Permanent Dental Restoration Definition Send this page
|Free Full Text References 18 Dec 2007|
Dental trauma: restorative procedures using composite resin and mouthguards f...
Dental trauma: restorative procedures using composite resin and mouthguards for prevention.
J Contemp Dent Pract. 2007;8(6):89-95
Authors: Santos Filho PC, Quagliatto PS, Simamoto PC, Soares CJ
AIM: The aim of this article is to describe a step-by-step protocol for emergency care of a patient with a dentoalveolar injury in the anterior region of the mouth as well as the fabrication of a mouthguard to prevent future trauma. BACKGROUND: Dental trauma is one of the most serious oral health problems in active children and adolescents. Care of traumatized patients requires immediate initial emergency treatment followed by integrated procedures to restore damaged oral structures along with a subsequent trauma prevention strategy. Dentoalveolar injuries in the anterior region of the mouth are often characterized by tooth avulsion and coronal fracture. They are managed using procedures such as dental splinting, endodontic therapy with its unique characteristics, and restorative techniques to re-establish function and esthetics as well as protective mouthguards. REPORT: A 16-year-old male presented with avulsion of his maxillary central incisors as a result of a direct, unintentional impact with an opponent during a basketball game. The teeth had been stored in physiological serum immediately following the injury and the patient received immediate care. On clinical examination, the right central incisor was fractured at the incisal third of the crown but no bone fractures were found. The teeth were reimplanted and splinted. The fractured right central incisor was restored following endodontic treatment and a mouthguard was fabricated for the patient. SUMMARY: The dentist must be knowledgeable about the most efficient and suitable treatment for each traumatic scenario in order to provide appropriate care for dental injuries. Coordinated multi-disciplinary action is fundamental in the successful treatment of these injuries. The dental mouthguard is an effective device for protecting the teeth and supportive structures during physical activities and must be part of the protective equipment used by athletes. It is the responsibility of the dental professional to make parents, trainers, and athletic associations aware of the risks associated with physical activities without orofacial protection; this should encourage the proper use of all protective devices to prevent dentoalveolar injuries that compromise oral functions, esthetics, and increase the cost of healthcare.
PMID: 17846676 [PubMed - indexed for MEDLINE]
Bond strength of composite resin luting cements to fiber-reinforced composite...
Bond strength of composite resin luting cements to fiber-reinforced composite root canal posts.
J Contemp Dent Pract. 2007;8(6):17-24
Authors: Le Bell-Rönnlöf AM, Lahdenperä M, Lassila LV, Vallittu PK
AIMS: The aim of this study was to compare the attachment of different composite resin luting cements to a fiber-reinforced composite (FRC) post with a semi-interpenetrating polymer network polymer matrix. METHODS AND MATERIALS: Six different brands of composite resin luting cement stubs were applied on the surface of FRC post material and light-cured for 40 seconds. Shear bond strengths of luting cement stubs were measured using a universal testing machine. RESULTS: The differences in shear bond strengths between the cements were not statistically significant. CONCLUSION: All of the tested composite resin luting cements provided acceptable attachment to the tested FRC post. The tested FRC post material is suitable to use with different composite resin luting cements.
PMID: 17846667 [PubMed - indexed for MEDLINE]
The influence of temperature on the efficacy of polymerization of composite r...
The influence of temperature on the efficacy of polymerization of composite resin.
J Contemp Dent Pract. 2007;8(6):9-16
Authors: Awliya WY
AIM: The purpose of this study was to investigate the effect of different temperatures on the efficacy of polymerization during the insertion of composite resin using different light curing units. METHODS AND MATERIALS: A total of 45 disc-shaped specimens were fabricated from Z250 composite resin (3M/ESPE, St. Paul, MN, USA) with 15 each prepared at three different temperatures (refrigerated to 5 masculineC, room temperature at 25 masculineC, and preheated to 37 masculineC). Each of these temperature-controlled specimen groups of 15 were then subdivided into three groups of five specimens, according to the type of curing light used to polymerize them. Curing lights included a conventional halogen light (QTH) in two modes (continuous and soft-start polymerization) and a light emitting diode (LED). The microhardness of the top and bottom surfaces of the specimens was determined using a Buehler Micromet II digital microhardness tester (Buehler, Dusseldorf, Germany). Data obtained was analyzed using two-way analysis of variance (ANOVA)/Post Hoc Tukey's test at a 0.05 significance level. RESULTS: As the temperature of composite resin increased, the top and bottom microhardness of the specimens also increased regardless of the type of polymerizing light used. The LED light produced a significantly better hardness on top and bottom surfaces of composite resin specimens polymerized at the three different temperatures. Effectiveness of cure at top and bottom surfaces of composite specimens was significantly reduced by using soft-start curing. CONCLUSION: The use of pre-warmed composite resins might help to improve polymerization of composite resin especially at the deeper areas of a restoration which could result in an increase in the expected life of a composite restoration.
PMID: 17846666 [PubMed - indexed for MEDLINE]
Effect of light curing modes and light curing time on the microhardness of a ...
Effect of light curing modes and light curing time on the microhardness of a hybrid composite resin.
J Contemp Dent Pract. 2007;8(6):1-8
Authors: Aguiar FH, Braceiro A, Lima DA, Ambrosano GM, Lovadino JR
AIMS: The aim of this in vitro study was to evaluate the influence of light curing modes and curing time on the microhardness of a hybrid composite resin. METHODS AND MATERIALS: Forty-five Z250 composite resin specimens (3M-ESPE Dental Products, St. Paul, MN, USA) were randomly divided into nine groups (n=5): three polymerization modes (conventional-550 mW/cm2; light-emitting diodes (LED)-360 mW/cm2, and high intensity-1160 mW/cm2) and three light curing times (once, twice, and three times the manufacturer's recommendations). All samples were polymerized with the light tip 8 mm from the specimen. Knoop microhardness measurements were obtained on the top and bottom surfaces of the sample. RESULTS: Conventional and LED polymerization modes resulted in higher hardness means and were statistically different from the high intensity mode in almost all experimental conditions. Tripling manufacturers' recommended light curing times resulted in higher hardness means; this was statistically different from the other times for all polymerization modes in the bottom surface of specimens. This was also true of the top surface of specimens cured using the high intensity mode but not of conventional and LED modes using any of the chosen curing times. Top surfaces showed higher hardness than bottom surfaces. CONCLUSIONS: It is important to increase the light curing time and use appropriate light curing devices to polymerize resin composite in deep cavities to maximize the hardness of hybrid composite resins.
PMID: 17846665 [PubMed - indexed for MEDLINE]
Analysis of the relationship between the surface hardness and wear resistance...
Analysis of the relationship between the surface hardness and wear resistance of indirect composites used as veneer materials.
