Direct or indirect composite veneers in anterior teeth: which method causes higher tooth mass loss? An in vitro study.

There is little information in the literature regarding the relationship between preparations made for direct and indirect veneers and the loss of tooth structure required for each technique. This in vitro study sought to quantify the different mass losses from preparation techniques used for direct and indirect veneers. Thirty artificial teeth were weighted using a digital balance and placed in a dental manikin in the position corresponding to the right maxillary central incisor. Five clinicians-all experts in esthetic dentistry-were asked to perform conventional preparations for both a direct composite resin veneer and an indirect ceramic veneer. After preparations, specimens were weighted again in the same digital balance. Teeth undergoing veneer preparations demonstrated a statistically significant mass loss compared to unprepared teeth. Indirect ceramic veneer preparations produced more mass loss than direct composite veneer preparations (P < 0.01).

Microtensile bond strength of etch-and-rinse and self-etch adhesives to artificially created carious dentin.

This article evaluates a pH-cycling model for simulation of caries-affected and caries-infected dentin (CAD and CID, respectively) surfaces, by comparing the bond strength of an etch-and-rinse and a self-etch adhesive system. For both adhesives, bonding to sound dentin (SD) showed that the microtensile bond strength (µTBS) values of SD, CAD, and CID were SD > CAD > CID (P < 0.05). Knoop microhardness number mean values followed the same trend. Adhesive systems were not able to totally penetrate into CAD and CID, forming more irregular resin-dentin interdiffusion zones and atypical resin tags than SD. The tested in vitro pH-cycling caries model allowed the evaluation of specific dentin substrate alterations in response to µTBS. The type of dentin and its histological structure played an important role in etch-and-rinse and self-etch bonding, as lower µTBS values were attained in CAD and CID.

Influence of the incorporation of titanium dioxide nanofibers net on bond strength and morphology of a total etching adhesive system.

Background: The aim of this study was to evaluate the nanoleakage and microtensile bond strength (µTBS) of an ethanol based-adhesive containing Titanium dioxide (TiO2) nanofibers to dentin. Material and Methods: TiO2 nanofiber was produced by electrospinning and it was inserted in an ethanol-based adhesive in 0.5, 1.5 and 2.5% by weight. The original adhesive did not receive nanofiber. The middle dentin was exposed by diamond saw under water-cooling and dentin was polished with wet 600-grit SiC abrasive paper. Resin composite build-ups were applied incrementally to the dentin after adhesive application. After storage in distilled water (24 hours/37°C) the teeth were sectioned perpendicularly to the bonded interface and sticks were obtained. Twenty-five sticks per group were tested by µTBS with a crosshead speed of 0.5mm/minute. The average values (MPa) obtained in each substrate were subjected to one-way ANOVA (α=0,05) with the tooth being considered the experimental unit. The nanoleakage pattern was observed in ten sticks per group and analyzed by Chi-square test (α=0,05). Results: There was no difference in µTBS among the experimental groups. However, there was a statistically significant difference among 2.5 % nanofiber adhesive, 0.5 % nanofibers and control groups, (p=0,028) in relation to nanoleakage. Conclusions: TiO2 nanofibers in 2.5% of weight inserted in dental adhesive reduced the nanoleakage, but did not improve the µTBS to dentin. Key words:Dentin-bonding agents, nanoleakage, tensile bond strength.

Spectrophotometric evaluation of restorative composite shades and their match with a classical shade guide.

OBJECTIVES: The aim of this study was to verify the match between 5 shades of composites from different manufacturers with a shade guide and among the systems using a portable spectrophotometer. MATERIALS AND METHODS: Shade measurements were performed on specimens of Z350 XT (3M ESPE), Charisma Diamond (Heraeus Kulzer GmbH), Esthet X-HD (Dentsply Caulk), and Empress Direct (Ivoclar-Vivadent) for shades A1, A2, A3, B1, and C3 using a Vita Easyshade spectrophotometer (Vita Zahnfabrik) against a white background. Corresponding shades of Vitapan Classical (Vita Zahnfabrik) guide were measured likewise and shade variation (ΔE) was calculated based on International Commission on Illumination L*a*b* parameters. The ΔE of the composites in each shade was compared by one-way analysis of variance and Tukey's post hoc test (α = 0.05). RESULTS: All composites presented ΔE > 3.7 compared with the shade guide. Variation in shades A3, B1, and C3 was significantly different for all composites. ΔE of Z350 XT was significantly lower for A1 than for the other shades, whereas ΔE of Z350 XT and Charisma Diamond were significantly lower for A2 than for the other shades. CONCLUSIONS: No composite shade matched with the shade guide. Equivalent shades of the restorative composite from different manufacturers may show clinically noticeable ΔE.

