reliability of a restoration. At present, the practitioner has to coexist with the problem of polymerization shrinkage and destructive shrinkage stress. However, evolving improvements associated with resin-based composite materials, dental adhesives, filling, and light curing techniques have improved the predictability of such restorations. This critical review paper is meant to be a useful contribution to the recognition and understanding of problems related to polymerization shrinkage and to provide clinicians with the opportunity to improve the quality of composite resin restorations.

PMID: 16957794 [PubMed - indexed for MEDLINE]

Effect of different bonding conditions on the shear bond strength of two compomers to bovine dentin.

J Contemp Dent Pract. 2006 Sep 1;7(4):9-16

Authors: Al-Nahedh H, Ateyah NZ

AIM: Despite the improvements to compomer materials, the bond strength of these materials remains inferior to "composite/resin bonding" systems and limits their clinical use. The purpose of this study was to evaluate the effect of acidic conditioning with phosphoric acid and Prompt L-Pop (PLP) on the shear bond strength of two compomers Dyract AP (DAP) and Composan Glass (CG) to dentin. METHODS AND MATERIALS: Sixty extracted bovine teeth were used to test the shear bond strength of two compomers to flat dentin labial surfaces. The dentin specimens were randomly assigned to six groups of ten specimens each: Group 1: DAP and Prime & Bond NT (PBNT); Group 2: DAP/PBNT with a 15 second dentin etch prior to bonding; Group 3: DAP placed with PLP adhesive; Group 4: CG and Compobond NE (CBNE); Group 5: CG/CBNE with a 15 second dentin etch; and Group 6: CG placed with PLP adhesive. The specimens were stored at 37 masculineC with 100% humidity for 24 hours then mounted and sheared using an Instron Universal Testing Machine at a cross head speed of 0.5 mm/min. The results were recorded in Mega Pascals (MPa). The sheared specimens were examined under a light microscope, and the type of failure (adhesive, cohesive, or mixed) was recorded. RESULTS: The mean dentin shear bond strength value (MPa) for the groups was: Group 1 (11.6+/-3.9); Group 2 (13.2+/-3.3); Group 3 (12.4+/-2.0); Group 4 (13.0+/-4.3); Group 5 (19.3+/-3.7); and Group 6 (13.1+/-3.0). One way analysis of variance (ANOVA) and Tukey HSD post-hoc tests detected a significantly higher bond strength (P = 0.003) for group 5. For groups 1, 3, 4, and 6, the mode of failure was mostly adhesive. When acid etching of dentin was performed (groups 2 and 5), cohesive fracture within dentin was the predominant mode of failure. Acid etching and the use of PLP significantly reduced the number of adhesive fractures and reduced variability in the shear bond strength results. CONCLUSIONS: Acid etching significantly increased the shear bond strength of CG to dentin but did not affect DAP. The application of PLP resulted in a shear bond strength not statistically different from PBNT or CPNE. CG bond to dentin is improved with acid etching using phosphoric acid. However, PLP provided no significant improvement in the shear bond strength of DAP and CG.

PMID: 16957786 [PubMed - indexed for MEDLINE]

The evolution of the CEREC system.

J Am Dent Assoc. 2006 Sep;137 Suppl:7S-13S

Authors: M&#xF6;rmann WH

BACKGROUND AND OVERVIEW: Early in 1980, the author anticipated the attraction of restoring posterior teeth with tooth-colored material. He conducted studies and developed the clinical concept of bonded ceramic inlays, at the same time raising the issue of the fast fabrication of the ceramic restorations. The author developed plans for in-office computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication of ceramic restorations specifically to enable the dentist to complete one or multiple ceramic restorations chairside, in a single appointment. The initial concept comprised a small mobile CAD/CAM unit integrating a computer, keyboard, trackball, foot pedal and optoelectronic mouth camera as input devices, a monitor and a machining compartment. CEREC 3 (Sirona Dental Systems GmbH, Bensheim, Germany) divided the system into an acquisition/design unit and a separate machining unit. Three-dimensional software makes the handling illustrative and easy both in the office and in the laboratory. CONCLUSIONS: It appears that the CEREC CAD/CAM concept is becoming a significant part of dentistry. CLINICAL IMPLICATIONS: Sound knowledge of adhesive bonding and diligent planning are essential for the successful integration of CAD/CAM into clinical dental offices.

PMID: 16950932 [PubMed - indexed for MEDLINE]

Adhesive analysis of voids in Class II composite resin restorations at the axial and gingival cavity walls restored under in vivo versus in vitro conditions.