Braz Dent J. 2007;18(1):60-4
Authors: Faria AC, Benassi UM, Rodrigues RC, Ribeiro RF, Mattos Mda G
This study evaluated the surface hardness and wear resistance of indirect composites (Artglass and Solidex) and the existence of a correlation between these properties. Twenty-four specimens (12 per material) were fabricated using a polytetrafluoroethylene matrix (5.0 mm in diameter; 7.0 mm high) following an incremental technique. Polymerization was done with a xenon stroboscopic light curing unit. After polishing, the specimens were stored in water at 37 degrees C during either 1 day (n=6 per material) or 55 days (n=6 per material), after which Vickers surface hardness and wear resistance were assessed. Data were analyzed statistically by unpaired Student t-test, two-way ANOVA and Tukey's test. SURFACE HARDNESS: Artglass had higher surface hardness than Solidex after 1-day immersion period (p<0.01), but after 55 days there was no significant difference between the materials (p>0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p<0.01), while no significant difference was found between Solidex means (p>0.05). WEAR RESISTANCE: Solidex had higher wear than Artglass after 1-day immersion period (p<0.01), but no significant difference was found between the materials after 55 days (p>0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p<0.01), with higher wear at 55-day period, but no difference was found between Solidex means (p>0.05). These results suggest that Artglass was better than Solidex in terms of hardness and wear resistance after 1-day water immersion. However, it was more susceptible to degradation, showing greater wear after 55 days. In conclusion, there was an inverse correlation between surface hardness and wear resistance for both Artglass and Solidex indirect composites, that is the higher the hardness, the lower the wear.
PMID: 17639203 [PubMed - indexed for MEDLINE]
Chlorhexidine's effect on sealing ability of composite restorations following...
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]
Three-dimensional surface profile analysis of different types of flowable res...
Three-dimensional surface profile analysis of different types of flowable restorative resins following different finishing protocols.
J Contemp Dent Pract. 2007;8(5):9-17
Authors: Yazici AR, Müftü A, Kugel G
AIM: The aim of this study was to investigate the surface roughness of different types of flowable restorative resins and compare the effectiveness of diamond finishing burs followed by aluminum oxide discs with aluminum oxide discs alone in producing smooth surfaces. METHODS AND MATERIALS: Twenty-four specimens (10 mm X 2 mm) for each flowable resin (flowable microhybrid composite, flowable liquid microhybrid composite, flowable compomer, and flowable ormocer) were fabricated in an acrylic mold and randomly assigned to three groups. In group I samples were left undisturbed after the removal of a Mylar strip (control). In group II samples were polished with diamond finishing burs, followed by aluminum oxide discs. In group III samples were finished with only aluminum oxide discs. The mean surface roughness (Ra, microm) was determined with 3-D non-contact interferometry. Data were subjected to one way analysis of variance (ANOVA), and post hoc comparison was accomplished using Tukey's HSD. RESULTS: Although significant differences in surface roughness (Ra) values were observed among the materials using a Mylar strip (control), no significant differences between restorative materials were found when all finishing/polishing methods were combined. For all flowable restorative resins tested, the Mylar strip produced surfaces smoother than those produced by a diamond finishing bur followed by a disc or by using discs alone. Surface roughness values were statistically similar for a diamond finishing bur followed by a disc and for disc treated surfaces within each material except for Dyract Flow, a flowable compomer. CONCLUSION: Although the surface roughness of flowable restorative resins differs among the types, this difference can be overcome with different finishing/polishing methods.
PMID: 17618325 [PubMed - indexed for MEDLINE]
[Health complaints related to dental filling materials]
[Health complaints related to dental filling materials]
Tidsskr Nor Laegeforen. 2007 May 31;127(11):1524-8
Authors: Lygre GB, Helland V, Gjerdet NR, Björkman L
BACKGROUND: A wide range of materials is used in dental treatment. To what extent these materials lead to adverse reactions is under dispute. The aim of this study was to investigate whether patients with suspected adverse reactions to dental materials experienced an improvement in health after these materials were replaced. MATERIAL AND METHODS: Information on health complaints related to dental materials was obtained from the Dental Biomaterials Adverse Reaction Unit in Bergen, Norway for 142 patients. A follow-up questionnaire regarding subjective health was sent to these patients 1(1/2) to 2(1/2) years later. A similar questionnaire was sent to a reference group of 800 persons drawn from the general population. RESULTS: The patient group had more health complaints than the reference group (p < 0.001) at baseline. Of the 84 patients who completed the questionnaire (59%) 35 had changed dental materials. Amalgam fillings had been replaced in most of these patients. 23 patients (66%) reported improved health after replacement. Intraoral complaints decreased significantly (p = 0.022), and were most pronounced in patients with lesions in contact with dental materials. The intensity of various health complaints decreased slightly in most patients with replaced dental materials, but the patient group still had significantly higher health complaint indices than the reference group. INTERPRETATION: The intensity of subjective health complaints was reduced after replacement of dental materials, but it was still higher than for a comparable group in the general population. The results indicate that there may be a specific health effect of replacing dental materials, but normal symptom fluctuations over time and placebo effects such as positive effects from expectations and general care from the health personnel may have had an influence.
PMID: 17551559 [PubMed - indexed for MEDLINE]
Perceptibility and acceptability of CIELAB color differences in computer-simu...
Perceptibility and acceptability of CIELAB color differences in computer-simulated teeth.
J Dent. 2007 Jul;35(7):593-9
Authors: Lindsey DT, Wee AG
OBJECTIVES: To determine the perceptibility and acceptability of tooth color differences using computer-generated pairs of teeth with simulated gingival displayed on a calibrated color monitor using appropriate signal detection theory methodology (SDT). METHODS: Twelve dental professionals (four from each of the following groups: dentists, dental auxiliaries, and fixed prosthodontic technicians) and four dental patients served as subjects. Responses to tooth color differences (DeltaE) were measured on each of the three principal axes of CIELAB color space (L*, a*, and b*). As a control, responses to DeltaE=0 (the false alarm rate) were also measured in the same experimental session. RESULTS: No group differences among subjects were found. All gave 50% match or acceptance points that averaged about 1.0 DeltaE units in the L* and a* directions, and 2.6 units in the b* direction. False alarm rates across all subjects averaged 27% (4-55%) and 28% (0.4-61%), respectively, for perceptibility and acceptability. A reanalysis of the data based on SDT, which takes subjects' false alarm rates into account, gave somewhat larger color difference thresholds. CONCLUSIONS: Color difference thresholds for our simulated teeth are generally in line with and extend results obtained with studies using "real" dental materials. No differences between thresholds for acceptability versus perceptibility were found. Furthermore, subjects often reported color differences when none existed, and this behavior needs to be factored into any determination of quality control standards for the fabrication of dental prostheses.
PMID: 17517460 [PubMed - indexed for MEDLINE]
Restoration of a vertical tooth fracture and a badly mutilated tooth using ca...
Restoration of a vertical tooth fracture and a badly mutilated tooth using canal projection.
Indian J Dent Res. 2007 Apr-Jun;18(2):87-9
Authors: Velmurugan N, Bhargavi N, Lakshmi N, Kandaswamy D
Management of vertically fractured tooth or a perforation frequently poses problem during endodontic management. Such teeth often need a pre-endodontic restoration prior to initiation of root canal therapy to aid in the placement of rubber dam clamp. This paper describes a simple method of placement of a pre-endodontic restoration using the canal projection technique using hollow metallic needles as sleeves.
PMID: 17502715 [PubMed - indexed for MEDLINE]
Specialty dentistry for the hemophiliac: is there a protocol in place?
Specialty dentistry for the hemophiliac: is there a protocol in place?
Indian J Dent Res. 2007 Apr-Jun;18(2):48-54
Authors: Kumar JN, Kumar RA, Varadarajan R, Sharma N
Restorative dental care for the hemophiliac patient is of paramount importance for the fact that advanced dental conditions and subsequent treatments prove to be more complicated and risky. Quite often, dental health is neglected by hemophiliacs for fear of bleeding during procedures. Surprisingly, even dental specialists avoid these candidates and contribute to the conversion ofa simple dental patient to an oral surgical patient. The complexities involved in diagnosing a bleeding disorder and the rarity of a standardized protocol to handle such patients contribute to this problem. This article prescribes a simple protocol to diagnose bleeding disorders and a modified scheme for endodontic and periodontal therapy in a hemophiliac patient.