Double-blind randomized clinical trial of posterior composite restorations with or without bevel: 6-month follow-up.

AIM: This double-blind randomized clinical trial compared the performance of posterior composite restorations with and without bevel. METHODS AND MATERIALS: Thirteen volunteers requiring at least two posterior Class II restorations were selected. Twenty-nine cavity preparations were performed, comprising 14 without bevel (butt joint) and 15 with marginal beveling. All cavities were restored with a simplified adhesive system (Adper Single Bond, 3M ESPE, St. Paul, Minnesota, USA) and composite resin (Filtek P60, 3M ESPE, St. Paul, Minnesota, USA). A halogen light-curing unit (XL 3000, 3M ESPE, St. Paul, Minnesota, USA) was used throughout the study. Restorations were polished immediately. Analysis was carried out at baseline and after six months by a calibrated evaluator (kappa), according to FDI criteria. RESULTS: The results were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Beveled and nonbeveled restorations performed similarly after six months in relation to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster, and anatomic form. However, for surface and marginal staining, beveled restorations showed significantly better performance than butt joint restorations (p<0.05). CONCLUSION: Restorations performed were acceptable after six months, but beveled restorations showed less marginal staining than nonbeveled restorations. CLINICAL SIGNIFICANCE: Bevel used in posterior composite restorations decreased the surface and marginal staining, in six-month evaluations.

Influence of restorative technique, beveling, and aging on composite bonding to sectioned incisal edges.

PURPOSE: The aim of this study was to evaluate the effect of material technique, bevel placement, and aging on the fracture resistance of composite restorations bonded to sectioned incisal edges. MATERIALS AND METHODS: For the retention test, the incisal thirds of 80 mandibular human incisors were sectioned. Ten sound incisors were used as a control group. Teeth were divided into two groups according to storage time (24 h and 180 days with 1000 thermal cycles). In each group, subgroups were randomly formed as follows: beveled or nonbeveled direct resin composite restorations (Adper Single Bond/Filtek Z250) and beveled or nonbeveled indirect composite restorations (prepolymerized Filtek Z250 cemented with Adper Single Bond/Rely X ARC). For each experimental group, 20 specimens were prepared (10 tested after 24 h and the remaining after 180 days). The specimens were subjected to shear testing in a universal testing machine with a crosshead speed of 0.5 mm/min. Failure patterns were analyzed by stereomicroscopy (30X). Data were statistically analyzed with ANOVA and Tukey's and Student's t-tests for retention resistance, and with Fisher's exact test for fracture patterns at the 0.05 level of significance for all tests. RESULTS: After 24 h, beveled restorations exhibited higher fracture strength values than nonbeveled restorations and showed resistance similar to the sound teeth. After 6 months, beveled restorations still presented better results than nonbeveled restorations. Thermal cycling and water storage decreased the fracture resistance in the majority of the groups. Adhesive failures were mainly observed in nonbeveled restorations and mixed failures in beveled restorations. CONCLUSION: Within the limitations of the study, it was concluded that storage with thermal cycling decreased fracture resistance, beveling improved fracture resistance, and indirect restorations had a fracture resistance similar to direct restorations.

Fracture resistance and gap formation of MOD restorations: influence of restorative technique, bevel preparation and water storage.