Dent Mater. 2007 Jul;23(7):871-7

Authors: Purk JH, Dusevich V, Glaros A, Eick JD

OBJECTIVES: Adhesive analysis, under the scanning electron microscope of microtensile specimens that failed through the adhesive interface, was conducted to evaluate the amount of voids present at the axial versus gingival cavity walls of class II composite restorations restored under in vivo and in vitro conditions. METHODS: Five patients received class II resin composite restorations, under in vivo and in vitro conditions. A total of 14 premolar teeth yielded 59 (n=59) microtensile adhesive specimens that fractured through the adhesive interface. The fractured surfaces of all specimens were examined and the % area of voids was measured. RESULTS: Voids at the adhesive joint were highly predictive of bond strengths. An increase in the number of voids resulted in a decrease in the microtensile bond strength. The area of voids at the adhesive interface was as follows: in vivo axial 13.6+/-25.6% (n=12); in vivo gingival 48.8+/-29.2% (n=12); in vitro axial 0.0+/-0.0% (n=19) and in vitro gingival 11.7+/-17.6% (n=16). SIGNIFICANCE: Composite resin may bond differently to dentin depending upon the amount of voids and the cavity wall involved. The bond to the gingival wall was not as reliable as the bond to the axial wall. An increase in the amount of surface voids was a major factor for reducing microtensile bond strengths of adhesive to dentin.

PMID: 16950506 [PubMed - indexed for MEDLINE]

Effect of eugenol-based endodontic cement on the adhesion of intraradicular posts.

Braz Dent J. 2006;17(2):130-3

Authors: Alfredo E, de Souza ES, Marchesan MA, Paulino SM, Gariba-Silva R, Sousa-Neto MD

The present study evaluated, in vitro, the influence of an eugenol-based endodontic sealer (EndoFill) on the adhesion of intra-radicular posts cemented with a resin-based cement (Enforce) ou a zinc phosphate cement. Twenty-four single-rooted maxillary canines were divided into 2 groups (n=12) and obturated with either gutta-percha points plus EndoFill or gutta-percha points alone (no cement). In each group, half of intracanal posts (n=6) were cemented with Enforce resin-based cement and half with zinc phosphate cement. Specimens were submitted to pull-out test in an Instron machine and tensile force was applied at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal was recorded (N) and means were submitted to statistical analysis by Kruskal-Wallis test (p<0.01). Posts cemented with zinc phosphate cement were significantly more retentive (353.4 N) than those cemented with Enforce (134.9 N) (p<0.01). Regarding the influence of the eugenol-based cement (EndoFill) on post retention, there was statistically significant difference (p<0.01) only between the groups cemented with Enforce, i.e., in the canals filled with EndoFill + guta-percha there was lower bond strength than in the canals filled with gutta-percha points alone (101.5 and 168.2 N, respectively). In conclusion, the zinc-phosphate-based cement showed greater post retention than the resin-based cement. The findings of this study suggest that the eugenol-containing sealer interfered with the adhesive properties of the resin-based cement.

PMID: 16924340 [PubMed - indexed for MEDLINE]

Effect of thermal cycling on bond strengths of single-step self-etch adhesives to bovine dentin.

J Oral Sci. 2006 Jun;48(2):63-9

Authors: Asaka Y, Yamaguchi K, Inage H, Takamizawa T, Kurokawa H, Rikuta A, Kuroda T, Miyazaki M

The purpose of this study was to clarify the effect of thermal cycling on dentin bond strengths of single-step self-etch adhesives. Five commercially available single-step self-etch systems were used. The adhesives were applied to the dentin surfaces of bovine incisors, and then light-irradiated. Resin composites were condensed into a mold and light-irradiated. Bonded specimens were divided into two groups and stored in water at 37 degrees C for 24 h without thermal cycling, or in water at 37 degrees C for 24 h followed by 10,000 thermal cycles between 5 degrees C and 60 degrees C. Ten samples per group were tested for shear strength at a crosshead speed of 1.0 mm/min. The data were analyzed by Student's t test and Tukey HSD test at a probability level of 0.05. After 24 h of storage in water, the mean dentin bond strengths ranged from 9.3 MPa to 14.0 MPa. After 10,000 thermal cycles, the mean bond strengths remained unchanged. Failure after the test was commonly due to adhesive breakdown associated with partial cohesive failure of the resin. The present results suggest that the benefit of using single-step self-etch systems, in terms of simplifying the clinical procedure, might be acceptable even after thermal stresses.

PMID: 16858134 [PubMed - indexed for MEDLINE]

Effect of enamel preparations on fracture resistance of composite resin buildup of fractures involving dentine in anterior bovine teeth: an in vitro study.