PMID: 17502707 [PubMed - indexed for MEDLINE]
Restoring function and esthetics in a patient with amelogenesis imperfecta: a...
Restoring function and esthetics in a patient with amelogenesis imperfecta: a case report.
J Contemp Dent Pract. 2007;8(4):95-101
Authors: Gokce K, Canpolat C, Ozel E
AIM: The purpose of this case report is to present the esthetic and functional rehabilitation of the teeth in a 22-year-old patient with Amelogenesis imperfecta (AI). BACKGROUND: AI is a group of hereditary defects of enamel, unassociated with any other generalized defects. It is a rare developmental abnormality of the enamel, with a variable occurrence of approximately 1:4000 to 1:14000 in Western populations. Al results in poor development or complete absence of the enamel of the teeth caused by improper differentiation of the ameloblasts. REPORT: This report describes the diagnosis and treatment of a young male patient with AI and missing molar teeth using contemporary restorative strategies. Initially, the tooth surfaces were treated with a professional cleaning along with conservative restorative treatment. Later, metal-ceramic crowns for posterior teeth and full-ceramic crowns for anterior teeth were utilized for final restorations. SUMMARY: The complexity of the management of patients with AI supports the suggestion the dental profession should have appropriate methods for the rehabilitation of rare dental disorders. The treatment of patients with AI should start with early diagnosis and intervention to prevent later restorative problems.
PMID: 17486193 [PubMed - indexed for MEDLINE]
Comparative evaluation of the marginal sealing ability of Fuji VII and Concis...
Comparative evaluation of the marginal sealing ability of Fuji VII and Concise as pit and fissure sealants.
J Contemp Dent Pract. 2007;8(4):10-8
Authors: Ganesh M, Shobha T
AIM: The anatomical pits and fissures of the teeth have long been recognized as susceptible areas for the initiation of dental caries. The extreme vulnerability to decay of these pits and fissures on the occlusal surfaces has prompted dental scientists to seek methods of caries prevention. Motivated by the role of pit and fissure sealants in caries prevention, the aim of this study was to compare the efficacy of Fuji VII glass ionomer sealant and Concise resin-based sealant. METHODS AND MATERIALS: An in vitro study was undertaken using forty premolars extracted for orthodontic reasons. The teeth were divided into two groups and sealants were applied. One was an experimental group using Fuji VII as a pit and fissure sealant and the other a control group using Concise. The teeth were kept in gentian violet dye for 24 hours, the sectioned samples were observed for the extent of dye penetration, and scores were based on established scoring criteria. RESULTS: The comparison of the performance of the two groups showed a statistically significant difference. CONCLUSION: The Concise resin-based sealant performed better in terms of sealing ability than did the Fuji VII glass ionomer sealant.
PMID: 17486182 [PubMed - indexed for MEDLINE]
A rational use of dental materials in posterior direct resin restorations in ...
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]
Split-increment technique: an alternative approach for large cervical composi...
Split-increment technique: an alternative approach for large cervical composite resin restorations.
J Contemp Dent Pract. 2007;8(2):121-8
Authors: Hassan KA, Khier SE
AIM: This article proposes and describes the split-increment technique as an alternative for placement of composite resin in large cervical carious lesions which extend onto the root surface. TECHNIQUE: Two flat 1.5 mm thick composite resin increments were used to restore these cervical carious lesions. Prior to light-curing, two diagonal cuts were made in each increment in order to split it into four triangular-shaped flat portions. The first increment was applied to cover the entire axial wall and portions of the four surrounding walls. The second increment was applied to fill the cavity completely covering the first one and the rest of the four surrounding walls as well as sealing all cavity margins. CLINICAL SIGNIFICANCE: This technique results in the reduction of the C-factor and the generated shrinkage stresses by directing the shrinking composite resin during curing towards the free, unbonded areas created by the two diagonal cuts. The proposed technique would also produce a more naturally looking restoration by inserting flat dentin and enamel increments of composite resin of a uniform thickness which closely resembles the arrangement of natural tooth structure.
PMID: 17277835 [PubMed - indexed for MEDLINE]
Effect of centripetal and incremental methods in Class II composite resin res...
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 polycarbon...
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 different finishing and polishing systems on the surface roughn...
The effect of different finishing and polishing systems on the surface roughness of different composite restorative materials.
J Contemp Dent Pract. 2007;8(2):89-96
Authors: Uçtaşli MB, Arisu HD, Omürlü H, Eligüzeloğlu E, Ozcan S, Ergun G
AIM: The purpose of this in vitro study was to examine the effect of two different finishing systems on the surface roughness of different types of composite restorative materials. METHODS AND MATERIALS: Thirty specimens, 8 mm in diameter and 3 mm in depth, were prepared using a microfill composite (Clearfil ST, Kuraray Co. Ltd., Osaka, Japan), a hybrid composite (Clearfil AP-X, Kuraray Co. Ltd., Osaka, Japan), and a packable composite (Clearfil Photo Posterior, Kuraray Co. Ltd., Osaka, Japan) cured against a Mylar matrix strip to create a baseline surface. The average surface roughness was measured using a surface profilometer (Surftest 211, Mitutoyo, Japan) in five different positions on each sample before and after finishing with one of the two finishing systems [Sof-Lex discs (3M) and Po-Go (Dentsply)]. The obtained data were analyzed by two-way analysis of variance (ANOVA) at a p=0.05 significance level. RESULTS: There were statistically significant differences in the average surface roughness (Ra, microm) between the Mylar matrix strip, Sof-Lex discs, and Po-Go discs (p<0.05). For all tested materials, the Mylar matrix strip provided smoother surfaces than both of the finishing systems (p<0.05). When the finishing discs were compared, Sof-Lex discs produced a smoother surface than Po-Go discs for all tested materials (p<0.05). CONCLUSION: The Mylar matrix strip provided a smoother surface than Sof-Lex and Po-Go discs. Furthermore, Sof-Lex discs produced smoother surfaces than Po-Go discs. Sof-Lex and Po-Go systems produced clinically acceptable surface roughness for microfill, hybrid, and packable composite resin materials. The effect of finishing and polishing systems on surface roughness was dependent on both the system and the composite resin restorative material.
PMID: 17277831 [PubMed - indexed for MEDLINE]
Effect of two light-emitting diode (LED) and one halogen curing light on the ...
Effect of two light-emitting diode (LED) and one halogen curing light on the microleakage of Class V flowable composite restorations.