This in vitro study evaluated the effect of technique, use of a bevel and thermal cycling on the fracture resistance and gap formation of resin composite MOD restorations. Fracture resistance was measured on standard MOD cavities prepared in 100 upper premolars that were stored for 24 hours and 6 months with 1000 thermal cycles. Subgroups (n=10) were: beveled or non-beveled preparations and direct restorations (Adper Single Bond/Filtek Z250) and indirect restorations (prepolymerized Filtek Z250 cemented with Rely XARC). Ten sound teeth and 10 specimens with MOD preparations without restorations served as the positive and negative controls, respectively. The specimens were subjected to axial compression in a universal testing machine at a crosshead speed of 0.5 mm/minute. Failure patterns were analyzed by stereomicroscopy (40x). To evaluate gap presence or absence, proximal box cavities were prepared in 24 human third molars that were restored as described above. The specimens were evaluated under SEM examination after 24 hours and six months. Data were statistically analyzed by ANOVA and multiple comparison tests at the 0.05 level of significance. After 24 hours, the beveled restorations exhibited higher fracture strength values than the non-beveled restorations, and all groups showed resistance similar or superior to sound teeth. After six months, the highest fracture resistance was obtained for beveled inlays and the lowest values were observed for direct restorations with butt joints. Thermal cycling decreased fracture resistance in the majority of the groups. The main fracture pattern observed was cohesive failure in the material, but adhesive failures increased over time, especially in the non-beveled restorations. Under SEM examination, no difference was observed among the groups after 24 hours. However, after six months, the beveled restorations exhibited no gap formation. It was concluded that storage with thermal cycling decreased fracture resistance, bevels improved fracture resistance and, in general, indirect restorations were not superior to direct restorations.

Preheated composite resin used as a luting agent for indirect restorations: effects on bond strength and resin-dentin interfaces.

PURPOSE: The aim of this study was to evaluate the effect of preheating composite resins used as luting agents for indirect restorations on microtensile bond strength (µTBS) and adhesive interfaces. MATERIAL AND METHODS: Fifty sound extracted third molars were used. Ten experimental groups were formed with three different luting agents: one resin cement (RelyX ARC) and two composite resins (Venus and Z250 XT). The composite resins were tested both at room temperature and when preheated to 64°C. Restoration depth was tested using 2 or 4 mm-height indirect composite resin restorations, previously made on cylindrical molds. Adhesive and luting procedures were done under simulated pulpal pressure. After luting, the teeth were sectioned into beams with a cross-sectional area of 1 mm2 at the bonded interface, and tested in tension at 0.5 mm/min. The characteristics of the adhesive interfaces were observed under scanning electron microscopy (SEM). The µTBS data were analyzed using ANOVA and the Tukey test (α = 0.05). RESULTS: When luting 2 mm restorations, the composite resin Z250 XT, preheated or at room temperature, achieved significantly higher µTBS than did RelyX ARC. At this depth, Venus did not differ from the resin cement, and with the 4 mm restorations, only preheated Venus presented significantly higher µTBS than RelyX ARC. Preheating the composite resin resulted in thinner luting interfaces, with a more intimate interaction between luting agent and adhesive layer. CONCLUSION: Preheating composite resin for luting procedures may not improve µTBS, although it could be used to reduce material viscosity and improve restoration setting.

Sleep bruxism: challenges and restorative solutions.

Bruxism is a parafunctional activity related to clenching or grinding the teeth and tooth wear can be a consequence of sleep bruxism (SB). Management of severe tooth wear due to SB is a challenging situation because of the common reduced amount of remaining dental structure and loss of vertical dimension of occlusion. Rationale for the planning of oral rehabilitation of patients with SB presenting severe tooth wear should rely on evidence-based approaches; however, few studies have discussed properties of dental materials for SB rehabilitation and how to cosmetically manage severe tooth wear. This review aimed to provide an overview into bruxism cosmetic rehabilitation and how this can be implemented with good outcomes for the patient.

Direct anterior composite veneers in vital and non-vital teeth: a retrospective clinical evaluation.

OBJECTIVES: This retrospective, longitudinal clinical study investigated the performance of direct veneers using different composites (microfilled×universal) in vital or non-vital anterior teeth. METHODS: Records from 86 patients were retrieved from a Dental School clinic, comprising 196 direct veneers to be evaluated. The FDI criteria were used to assess the clinical evaluation. The survival analysis was done using Kaplan-Meier method and Log-Rank test. The multivariate Cox regression with shared frailty was used to investigate the factors associated with failure. RESULTS: A total of 196 veneers were evaluated, with 39 failures. The mean time of service for the veneers was 3.5 years, with a general survival rate of 80.1%. In the qualitative evaluation of the restorations, microfilled composite showed slighty better esthetics. The annual failure rates (AFR) were 4.9% for veneers in vital teeth and 9.8% for non-vital teeth with statistical significance (p=0.009). For microfilled and universal veneers the respective AFRs were 6.0% and 6.2% (p>0.05). Veneers made in non-vital teeth had a higher risk of failure over time compared to those made in vital teeth (HR 2.78; 95% CI 1.02-7.56), but the type of material was not a significant factor (p=0.991). The main reason for failure was fracture of the veneer. CONCLUSION: Direct composite veneers showed a satisfactory clinical performance. Veneers performed in vital teeth showed a better performance than those placed in non-vital teeth. No difference in the survival rate for different composites was found, although microfilled composites showed a slightly better esthetic appearance. CLINICAL SIGNIFICANCE: Direct composite veneers show good results in esthetic dentistry nowadays. Composite veneers in vital teeth have a lower risk of failure than those in non-vital teeth.