J Indian Soc Pedod Prev Dent. 2006 Jun;24(2):69-75

Authors: Gandhi K, Nandlal B

Sixty bovine teeth with simulated mesio-incisal angle fracture were randomly and equally divided in one untreated (control) group and three experimental groups (Bevel, Chamfer and newly introduced Stair-step Chamfer preparation group) to evaluate the effect of enamel preparations on the fracture resistance of composite resin. Post restoration, fracture mechanics approach was used to quantify the failure of composite resins in testing the samples in Instron testing machine. Mean peak failure load (Newton) of composite amongst experimental groups was observed in the order; Chamfer (326.09 +/- 72.73), Stair-step chamfer (315.21 +/- 81.77) and Bevel (253.83 +/- 67.38). Results of the One-Way ANOVA revealed significant difference in the mean peak failure load values of the four different groups. (P<0.001) Scheffe's Post-Hoc comparison test (Subset for alpha = 0.05) revealed that there was no significant difference in the mean peak failure load values of the bevel, stair-step chamfer and chamfer preparation when considered together, but the mean peak values of control group (605.22 +/- 48.96) were observed significantly higher. Failure mode evaluation revealed, majority of failures occurred as cohesive and mixed type for all the experimental groups. Adhesive type failure was observed maximum (33%) in the bevel group. Stair-step chamfer preparation showed greatest potential for application and use as it no only demonstrated comparable values to Chamfer preparation ['t' value (0.39) (P > 0.05)] but also involved sacrificing less amount of tooth structure adjacent to fractured edge.

PMID: 16823230 [PubMed - indexed for MEDLINE]

Oral surgery with fibrin sealants in patients with bleeding disorders: a case report.

J Contemp Dent Pract. 2006 Jul 1;7(3):106-12

Authors: Filho Ade M, dos Santos RS, Costa JR, Puppin AA, de Rezende RA, Beltr&#xE3;o GC

Surgical treatment of patients with bleeding disorders requires careful planning. The use of fibrin sealants following a dental extraction in a patient with von Willebrand's disease is presented in this report. A female patient with von Willebrand's disease had an extraction of a maxillary right third molar. After evaluation by the surgeon and the hematologist, the surgery was performed with a topical application of fibrin sealant and systemic administration of antifibrinolytic drugs. Hemostasis was obtained without replacement of plasma clotting factor. New techniques of achieving hemostasis in patients with bleeding disorders using fibrin sealants have been successfully used in oral surgery without replacement of plasma clotting factors or changes in anticoagulant therapy.

PMID: 16820814 [PubMed - indexed for MEDLINE]

Effects of surface conditioning on bond strength of metal brackets to all-ceramic surfaces.

Eur J Orthod. 2006 Oct;28(5):450-6

Authors: Türk T, Saraç D, Saraç YS, Elekdağ-Türk S

The aim of this study was to determine the effectiveness of bonding brackets to ceramic restorations. Sixty feldspathic and 60 lithium disilicate ceramic specimens were randomly divided into six groups. Shear bond strength (SBS) and bond failure types were examined with six surface-conditioning methods: silane application to glazed surface, air particle abrasion (APA) with 25- and 50-microm aluminium trioxide (Al(2)O(3)), etching with 9.6 per cent hydrofluoric acid (HFA), and roughening with 40- and 63-microm diamond burs. Silane was applied to all roughened surfaces. Metal brackets were bonded with light cure composite, then stored in distilled water for 1 week and thermocycled (x500 at 5-55 degrees C for 30 seconds). The ceramic surfaces were examined with a stereomicroscope at a magnification of x10 to determine the amount of composite resin remaining using the adhesive remnant index. The lowest SBS values were obtained with HFA for feldspathic (5.39 MPa) and lithium disilicate (11.11 MPa) ceramics; these values were significantly different from those of the other groups. The highest SBS values were found with 63-microm diamond burs for feldspathic (26.38 MPa) and lithium disilicate (28.20 MPa) ceramics, and were not significantly different from 40-microm diamond burs for feldspathic and lithium disilicate ceramics (26.04 and 24.26 MPa, respectively). Roughening with 25- and 50-microm Al(2)O(3) particles showed modest SBS for lithium disilicate (22.60 and 26.15 MPa, respectively) and for feldspathic ceramics (17.90 and 14.66 MPa, respectively). Adhesive failures between the ceramic and composite resin were noted in all groups. Damage to the porcelain surfaces was not observed. The SBS values were above the optimal range, except for feldspathic ceramic treated with HFA and silane. With all surface-conditioning methods, lithium disilicate ceramic displayed higher SBS than feldspathic ceramic.