J Contemp Dent Pract. 2007;8(2):80-8
Authors: Attar N, Korkmaz Y
AIM: The disadvantages of light cured composite resin materials with respect to microleakage are predominantly a result of polymerization shrinkage upon curing. It has been shown curing methods play a significant role in polymerization shrinkage of light-cured composite resins. The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with a halogen LCU on microleakage of three different flowable composites using self-etch adhesives. METHODS AND MATERIALS: A total of 63 extracted human premolars were prepared with standardized Class V cavity preparations on the buccal and lingual surfaces of each tooth. The occlusal margin of the cavities was located on the enamel and the gingival margin was on dentin. Teeth were randomly assigned to three groups of 21 teeth each as follows: Group 1: Adper Prompt L-Pop + Filtek Flow (3M ESPE); Group 2: AdheSE + Tetric Flow (Ivoclar, Vivadent); and Group 3: Clearfil Protect Bond + Clearfil Protect Liner F (Kuraray Medical Inc.). All the groups were subdivided into three groups according to the curing lights used (n=7). Two LED LCUs, Elipar FreeLight and Elipar FreeLight 2 (3M ESPE), and one halogen-based LCU, Hilux Expert (Benlioglu ), were used. All teeth were then immersed in 0.5% basic fuchsin dye solution for 24 hours after thermocycling (500 cycles; between 5 degrees C to 55 degrees C). The teeth then were longitudinally sectioned and observed under a stereomicroscope (40X magnification) by two examiners. The degree of dye penetration was recorded separately for enamel and dentin. Data were analyzed with the Kruskal-Wallis and Mann-Whitney tests with the Bonferroni correction. RESULTS: No statistically significant differences in microleakage were observed between groups either on enamel or dentin (p>0.05). CONCLUSION: With the limitation of this in vitro study, the differences in microleakage between LCUs used were not statistically significantly different. Elipar Free Light 2 reduces curing time which can be considered as an advantage.
PMID: 17277830 [PubMed - indexed for MEDLINE]
Effect of photoactivation systems and resin composites on the microleakage of...
Effect of photoactivation systems and resin composites on the microleakage of esthetic restorations.
J Contemp Dent Pract. 2007;8(2):70-9
Authors: Cavalcante LM, Peris AR, Ambrosano GM, Ritter AV, Pimenta LA
AIM: The aim of this study was to evaluate the influence of four photoactivation systems [quartz tungsten halogen (QTH), light-emitting diode (LED), argon ion laser (AL), and plasma arc curing PAC)] on cementum/dentin and enamel microleakage of Class II restorations using a microhybrid [Z250-3M ESPE] and two packable composites [(SureFil-Dentsply and Tetric Ceram HB-Ivoclair/Vivadent]. METHODS AND MATERIALS: Three hundred sixty "vertical-slot Class II cavities" were prepared at the mesial surface of bovine incisors using a 245 carbide bur in a highspeed handpiece. Specimens were divided into twelve groups (composite-photoactivation systems). Half of the specimens had the gingival margin placed in enamel (n=15) and the other half in cementum/dentin (n=15). Composites were inserted and cured in 2 mm increments according to manufacturers' recommended exposure times. After polishing, the samples were immersed in 2% methylene blue solution, sectioned, and evaluated at the gingival margins. Data were submitted to statistical analysis using the Kruskal-Wallis and Mann-Whitney tests. RESULTS: No significant differences were found among the photoactivation systems and among resin composites (p>0.05). Microleakage was not significantly affected by location (enamel vs. cementum/dentin, p>0.05). These findings suggested neither the photoactivation systems nor the resin composite types might have an effect on the microleakage at gingival margins Class II cavities.
PMID: 17277829 [PubMed - indexed for MEDLINE]
Gap formation between different cavity walls and resin composite systems on p...
Gap formation between different cavity walls and resin composite systems on primary and permanent teeth.
J Contemp Dent Pract. 2007;8(2):60-9
Authors: Tulunoglu O, Ulker AE
AIM: The aim of this study was to compare the effectiveness of five self-etching and etch-rinse dentin-bonding agents in achieving a gap-free adaptation between the restorative material and the dentin in primary and permanent teeth. METHODS AND MATERIALS: Gaps located at the restoration dentin interface were evaluated using scanning electron microscopy (SEM). RESULTS: There were more gaps on the corner of the cavities, but no significant difference was detected between different cavity walls (p>0,05). Statistical results of the SEM analysis revealed fewer gaps in the restorations made with self-etching dentin bonding agents than etch-rinse agents at the restoration-dentin interface in both primary and permanent teeth. CONCLUSION: Self-etching bonding systems were preferable in primary and permanent teeth according to the results of this study. However, further studies should be conducted to determine a favorable strategy to eliminate the gaps on the corners of cavities and maintain a gap-free adaptation between resin composite and tooth structure.
PMID: 17277828 [PubMed - indexed for MEDLINE]
Shear bond strength of resin modified glass ionomer cement bonded to differen...
Shear bond strength of resin modified glass ionomer cement bonded to different tooth-colored restorative materials.
J Contemp Dent Pract. 2007;8(2):25-34
Authors: Taher NM, Ateyah NZ
AIM: The aim of this study was to determine in vitro the shear bond strength (MPa) and the type of bond failure when resin-modified glass ionomer cement (RMGIC) was bonded with different tooth-colored restorative materials. METHODS AND MATERIALS: The RMGIC tested was Fuji II LC (FL) and the tooth-colored restorative materials used were composite resin Point-4 (P4), Compomer Dyract AP (DY), and Ormocere Admira (AD). A total number of 60 FL specimens were prepared using Teflon molds. The specimens were divided into six equal groups. Each group of ten specimens was bonded to a tested tooth-colored restorative material as follows: Group I--etched FL bonded to P4; Group II--non-etched FL bonded to P4; Group III--etched FL bonded to DY; Group IV--non-etched FL bonded to DY; Group V--etched FL bonded to AD; and Group VI--non-etched FL bonded to AD. The specimens were stored in distilled water at 37 degrees C for 24 hours. The shear bond strength was measured in a universal testing machine, and the fractured surfaces were examined under a stereomicroscope. RESULTS: The results of the shear bond strength indicated the lowest mean value (14.46 MPa) was in Group III, and this was significantly different from the values of other groups (p<0.05). However, Groups V and VI recorded the highest mean values (24.5 MPa and 28.39 MPa) which were significantly different (p<0.05) when compared to other groups. Groups I, II, and IV showed no significant difference with mean values of 20.06, 19.99, and 20.1 MPa which were significantly different from other groups (p<0.05). CONCLUSION: AD showed the highest shear bond strength to RMGIC. All groups demonstrated a cohesive failure in FL except for Group IV where a cohesive failure in DY was recorded. AD showed good shear bond strength when laminated with FL.
PMID: 17277824 [PubMed - indexed for MEDLINE]
Fatigue strength of fragmented incisal edges restored with a fiber reinforced...
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]
Morphological characterization of the tooth/adhesive interface.
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 adhesiv...
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]
Porcelain laminate veneer restorations bonded with a three-liquid silane bond...
Porcelain laminate veneer restorations bonded with a three-liquid silane bonding agent and a dual-activated luting composite.
J Oral Sci. 2006 Dec;48(4):261-6
Authors: Matsumura H, Aida Y, Ishikawa Y, Tanoue N
This clinical report describes the fabrication and bonding of porcelain laminate veneer restorations in a patient with anterior open spaces. Laminate veneer restorations made of feldspathic porcelain were etched with 5% hydrofluoric acid, rinsed under tap water, ultrasonically cleaned with methanol, and primed with a chemically activated three-liquid silane bonding agent (Clearfil Porcelain Bond). The enamel surfaces were etched with 40% phosphoric acid, rinsed with water, and primed with a two-liquid bonding agent (Clearfil New Bond) that contained a hydrophobic phosphate (10-methacryloyloxydecyl dihydrogen phosphate; MDP). The restorations were bonded with a dual-activated luting composite (Clapearl DC). The veneers have been functioning satisfactorily for an observation period of one year. Combined use of the Clearfil bonding agents and Clapearl DC luting composite is an alternative to conventional materials for seating porcelain laminate veneer restorations, although the system is inapplicable to dentin bonding.
PMID: 17220627 [PubMed - indexed for MEDLINE]
Fracture resistance of various temporary crown materials.
Fracture resistance of various temporary crown materials.