PMID: 16772317 [PubMed - indexed for MEDLINE]

A randomised clinical trial to investigate bond failure rates using a self-etching primer.

Eur J Orthod. 2006 Oct;28(5):444-9

Authors: Murfitt PG, Quick AN, Swain MV, Herbison GP

This clinical trial evaluated, over a 12-month period, the performance of brackets bonded to teeth etched and primed with Transbond Plus Self-Etching Primer (SEP) when compared with a conventional separate two-step etch and primer system. Thirty-nine randomly selected patients requiring fixed appliance therapy were entered into the study. Random allocation of each etching system, along with a 'split-mouth cross-quadrant' design was used. A total of 661 brackets were placed by two operators. The failure and survival rates of the brackets were determined for age and gender of the patients, each etching system, operator, mode of failure, tooth position in the dental arch, and number of manipulations prior to curing the adhesive. Statistical analysis showed that SEP had a significantly higher bond failure rate (11.2 per cent) than the conventional etch and primer system (3.9 per cent) at the P = 0.001 level. Cox's proportional hazards regression showed the conventional etch and primer system to have a 60 per cent reduced chance of bracket failure over a 12-month observation period, while males had a 2.4 times increased risk compared with females. The predominant mode of failure was at the composite enamel interface for the SEP, while for the conventional etch and primer system, it was within the composite adhesive. No statistically significant differences were found for the failure rate with respect to the age of the patient, operator, tooth location, or the number of manipulations of the bracket. This in vivo study showed that brackets bonded using SEP had an increased clinical bond failure rate compared with the conventional, separate, etch and prime system.

PMID: 16763088 [PubMed - indexed for MEDLINE]

Evaluation of an antimicrobial and fluoride-releasing self-etching primer on the shear bond strength of orthodontic brackets.

Eur J Orthod. 2006 Oct;28(5):457-61

Authors: Korbmacher H, Huck L, Adam T, Kahl-Nieke B

The enhanced risk of dental caries is one negative side-effect of fixed appliances. A new antimicrobial and fluoride-releasing self-etching bonding system (Clearfil Protect Bond) has been introduced in restorative dentistry and clinical studies have already shown the potential for this primer to be used clinically with effective antiplaque properties. Therefore, this in vitro study was conducted in order to evaluate the new primer in comparison with a conventional bonding preparation. One hundred and twenty extracted human teeth were randomly divided into three groups of 40 specimens each (20 incisors, 20 premolars). In group 1 a conventional bonding procedure was used (etching, Transbond XT), in group 2 the new primer was used according to the manufacturer's recommendations when bonding to intact enamel, while in group 3 the new primer was used without prior etching. Shear bond strength (SBS) was measured with a universal testing machine and the adhesive remaining after debonding was determined using an optical microscope at x10 magnification. The adhesive remnant index was used in order to assess the mode of failure. No enamel fractures were detected in any of the specimens. In all groups acceptable bond strengths were observed. The only statistically significant difference (P = 0.004) was found for the incisors in group 2, which showed the highest mean SBS (17.46 MPa). Considering the acceptable bond strength and the mode of failure, use of the new primer without prior etching is recommended in patients with fixed appliances. Further in vivo studies will be carried out in order to evaluate clinical performance.

PMID: 16763086 [PubMed - indexed for MEDLINE]

An in-vitro investigation into the use of a single component self-etching primer adhesive system for orthodontic bonding: a pilot study.

J Orthod. 2006 Jun;33(2):116-24

Authors: House K, Ireland AJ, Sherriff M

OBJECTIVE: This pilot study assessed force to debond (N); time, and site of bond failure of a single component self-etching primer (SEP) and adhesive system, Ideal 1 (GAC International Inc., USA) and compared it with the conventional acid etch and rinse regimen using 37% o-phosphoric acid solution and either Transbond XT (3M Unitek) or Ideal 1 adhesive. DESIGN: In vitro laboratory study. SETTING: Bristol Dental Hospital, UK. Sept 2003-Sept 2004. MATERIAL AND METHODS: Nine groups of 20 premolars were bonded using metal orthodontic brackets using three protocols: (1) 37% o-phosphoric acid etch and Transbond XT adhesive; (2) 37% o-phosphoric acid and Ideal 1 adhesive; (3) Ideal 1 SEP and Ideal 1 adhesive. Force to debond and locus of bond failure were determined at three time intervals. RESULTS: Enamel pre-treatment prior to bonding, namely SEP versus conventional etching had no significant effect on the median force to debond with the Ideal 1 adhesive. Similarly, when the enamel was conventionally etched, the adhesive type, namely Ideal 1 or Transbond XT, had no significant effect on the measured force to debond. However, there appeared to be differences in the locus of bond failure: failure predominated at the enamel/adhesive interface for the Transbond XT conventional etch group and at adhesive/bracket interface for the Ideal 1 SEP and adhesive group and the Ideal 1 adhesive conventional etch group. CONCLUSION: These results suggested that the complete Ideal 1 SEP and adhesive system might be successful in vivo leading therefore to a clinical trial. However, implications for clean up time are discussed and improvements to in vitro study designs are advised.

PMID: 16751433 [PubMed - indexed for MEDLINE]

Effect of dentinal surface preparation on bond strength of self-etching adhesive systems.

Braz Oral Res. 2006 Jan-Mar;20(1):52-8

Authors: Rocha PI, Borges AB, Rodrigues JR, Arrais CA, Giannini M

The aim of this study was to evaluate the effects of dentin surface treatments on the tensile bond strength (TBS) of the self-etching primer Clearfil SE Bond (CSE) and the one-step self-etching One-Up Bond F (OUB). The exposed flat dentin surfaces of twenty-four sound third molars were prepared with diamond bur at high-speed, carbide bur at low-speed or wet ground with #600 grit SiC paper. The adhesive systems were applied to the dentin surfaces and light-cured according to the manufacturers' instructions. A 6-mm high composite crown was incrementally built-up and each increment was light-cured for 40 seconds. After being stored in water (37 degrees C/24 h), the samples were serially sectioned parallel to the long axis, forming beams (n = 20) with a cross-sectional area of approximately 0.8 mm(2). The specimens were tested in a Universal Testing Machine at 0.5 mm/min. The cross-sectional area was measured and the results (MPa) were analyzed by two-way ANOVA and Tukey Test (p < 0.05). Overall, the groups treated with CSE exhibited the highest TBS for all surface treatments. Dentin surfaces prepared with carbide bur at low speed reduced TBS in the CSE group; however, OUB was not affected by surface treatments. The effect of surface abrasive methods on TBS was material-dependent.

PMID: 16729175 [PubMed - indexed for MEDLINE]

Effects of Tissucol and epsilon aminocaproic acid in the healing process following dental extraction in dehydrated rats.

Braz Oral Res. 2006 Jan-Mar;20(1):33-9

Authors: Okamoto T, Alves-Rezende MC, Cl&#xE1;udio CC, Rodrigues Tda S, Okamoto R

A histological study was conducted of the alveolar bone healing process following tooth extraction of dehydrated rats after the implantation of fibrin adhesive (TISSUCOL) associated to previous irrigation of the wound with a 5% epsilon aminocaproic acid solution (EACA). Seventy two rats were used, divided into three groups receiving different treatments after the surgical procedure. In group I, the gingival mucosa was sutured after extraction of the right upper incisor. In groups II and III, chronic dehydration was produced by water deprivation for 9 days (3 days in the preoperative period and 6 days in the postoperative period). In the animals of Group II, after tooth extraction, the gingival mucosa was sutured in the same way as performed in group I. In group III, after extraction, the dental socket was irrigated with 5% EACA, followed by implantation of the fibrin adhesive (TISSUCOL). The mucosa was sutured in the same way as performed in the other groups. At 3, 7, 15 and 21 postoperative days, the animals were sacrificed in number of 6 for each group. Specimens containing the dental socket were removed and fixed in 10% formalin and decalcified in an equal part formic acid and sodium citrate solution. After routine processing, the specimens were embedded in paraffin for microtomy. We obtained 6 microm semi-serial slices that were stained with hematoxylin and eosin for histological evaluation. The results showed that the water deprivation in the pre- and postoperative periods caused a delay in the alveolar bone healing process. The use of the fibrin adhesive (TISSUCOL) produced an improvement in the fibrinolytic picture caused by dehydration.

PMID: 16729172 [PubMed - indexed for MEDLINE]

Bond strength of total-etch and self-etch dentin adhesive systems on peripheral and central dentinal tissue: a microtensile bond strength test.