J Contemp Dent Pract. 2007 Jan 1;8(1):44-51
Authors: Yilmaz A, Baydaş S
AIM: The aim of this study was to evaluate the fracture resistance of various provisional crown materials using an in vitro model test system. METHODS AND MATERIALS: In the present study polycarbonate crowns, prefabricated by the manufacturer (3M Polycarbonate Crown), and the temporary crowns, fabricated in the dental laboratory environment, were fabricated using bis-acryl composite (Protemp II), autopolymerizing PMMA resin (BISICO Temp S), and heat-polymerized PMMA resin (Major C&B-V Dentine). All temporary crowns were stored in distilled water for 24 hours at room temperature prior to testing. The crowns were seated on metal dies, fabricated from Cr-Co alloy (AZ Dental, Konstanz, Germany), and then tested using the indenter of a Hounsfield testing machine (Hounsfield Tensometer, Hounsfield Test Equipment, Raydon, England). The tip of the indenter was located at a position one-third of the way down the inciso-palatine surface at 135 masculine. The data were statistically analyzed for differences using one-way analysis of variance (ANOVA) and the Tukey HSD test (P < .05). Additionally, the types of failure obtained from the fracture load test were examined using 10x magnification with a stereo microscope. RESULTS: The results of the present study indicated polycarbonate crowns were significantly different from the BISICO Temp S, Protemp II, and Major C&B-V Dentine (P < .05) groups. CONCLUSION: This in vitro study shows polycarbonate crowns may be preferable to the other types of temporary crowns used in this study.
PMID: 17211504 [PubMed - indexed for MEDLINE]
The effect of finishing and polishing procedures on the surface roughness of ...
The effect of finishing and polishing procedures on the surface roughness of composite resin materials.
J Contemp Dent Pract. 2007 Jan 1;8(1):27-35
Authors: Attar N
AIMS: The aims of this study were to evaluate the effect of various finishing and polishing procedures on the surface roughness of six different composite resin materials (Artemis Enamel, TPH Spectrum, Filtek A-110, Filtek Supreme Enamel, Solitaire 2, and Filtek P-60) as well as to evaluate the effectiveness of the surface sealant application (BisCover) on the surface roughness after finishing and polishing procedures of tested composites. METHODS AND MATERIALS: Specimens (n=168) measuring 5 mm in diameter x 2 mm in thickness were fabricated in a plexiglass well covered with a Mylar strip using six composite resins. A control group of seven specimens of each material received no polishing after being cured under the Mylar strip. Twenty-one specimens for each composite were randomly divided among three finishing and polishing groups (n=7). Each group was polished using a different system: Carbide bur/Sof-Lex disc, Carbide bur/Enhance disc with polishing paste, and Carbide bur/Edenta composite finishing kit. The average surface roughness (Ra, microm) of the control and treated specimens were measured with the Mitutoyo Surftest-402 Surface Roughness tester. After a surface sealant (BisCover) was applied to all treated specimens, according to manufacturer's instructions, the average roughness (Ra) was measured again. Results were statistically analyzed using analysis of variance (ANOVA) and the post-hoc Scheffe's test at a p<0.05 significance level. RESULTS: Significant differences were found for the surface roughness (p<0.05) with interaction among composite resins and the finishing systems used (p<0.05). Enhance/Biscover finishing and polishing procedure surface was not significantly different from the Mylar strip surface groups (p>0.05). The Mylar strip group was not significantly different from the Sof-Lex/BisCover and Edenta/BisCover groups. The ranking of mean Ra values by materials was as follows: Filtek Supreme Enamel < Filtek A110 < TPH Spectrum < Artemis <Filtek P-60 < Solitaire 2. The ranking of mean Ra values by polishing systems was as follows: Enhance/BisCover < Mylar Strip < Sof-Lex/BisCover < Edenta/BisCover < Sof-Lex < Enhance < Edenta. CONCLUSION: Smoother surfaces were recorded for the Enhance/BisCover and the Mylar strip-formed surface groups.The composite finishing kit Edenta significantly increased the Ra for all tested composites (p<0.05). But after finishing with Edenta, the use of a surface sealant (BisCover) significantly improved the surface smoothness of all tested composites (p<0.05). Use of BisCover surface sealant on anterior and posterior resin composite restorations after finishing and polishing procedures is recommended.
PMID: 17211502 [PubMed - indexed for MEDLINE]
Marginal and internal adaptation of commercially pure titanium and titanium-a...
Marginal and internal adaptation of commercially pure titanium and titanium-aluminum-vanadium alloy cast restorations.
J Contemp Dent Pract. 2007 Jan 1;8(1):19-26
Authors: Al Wazzan KA, Al-Nazzawi AA
AIM: The purpose of this in vitro study was to investigate the marginal accuracy and internal fit of complete cast crowns and three-unit fixed partial dentures (FPDs) cast with commercially pure titanium (CPTi) and Titanium-Aluminum-Vanadium alloy (Ti-6Al-4V). METHODS AND MATERIALS: CPTi and Ti-6Al-4V alloy were used to cast twelve single crowns and twelve three-unit FPDs. A traveling microscope was used to measure marginal gap and discrepancies in internal fit. Two and one-way analysis of variance (ANOVA) analyses were used to determine the effects of the marginal and internal fit discrepancies. RESULTS: The Ti-6Al-4V alloy demonstrated a significantly smaller marginal gap than CPTi (P<0.0001). The recorded marginal discrepancies for both metals were within a clinically accepted range (<100 microm). The single crown fit discrepancy was significantly smaller than the three-unit FPD for both the CPTi and the Ti-6Al-4V alloy (P<0.0001). For the internal fit discrepancy, the occlusal surface showed the greatest gaps. CONCLUSIONS: The Ti-6Al-4V alloy demonstrated a better fit than CPTi. Single crowns showed an improved fit when compared with the three-unit FPD. Mid-occlusal internal gap demonstrated greater values than the axial internal gap. CLINICAL IMPLICATIONS: This in vitro study suggested marginal fit of complete crowns and three-unit FPDs cast by CPTi or Ti-6Al-4V alloy were within the range of what is clinically acceptable for longevity of restorations.
PMID: 17211501 [PubMed - indexed for MEDLINE]
[Public school programme for fissure sealants and its effect on the private d...
[Public school programme for fissure sealants and its effect on the private demand for restorative dentistry for temporary teeth]
Aten Primaria. 2006 Nov 30;38(9):496-500
Authors: Prados Atienza MB, Muñoz Soto E, Bravo M, González Rodríguez MP, Prados Sánchez E
OBJECTIVE: To analyse the effect of a public school odontological programme of fissure sealants on the private demand for restorative dentistry for temporary teeth. DESIGN: A longitudinal, comparative study was conducted. It had 2 groups, control and sealant, with 3 years monitoring. SETTING: Santa Fe Health Area, concretely in the local districts (LD) of Santa Fe and Pinos Puente, Granada, Spain, starting in the school year 1996/1997. PARTICIPANTS: The sealant group was selected from the Santa Fe LD (which had a public programme of fissure sealants) (n=129); and the control group (n=120), from Pinos Puente LD. INTERVENTIONS: All the school students were examined (+ report issued) in the schools every 6 months for 3 years. The sealant group children received at the health centre fissure sealants in their first permanent molars. MAIN MEASUREMENTS: The restorations performed in temporary teeth for both groups were analysed (x+/-EE) during the study at 12, 24, and 36 month follow-up. RESULTS. The sealant group had a significantly greater increase in restorative treatment for temporary teeth (P< .05) than the Control group at all monitoring points. CONCLUSIONS: A public programme of fissure sealants raised private restorative treatment for temporary teeth.