J Contemp Dent Pract. 2006 May 1;7(2):26-36

Authors: Yeşilyurt C, Bulucu B

OBJECTIVE: The purpose of this study was to evaluate the microtensile bond strength (mu TBS) of four total-etch adhesives [Excite (EB), Prime&Bond NT (PBNT), Single Bond (SB), and One Coat Bond (OCB)] by comparing them to five self-etching adhesives (Clearfil SE Bond (CSEB), Xeno III (X III), Prompt L-Pop (PLP), AQ Bond (AQB), and Tyrian/One Step plus (TOSP)] at different dentinal areas. In addition the interface between the adhesive resins and dentin was examined using scanning electron microscopy (SEM). METHODS AND MATERIALS: Superficial occlusal dentin of extracted human molars was exposed and finished with wet 800-grit silicon carbide paper. A block of composite resin was then bonded to the molar samples with the above adhesives according to the manufacturers' instructions. After 24 hours in water at 37 degrees C, the specimens were sectioned into 1 mm thick slices and divided into two regional subgroups according to their relationship to pulp tissue using visual criteria: pulp center and pulp periphery. The slices were then trimmed for the microtensile bond test and subjected to a tensile force and crosshead speed of 1 mm/min. Two-way analysis of variance was performed for statistical analyses. In addition the bond strengths for nine adhesive systems for each dentinal area were compared using the Post-Hoc test. The resin-dentin interfaces for each adhesive system were observed under a SEM. RESULTS: Mean mu TBS ranged from (25.2 MPa) for TOSP to (48.9 MPa) for PBNT. The bond strengths of total-etch adhesive systems were not significantly different, and were higher than self-etch adhesive systems, except for CSEB (p<0.05). No significant regional difference was observed for all of the nine adhesive systems (p>0.05). SEM observation showed there is not a standard hybridization for adhesive systems. CONCLUSION: Different dentinal areas may not exhibit as great an influence on bond strengths using new adhesive systems.

PMID: 16685292 [PubMed - indexed for MEDLINE]

Evaluation of shear bond strength and SEM observation of all-in-one self-etching primer used for bonding of fissure sealants.

J Contemp Dent Pract. 2006 May 1;7(2):9-16

Authors: Al-Sarheed MA

OBJECTIVES: To evaluate and compare enamel shear bond strength of an all-in-one self-etching primer (Prompt L-Pop) to regular acid etch material when bonded to two-fissure sealant systems (Concise and Dyract Seal). METHOD AND MATERIALS: Forty newly extracted non-carious first permanent molars were embedded in a Teflon mold. The teeth were divided into four groups and each consisted of ten specimens. The bonding surfaces were treated with either Prompt L-Pop as recommended by the manufacturer or etched with phosphoric acid. After 24 hours of water storage, the specimens were evaluated for shear bond strength using an Instron testing machine. Scanning electron microscope (SEM) examinations were carried out to evaluate the failure sites of the sealants. RESULTS: The mean shear bond strengths using Prompt L-Pop were Concise: 23.46 MPa and Dyract Seal: 20.34 MPa. These values were higher than and statistically different from those of Dyract Seal (9.99 MPa) and Concise (8.85 MPa) when phosphoric acid was used. The failure was predominantly of the adhesive type. The SEM examination showed the failure of debonding was predominantly related to the type of etching systems used rather than the type of fissure sealants. CONCLUSION: The use of the all-in-one self-etching adhesive Prompt L-Pop improves the mean enamel shear bond strength of fissure sealants.

PMID: 16685290 [PubMed - indexed for MEDLINE]

Hydrolysis of functional monomers in a single-bottle self-etching primer--correlation of 13C NMR and TEM findings.

J Dent Res. 2006 May;85(5):422-6

Authors: Nishiyama N, Tay FR, Fujita K, Pashley DH, Ikemura K, Hiraishi N, King NM

Self-etching primers/adhesives that combine acidic methacrylate monomers with water in a single bottle are hydrolytically unstable and require refrigeration to extend their shelf-lives. This study tested the null hypothesis that one year of intermittent refrigeration of a 4-MET-containing simplified self-etching primer does not result in hydrolytic changes that are identifiable by transmission electron microscopy and (13)C NMR spectroscopy. Human dentin was bonded with UniFil Bond immediately after being unpacked, or after one year of intermittent refrigeration at 4 degrees C. Fresh and aged primers were analyzed by NMR for chemical changes. Ultrastructural observations indicated that there was an augmentation in etching capacity of the aged adhesive that was not accompanied by resin infiltration or effective polymerization. New NMR peaks detected from the aged ethanol-based primer confirmed that degradation occurred initially via esterification with ethanol, followed by hydrolysis of both ester groups in the 4-MET. Hydrolysis of functional methacrylate monomers occurs despite intermittent refrigeration.

PMID: 16632754 [PubMed - indexed for MEDLINE]

Influence of light intensity on dentin bond strength of self-etch systems.