PMID: 17194353 [PubMed - indexed for MEDLINE]
A multi-disciplinary approach in the management of a traumatized tooth with c...
A multi-disciplinary approach in the management of a traumatized tooth with complicated crown-root fracture: A case report.
J Indian Soc Pedod Prev Dent. 2006 Dec;24(4):197-200
Authors: Heda CB, Heda AA, Kulkarni SS
A 13-year-old boy had fractured his maxillary right central incisor. The fracture line involved 2/3rd of the crown, compromising the pulp and extended subgingivally on the palatal aspect invading the biologic width. The procedure used to manage this case included endodontic treatment of residual tooth orthodontic extrusion to move the fracture line above the alveolar bone. Finally the tooth was restored prosthodontically.
PMID: 17183184 [PubMed - indexed for MEDLINE]
Eye safety practices in U.S. dental school restorative clinics, 2006.
Eye safety practices in U.S. dental school restorative clinics, 2006.
J Dent Educ. 2006 Dec;70(12):1294-7
Authors: Hill EE
This study was conducted to determine how much progress U.S. dental schools have made in providing eye protection during restorative (adult operative and fixed prosthodontic) procedures since a 1979 survey. A seven-question survey was placed at a website, and fifty-five different U.S. dental schools were asked to complete the survey. Thirty-one schools responded (56 percent). Eighty-four percent of schools had safety glasses available for patients, but only 77 percent required usage during restorative procedures. Similarly, while 87 percent of schools required dental students working in restorative clinics to wear safety glasses, just 73 percent enforced the policy. Additionally, 84 percent provided blue light protection on curing lights and required students to wear eye protection while doing lab procedures. Compared to the 1979 survey, considerable progress has been made over the last twenty-seven years in protecting dental school patients and students from ocular injuries. Because one would hope to have 100 percent compliance on this issue, there is room for improvement in promoting patient eye safety and teaching good habits to dental students.
PMID: 17170319 [PubMed - indexed for MEDLINE]
Are veneers conservative treatment?
Are veneers conservative treatment?
J Am Dent Assoc. 2006 Dec;137(12):1721-3
Authors: Christensen GJ
PMID: 17138718 [PubMed - indexed for MEDLINE]
The radiographic outcomes of direct pulp-capping procedures performed by dent...
The radiographic outcomes of direct pulp-capping procedures performed by dental students: a retrospective study.
J Am Dent Assoc. 2006 Dec;137(12):1699-705
Authors: Al-Hiyasat AS, Barrieshi-Nusair KM, Al-Omari MA
BACKGROUND: The decision between pulp capping and root canal therapy after pulp exposure is a clinical issue. The aim of the authors' study was to evaluate the outcome of direct pulp-capping procedures performed by dental students. METHODS: The authors followed the treatment outcomes of 193 patients with 204 pulp exposures with direct pulp capping. They determined the outcome of pulp capping radiographically using periapical radiographs taken at least three years after pulp exposure. The outcome was considered as successful if the tooth was present and not associated with periapical radiolucency or root canal treatment; otherwise, the outcome was considered as being a failure. RESULTS: Overall, the success rate of pulp capping was 59.3 percent. The success was associated more with mechanical exposure than with carious exposure (92.2 versus 33.3 percent) (P < .001), more with permanent restoration than with temporary restoration (80.8 versus 47.3 percent) (P < .001) and more with class I occlusal restoration (83.8 percent) than with proximal multiple surface restorations (Class II, 56.1 percent; Class III, 58.8 percent; mesial-occlusal-distal, 28.6 percent) (P = .009). Patients' age, sex, and tooth location and position had no significant effect on the outcome (P > .05). CONCLUSION: The success rate of direct pulp capping was 92.2 percent with mechanical exposure and 33.3 percent with carious exposure. CLINICAL IMPLICATIONS: Direct pulp capping is recommended after mechanical exposure with immediate placement of permanent restoration, while root canal therapy would be the choice of treatment if the exposure was due to caries.
PMID: 17138715 [PubMed - indexed for MEDLINE]
Chemomechanical caries removal in children: efficacy and efficiency.
Chemomechanical caries removal in children: efficacy and efficiency.
J Am Dent Assoc. 2006 Dec;137(12):1658-66; quiz 1729-30
Authors: Peters MC, Flamenbaum MH, Eboda NN, Feigal RJ, Inglehart MR
BACKGROUND: The authors investigated the effectiveness of chemomechanical caries removal (CMCR) compared with the traditional method (TM) of caries removal using a round bur when treating dentinal-depth occlusal lesions with minimal enamel access in primary molars. The authors also compare CMCR with TM to determine if it had a higher efficacy and could be used more frequently without the subject's having to undergo local anesthesia. METHODS: The authors collected data from 50 children during operative appointments at which caries was removed using one of the two methods. RESULTS: Complete caries removal within 15 minutes was achieved in only 57.7 percent of the CMCR-treated teeth. In 42.3 percent of these teeth, residual caries was removed using TM. CMCR was almost eight times more time-consuming than was TM when used to excavate dentinal-depth occlusal lesions with minimal cavitation. There was no significant difference between CMCR and TM in the number of subjects who needed to undergo local anesthesia. CONCLUSIONS: The authors found no direct clinical advantage in using CMCR over using TM for treating occlusal dentinal lesions with minimal cavitation in pediatric patients.
PMID: 17138710 [PubMed - indexed for MEDLINE]
A 'commodity-based model'.
A 'commodity-based model'.
J Am Dent Assoc. 2006 Dec;137(12):1639; author reply 1639
Authors: Palo PA
PMID: 17138705 [PubMed - indexed for MEDLINE]
Gingivitis susceptibility and its relation to periodontitis in men.
Gingivitis susceptibility and its relation to periodontitis in men.
J Dent Res. 2006 Dec;85(12):1134-7
Authors: Dietrich T, Kaye EK, Nunn ME, Van Dyke T, Garcia RI
The objective of this cross-sectional study was to evaluate whether gingivitis susceptibility is associated with periodontitis. We analyzed data of 462 men in the VA Dental Longitudinal Study aged 47 to 92 years who had never smoked or had quit smoking 5+ years previously. Multiple logistic regression models, with tooth-level bleeding on probing at sites with attachment loss<or=2 mm as the dependent variable, were derived with adjustment for plaque, calculus, crown coverage, age, income, education, marital status, body mass index, diabetes, and vitamin C intake, and stratification by age (<65, 65+ years). Periodontitis and mean attachment loss were positively associated with bleeding on probing, with stronger associations among men<65 years old (for periodontitis, OR 2.1; 95% CI 1.5, 3.1) than men 65+ years of age (OR 1.2; 95% CI 0.9, 1.6). Our results suggest that among never and former smokers, gingivitis susceptibility is higher among men with periodontitis compared with that in men without periodontitis.
PMID: 17122168 [PubMed - indexed for MEDLINE]
Antagonist enamel wears more than ceramic inlays.
Antagonist enamel wears more than ceramic inlays.
J Dent Res. 2006 Dec;85(12):1097-100
Authors: Krämer N, Kunzelmann KH, Taschner M, Mehl A, Garcia-Godoy F, Frankenberger R
Wear phenomena of ceramic inlays are not fully understood. The aim of the present study was to evaluate ceramic wear, antagonist enamel wear, and luting cement wear over 8 years. The two-fold null hypothesis was that there would be (1) no difference in wear behavior between ceramic and enamel, and (2) no influence of filler content of luting composites on composite wear. From 96 restorations, 36 Class II inlays from 16 participants were selected. For inlays with opposing enamel cusps (n=17), replicas of inlays and enamel were scanned with a 3-D laser scanner. Luting gaps of inlays (n=36) were analyzed with a profilometer, including 3-D data analysis. Ceramic and enamel wear increased between 4 and 8 years, with significantly higher values for enamel after 6 years (p<0.05). Luting gap wear increased continuously up to 8 years (p<0.05), with no influence of luting composites (p>0.05) and location of teeth (p>0.05).
PMID: 17122161 [PubMed - indexed for MEDLINE]
Diametral tensile strength of composite resins submitted to different activat...
Diametral tensile strength of composite resins submitted to different activation techniques.
Braz Oral Res. 2006 Jul-Sep;20(3):214-8
Authors: Casselli DS, Worschech CC, Paulillo LA, Dias CT
The aim of this study was to evaluate the diametral tensile strength (DTS) of composite resins submitted to different curing techniques. Four composite resins were tested in this study: Targis (Ivoclar), Solidex (Shofu), Charisma (Heraeus-Kulzer) and Filtek Z250 (3M Espe). Sixty-four cylindrical specimens were prepared and divided into eight groups according to each polymerization technique (n = 8). The indirect composite resins (Targis and Solidex) were polymerized with their respective curing systems (Targis Power and EDG-lux); Charisma and Filtek Z250 were light-cured with conventional polymerization (halogen light) and additionally, with post-curing systems. Specimens were stored in artificial saliva at 37 degrees C for one week. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). The data were statistically analyzed by ANOVA and Duncan tests. The results were (MPa): Z250/EDG-lux: 69.04 feminine; Z250/Targis Power: 68.57 feminine; Z250/conventional polymerization: 60.75b; Charisma/Targis Power: 52.34c; Charisma/conventional polymerization: 49.17c; Charisma/EDG-lux: 47.98c; Solidex: 36.62d; Targis: 32.86d. The results reveal that the post-cured Z250 composite resin showed the highest DTS means. Charisma composite presented no significant differences when activation techniques were compared. Direct composite resins presented higher DTS values than indirect resins.
PMID: 17119703 [PubMed - indexed for MEDLINE]
Fracture strength of custom-fabricated Celay all-ceramic post and core restor...
Fracture strength of custom-fabricated Celay all-ceramic post and core restored endodontically treated teeth.
Chin Med J (Engl). 2006 Nov 5;119(21):1815-20
Authors: Zhang YX, Zhang WH, Lu ZY, Wang KL
BACKGROUND: The increased use of all-ceramic crown provides a rationale for tooth-colored core. Due to superior mechanical properties, Vita Celay infiltration ceramic developed for crown and bridge works presents the potential for fabricating all-ceramic posts and cores in one piece. This study was conducted to compare the fracture strength of endodontically treated teeth which were thereafter given different types of posts and cores and crowns restoration, respectively. The evaluated post-and-core systems are: custom-fabricated Celay all-ceramic post-core, custom cast metal post-core, and prefabricated stainless steel post (Parapost) with and without 2.0 mm dentine ferrule. METHODS: Sixty freshly extracted human maxillary central incisors were endodontically treated and randomly divided into five groups with 12 samples each. Group A: Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule. Group B: Celay ceramic post-cores restored teeth with no dentine ferrule. Group C: cast metal post-cores restored teeth with 2.0 mm dentine ferrule. Group D: cast metal post-cores restored teeth with no dentine ferrule. Group E: prefabricated post and composite cores restored teeth with 2.0 mm dentine ferrule. All teeth were restored with Celay ceramic crowns. Each specimen was subjected to a load at a 45-degree angle to the long axis on MTS 810 material testing machine until failure, at crosshead speed of 0.02 cm/minute. Analysis of variance followed by the Newman-Keuls pairwise multiple comparison tests were used to compare the results of the groups tested. RESULTS: There was a statistically significant difference among the five groups (P < 0.01). Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule [(758.35+/-19.26) N] and cast metal post-cores restored teeth with 2.0 mm dentine ferrule [(756.63+/-66.22) N] had a significantly greater mean fracture strength than the other three groups in which no significant difference was observed. The 2.0 mm dentine ferrule could cause significant fracture resistance alteration of Celay post-core restored teeth. CONCLUSIONS: When covered with Celay ceramic crowns, Celay post-cores restored teeth with 2.0 mm dentine ferrule and cast metal post-cores restored teeth with 2.0 mm dentine ferrule have similar fracture strength. There was a statistically significant difference between the fracture resistance of Celay post-core restored teeth with and without 2.0 mm dentine ferrule.
PMID: 17097037 [PubMed - indexed for MEDLINE]
Influence of different post core materials on the color of Empress 2 full cer...
Influence of different post core materials on the color of Empress 2 full ceramic crowns.
Chin Med J (Engl). 2006 Oct 20;119(20):1715-20
Authors: Ge J, Wang XZ, Feng HL
BACKGROUND: For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration. METHODS: The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than DeltaE 1.8 between the two ceramic samples. So, DeltaE 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients' satisfaction. RESULTS: When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core (DeltaE = 0.3). The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown (DeltaE = 2.0), but with opaque covering, the color effect became more clinically satisfactory (DeltaE = 1.8). CONCLUSIONS: It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.
PMID: 17097019 [PubMed - indexed for MEDLINE]
Effects of repeated fluoride varnish application on different restorative sur...
Effects of repeated fluoride varnish application on different restorative surfaces.
J Contemp Dent Pract. 2006 Nov 1;7(5):54-61
Authors: Salama FS, Schulte KM, Iseman MF, Reinhardt JW
AIM: The aim of this study was to assess the effect of repeated (twice) applications of two fluoride varnishes (Duraflor and CavityShield) on the surface micromorphology of a high-viscosity glass ionomer (Fuji IX GP), a compomer (F2000), and a flowable composite (Filtek Flow) using a profilometer and scanning electron microscope (SEM). METHODS AND MATERIALS: Fifteen specimens were prepared from each material, surface roughness (Ra) was measured with a profilometer, and an impression was made for epoxy replicas. The fluoride varnishes were applied to the experimental specimens of each material at repeated intervals of 48 hours. For all specimens, Ra was measured and SEM replicas were examined. RESULTS: The final Ra of glass ionomer was 3.49 +/- 0.59 (mean +/- SD) for CavityShield, 4.69 +/- 1.33 for Duraflor, and 2.96 +/- 1.53 for the controls. The final Ra of flowable composite was 0.53 +/- 0.20 for CavityShield, 2.61 +/- 3.08 for Duraflor, and 0.15 +/- 0.09 for controls. For glass ionomer and flowable composite, Duraflor was associated with a significantly higher roughness at the final measurement compared to controls (P < 0.05). SEM micrographs showed differing surface topographies which in many specimens confirmed Ra analysis. CONCLUSION: Fuji IX GP and Filtek Flow showed significantly higher roughness after two applications of Duraflor compared to controls.
PMID: 17091140 [PubMed - indexed for MEDLINE]
One-year clinical evaluation of two resin composites, two polymerization meth...
One-year clinical evaluation of two resin composites, two polymerization methods, and a resin-modified glass ionomer in non-carious cervical lesions.