J Oral Sci. 2006 Mar;48(1):21-6

Authors: Yamamoto A, Tsubota K, Takamizawa T, Kurokawa H, Rikuta A, Ando S, Takigawa T, Kuroda T, Miyazaki M

The purpose of this study was to investigate the influence of light intensity on dentin bond strengths of four self-etch adhesive systems. The light intensities used to polymerize specimens were controlled at levels of 150, 300, 600, and 900 mW/cm2. The two-step self-etch adhesive systems Imperva Fluoro Bond and Mac Bond II, and the one-step self-etch systems Fluoro Bond Shake-One and One-Up Bond F Plus were used with their corresponding light-cured resins. Labial surfaces of lower bovine incisors were ground with #600 grit SiC paper to expose the dentin. The dentin surfaces were treated according to each manufacturer's instructions and bonded with resin composites. A shear bond strength test was performed and the data were analyzed by one-way ANOVA followed by Newman-Keuls multiple comparison at a level of 0.05. Statistical analysis of the data indicated that light intensity affected the dentin bond strengths of the adhesive systems tested. Significantly lower bond strengths were obtained by exposure to 150 mW/cm2, and there were no differences between the bond strengths obtained at 600 and 900 mW/cm2 for all the adhesive systems used. Further research will be required to clarify the irradiance-dependent properties of light-cured resin adhesive systems.

PMID: 16617197 [PubMed - indexed for MEDLINE]

Resin tag length of one-step and self-etching adhesives bonded to unground enamel.

Bull Tokyo Dent Coll. 2005 Aug;46(3):43-9

Authors: Sundfeld RH, de Oliveira CH, da Silva AM, Briso AL, Sundfeld ML

Length of resin tags yielded by utilization of an one-step conventional adhesive system and self-etching adhesive system on unground enamel was observed. In study Groups I and III, the enamel surface was etched for 60 seconds with 35% phosphoric acid gel and adhesive systems PQ1 (Ultradent Products, Inc) and Adper Prompt L Pop (3M/ESPE) were applied. Adper Prompt L Pop (3M/ESPE) was also applied in Group II in accordance with the manufacturer's recommendations. After application of these adhesive systems to dental enamel, specimens were prepared for light microscopy analysis to ascertain degree of penetration (x400). The results were submitted to an analysis of variance at the 5% level; whenever there was significance, the Tukey test was applied at the 5% level. It was found that acid etching prior to application of conventional and self-etching adhesive materials provided higher penetration of the adhesive into the unground enamel surface compared to that achieved solely by application of self-etching adhesive.

PMID: 16598180 [PubMed - indexed for MEDLINE]

Development of a self-etch adhesive for resin-modified glass ionomers.

J Dent Res. 2006 Apr;85(4):349-53

Authors: Coutinho E, Van Landuyt K, De Munck J, Poitevin A, Yoshida Y, Inoue S, Peumans M, Suzuki K, Lambrechts P, Van Meerbeek B

The favorable self-adhesiveness of resin-modified glass ionomers (RMGIs) might be even further improved if the time-consuming and technically sensitive etch-and-rinse pre-treatment step with polyalkenoic acids could be avoided. We undertook this study to assess the effectiveness of an experimental self-etch adhesive for RMGIs that does not need to be rinsed off. Ultrastructural analysis and micro-tensile bond strength testing to enamel and dentin of a RMGI restorative material and a RMGI adhesive were performed after 4 different surface pre-treatments: no conditioning; 25% polyalkenoic acid; an experimental self-etch adhesive; and 37.5% phosphoric acid followed by the experimental self-etch adhesive. The use of an experimental self-etch adhesive increased the bond strength of RMGIs, especially after an additional conditioning step. Interfacial analysis showed the formation of a thin hydroxyapatite-containing hybrid layer. The self-etch technique enhances the user-friendliness of RMGIs and lowers their technique-sensitivity, while maintaining desirable characteristics of the conventional etch-and-rinse approach with polyalkenoic acids.

PMID: 16567557 [PubMed - indexed for MEDLINE]

Influence of cavity dimensions, insertion technique and adhesive system on microleakage of Class V restorations.