J Contemp Dent Pract. 2006 Nov 1;7(5):42-53
Authors: Koubi S, Raskin A, Bukiet F, Pignoly C, Toca E, Tassery H
AIM: The aim of this study was to examine clinically relevant data on four restorative procedures for non-carious cervical lesions using United States Public Health Service (USPHS)-compatible clinical and photographic criteria and to compare different methods of analyzing clinical data. METHODS AND MATERIALS: Fourteen patients with at least one or two pairs of non-carious lesions under occlusion and a mean age of 50 were enrolled in this study. A total of 56 restorations (14 with each material) were placed by three experienced, calibrated dental practitioners. Two other experienced and calibrated practitioners, under single-blind conditions, followed up on all restorations for a period of one year. Three materials were randomly placed: a micro-hybrid composite with two polymerization methods (G1 and G2), a flowable micro-hydrid composite (G3), and a resin-modified glass ionomer (G4). Statistical analysis was performed using the Kruskall-Wallis test (p<0.05) and a Mann-Whitney U modified test with a corrected significance level. RESULTS: At the one year evaluation time, there were no restorations with secondary caries and the retention rates in G1 (IntenS with a hard polymerization), G2 (IntenS with a soft polymerization), G3 (Filtek flow), and G4 (Fuji II LC) were 85.7% (two losses), 92.8% (one loss), 100%, and 100%, respectively. The total visual comparison of the results at baseline (15 days later) showed significant differences only with the clinical acceptance criterion: G1 was different from G2, with a soft polymerization device (p<0.05). In terms of surface quality at one year, G1, G2, and G3 exhibited a statistically significant difference from G4, p<0.05. The digital analysis at baseline showed significant differences only with the clinical acceptance criterion: G1=G2 was different from G3=G4, p<0.05. At one year, only the microporosity criterion showed any statistical differences: G1=G2=G3 was different from G4, p<0.05. CONCLUSIONS: The resin-modified glass ionomer was easier to use and had a high retention rate, but it failed in terms of surface quality (visual mode) and porosity (digital mode) criteria compared to the others groups. Overall results showed no difference between groups G1 (hard-polymerized) and G2 (soft-polymerized), and only G1 was affected by the marginal edge (p<0.03) and integrity criteria (p<0.02) at one year.
PMID: 17091139 [PubMed - indexed for MEDLINE]
Effect of the number of coats of simplified adhesive systems on microleakage ...
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.
Microleakage of seven adhesive systems in enamel and dentin.
J Contemp Dent Pract. 2006 Nov 1;7(5):26-33
Authors: Silveira de Araújo 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 compo...
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: Yalçin 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]
Short fiber reinforced composite: the effect of fiber length and volume fract...
Short fiber reinforced composite: the effect of fiber length and volume fraction.
J Contemp Dent Pract. 2006 Nov 1;7(5):10-7
Authors: Garoushi SK, Lassila LV, Vallittu PK
AIM: The aim of this study was to determine the effect of short fiber volume fraction and fiber length on some mechanical properties of short fiber-reinforced composite (FRC). METHODS AND MATERIALS: Test specimens (2 x 2 x 25 mm3) and (9.5 x 5.5 x 3 mm3) were made from short random FRC and prepared with different fiber volumes (0%-22%) and fiber lengths (1-6 mm). Control specimens did not contain fiber reinforcement. The test specimens (n=6) were either dry stored or thermocycled in water (x10.000, 5-55 degrees C) before loading (three-point bending test) according to ISO 10477 or statically loaded with a steel ball (Ø 3.0 mm) with a speed of 1.0 mm/min until fracture. A universal testing machine was used to determine the flexural properties and the load-bearing capacity. Data were analyzed using analysis of variance (ANOVA) (p=0.05) and a linear regression model. RESULTS: The highest flexural strength and fracture load values were registered for specimens with 22 vol% of fibers (330 MPa and 2308 N) and with 5 mm fiber length (281 MPa and 2222 N) in dry conditions. Mechanical properties of all test specimens decreased after thermocycling. ANOVA analysis revealed all factors were affected significantly on the mechanical properties (p<0.001). CONCLUSIONS: By increasing the volume fraction and length of short fibers up to 5 mm, which was the optimum length, the mechanical properties of short FRC were improved.
PMID: 17091135 [PubMed - indexed for MEDLINE]
Is it ethical to report an insurance claim on the preparation date for a crown?
Is it ethical to report an insurance claim on the preparation date for a crown?
J Am Dent Assoc. 2006 Nov;137(11):1597-8
Authors: Smith JF
PMID: 17082287 [PubMed - indexed for MEDLINE]
A clinical evaluation of resin-based composite and glass ionomer cement resto...
A clinical evaluation of resin-based composite and glass ionomer cement restorations placed in primary teeth using the ART approach: results at 24 months.
J Am Dent Assoc. 2006 Nov;137(11):1529-36
Authors: Ersin NK, Candan U, Aykut A, Onçağ O, Eronat C, Kose T
BACKGROUND: The authors evaluated the 24-month performance of a packable resin-based composite/dentin bonding system and a high-viscosity glass ionomer cement (GIC) in restorations placed in primary molars with the atraumatic restorative treatment (ART) approach. METHODS: Three dentists placed 419 restorations in 219 children aged 6 through 10 years who had bilateral matched pairs of carious posterior Class I and II primary teeth. They used a split-mouth design to place the two materials, which were assigned randomly to contralateral sides. The authors evaluated the restorations according to U.S. Public Health Service Ryge criteria. RESULTS: After 24 months, 96.7 percent of the Class I GIC restorations and 91 percent of the resin-based composite restorations survived, while the success rates for the Class II restorations were 76.1 percent and 82 percent for the GIC and resin-based composite restorations, respectively. The survival rate of the Class II resin-based composite restorations was 5.9 percent higher than that of the GIC restorations at the 24-month evaluation, but this difference was not statistically significant. However, the study results showed a statistically significant difference in survival rates between Class I and II restorations for both materials. CONCLUSION AND CLINICAL IMPLICATIONS: The two-year clinical performance of both materials was satisfactory for the restoration of Class I and II primary molars using the ART approach.
PMID: 17082278 [PubMed - indexed for MEDLINE]
A comparative evaluation of four restorative materials to support undermined ...
A comparative evaluation of four restorative materials to support undermined occlusal enamel of permanent teeth.
J Indian Soc Pedod Prev Dent. 2006 Sep;24(3):122-6
Authors: Prabhakar AR, Thejokrishna P, Kurthukoti AJ
The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA), polyacid modified resin composite (F2000 compomer, 3M Dental products, USA.), radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan) and Glass Ionomer cement (Fuji IX GP). To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin supporting the facial cusps was cut away, leaving a shell of enamel. Each group of prepared teeth was restored using the materials according to the manufacturer's instructions. All the specimens were thermocycled (250 cycles, 6 degrees C- 60 degrees C, dwell time 30 seconds) and then mounted on an acrylic base. Specimens were loaded evenly across the cusp tips at a crosshead speed of 5 mm /minute in Hounsfield universal testing machine until fracture occurred. Data obtained was analyzed using analysis of variance and Studentized- Newman- Keul's range test. No significant differences were detected in the support provided by P-60, F 2000, Miracle Mix or Fuji IX GP groups. The support provided to undermined occlusal enamel by these materials was intermediate between no support and that provided by sound dentin. Without further development in dental material technology and evidence of its efficacy, restorative materials should not be relied upon to support undermined occlusal enamel to a level comparable to that provided by sound dentin.
PMID: 17065778 [PubMed - indexed for MEDLINE]