J Am Dent Assoc. 2006 Feb;137(2):197-202

Authors: Costa Pfeifer CS, Braga RR, Cardoso PE

BACKGROUND: The authors evaluated the influence of cavity dimensions, insertion technique and adhesive system on microleakage of Class composite restorations. METHODS: The authors prepared cylindrical cavities with enamel margins of 3-millimeter diameter by 1-mm depth or 6-mm diameter by 2-mm depth on the labial surface of bovine incisors. They defined experimental groups (n = 15) according to cavity size, insertion technique (bulk or incremental) and adhesive system applied (Single Bond, 3M ESPE, St. Paul, Minn., or Excite, Ivoclar Vivadent, Amherst, N.Y.). They restored preparations with Tetric Ceram (Ivoclar Vivadent). After 36 hours' storage in distilled water at 37 C, specimens were submitted to microleakage using 50 percent silver nitrate as tracer. Teeth were sectioned twice and dye penetration on the axial wall was determined in millimeters. RESULTS: The authors analyzed the data using analysis of variance/Tukey test (a = .05). For large restorations, the use of Single Bond resulted in higher microleakage than Excite (1.56 +/- standard deviation [SD] 0.26 mm and 0.63 +/- SD 0.56 mm, respectively; P < .001), whereas for small restorations there was no statistical difference between adhesives (Excite: 0.47 +/- SD 0.28 mm; Single Bond: 0.46 +/- SD 0.28 mm). CONCLUSION: The choice of adhesive system influenced microleakage only for large restorations. Incremental insertion of the composite did not affect dye penetration. CLINICAL IMPLICATIONS: Microleakage of composite restorations cannot be predicted only on the basis of the restorations' dimensions. In large restorations, it also depends on the choice of adhesive system, whereas in small restorations, the adhesive used does not seem to be an influential factor. Incremental insertion did not seem to reduce restorations' microleakage.

PMID: 16521386 [PubMed - indexed for MEDLINE]

An investigation into the use of a single component self-etching primer adhesive system for orthodontic bonding: a randomized controlled clinical trial.

J Orthod. 2006 Mar;33(1):38-44; discussion 28

Authors: House K, Ireland AJ, Sherriff M

OBJECTIVE: This study assessed the in vivo bond failure of the single component orthodontic self-etching primer system, Ideal 1 (GAC Orthodontic Products) and compared it with the conventional acid etching using a conventional 37% o-phosphoric acid, rinsing and drying regimen when bonding stainless steel orthodontic brackets to enamel. DESIGN: Prospective randomized, controlled clinical trial. SETTING: Orthodontic Department, Bristol Dental School. MATERIAL AND METHODS: Twenty consecutive patients undergoing upper and lower fixed orthodontic treatment entered this cross-mouth control study. Diagonally opposite quadrants were randomly allocated to either the self-etching primer group or the conventional etching group. A total of 339 teeth were bonded with Ideal 1 light-cured adhesive. Bond failures and locus of bond failure were then recorded at 1, 6 and 12 months. RESULTS: Significantly more bond failures occurred at each of the 3 time intervals, 1, 6 and 12 months, where the enamel was pretreated with the Ideal I self-etching primer, than when the enamel was treated with the conventional etchant, 37% o-phosphoric acid. With the latter the cumulative bond failure rates were 3.0, 5.3 and 14.8%, respectively. With the self-etching primer the cumulative failure rates were 29.4, 56.5 and 72.4%. CONCLUSION: The study found that enamel pre-treatment with the Ideal 1 self-etching primer system prior to orthodontic bonding results in an unacceptably high bond failure rate when compared with conventional enamel acid etching.

PMID: 16514132 [PubMed - indexed for MEDLINE]

Intra-alveolar chlorhexidine gel for the prevention of dry socket in mandibular third molar surgery. A pilot study.

Med Oral Patol Oral Cir Bucal. 2006 Mar;11(2):E179-84

Authors: Torres-Lagares D, Infante-Cossio P, Gutierrez-Perez JL, Romero-Ruiz MM, Garcia-Calderon M, Serrera-Figallo MA

PURPOSE: Chlorhexidine is a good prophylactic agent for post-extraction dry socket alveolitis. The bio-adhesive 0.2% chlorhexidine gel could improve this action since its intra-alveolar positioning would allow a more direct action on the alveolus and more prolonged action of the medication. MATERIALS AND METHOD: We present a single blind, randomised study on 30 patients to evaluate the efficacy of the bio-adhesive 0.2% chlorhexidine gel, placed only once within the alveolus, on the reduction of the incidence of impacted third molar post-extraction dry socket alveolitis and its post-operative effects on patients. RESULTS. A reduction of 42.65% in the occurrence of alveolitis and a more favourable post-operative period in the experimental group was observed. In the control group, the appearance of alveolitis was 30.76% opposite to 17.64 % in the experimental group. CONCLUSIONS: The bio-adhesive 0.2% chlorhexidine gel, applied only once after the extraction of impacted third molars, seems to be an appropriate option for the reduction of alveolitis. It improves the buccal aperture and oedema in the post-operative period, although further double blind studies with larger samples are necessary.

PMID: 16505800 [PubMed - indexed for MEDLINE]