A clinical evaluation of direct veneers made with two types of composites

Objectives: the aim of this study was to provide a retrospective clinical evaluation of direct composite veneers performed with microfilled or universal composites, through two evaluation criteria (FDI and USPHS). Materials and methods: patients should be in compliance with the inclusion criteria: having a composite veneer in anterior teeth made either with microfilled or universal using composites (microhybrid/nanohybrid), conventional dentin-bonding agents and for a minimum of 6 months period in service. A calibrated blind examiner assessed the veneers using the FDI and USPHS criteria and the results were subjected to statistical analysis by the Mann-Whitney test (p<0.05). Results: Twenty-eight patients (mean age 42.9 year-old) and seventy-four composite veneers were examined. The mean period of time in service was three years, with periods varying from six months up to ten years. Three cases of total failure (veneers lost, universal composites group) occurred in the surveyed patients, out of 17 failures in total. In general, the veneers showed a clinical satisfactory outcome (77% survival rate). Concerning the two composite types, better clinical performance was observed for microfilled in relation to surface luster, surface staining, colour match and marginal adaptation. Conclusion: In this interim evaluation, direct composite veneers demonstrated an acceptable clinical behavior. Microfilled composite veneers showed a better performance compared to universal composites. The two criteria (USPHS and FDI) were similar in the clinical evaluation process. Clinical relevance: direct composite veneers have a good clinical performance, microfilled composites are interesting options regarding esthetic properties.

A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-year follow-up.

OBJECTIVE: This randomized double-blind clinical trial compared the performance of posterior composite restorations with or without bevel, after 1-year follow-up. MATERIAL AND METHODS: Thirteen volunteers requiring at least two posterior composite restorations were selected. Twenty-nine cavities were performed, comprising 14 without bevel (butt joint) and 15 with bevel preparation of the enamel cavosurface angle. All cavities were restored with simplified adhesive system (Adper Single Bond) and composite resin (Filtek P60). A halogen light curing unit was used through the study. Restorations were polished immediately. Analysis was carried out at baseline, after 6 months and after 1 year by a calibrated evaluator (Kappa), according to the FDI criteria. Data were statistically analyzed by Mann-Whitney test (p <0.05). RESULTS: Beveled and non-beveled cavities performed similarly after 1 year follow-up, regarding to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster and anatomic form. However, for surface and marginal staining, beveled cavities showed significantly better performance (p<0.05) than butt joint restorations. CONCLUSIONS: It was concluded that the restorations were acceptable after 1 year, but restorations placed in cavities with marginal beveling showed less marginal staining than those placed in non-beveled cavities.

Effect of cariogenic biofilm challenge on the surface hardness of direct restorative materials in situ.

OBJECTIVES: The presence of cariogenic biofilm could result in surface degradation of composite and ionomeric restorative materials. Thus, this study evaluated in situ the alterations in the surface microhardness of these materials under biofilm accumulation and cariogenic challenge. METHODS: In a split-mouth, double-blind, cross-over study, 10 volunteers wore palatal intra-oral devices containing bovine enamel slabs restored with composite resin (CR - Z250) or resin-modified glass ionomer (RMGI - Vitremer). Two phases of 14 days were carried out, one for each restorative material. In one side of the device, biofilm was allowed to accumulate under a plastic mesh, whereas in the opposing side, regular brushing was carried out 3 times/day with a dentifrice containing 1100 µg F/g as NaF. A 20% sucrose solution was applied extra-orally 10×/day on each restored dental slab. Knoop microhardness was used to calculate the percentage of surface hardness loss (%SHL). RESULTS: All materials showed a decrease in surface hardness after the in situ period. The restorative materials presented the following average for %SHL: RMGI without biofilm accumulation=8.9 and with biofilm accumulation=25.6, CR without biofilm accumulation=14.7 and with biofilm accumulation=17.0. CONCLUSION: Biofilm accumulation and the presence of cariogenic challenge promoted faster degradation of ionomeric materials, but this was not observed for composite resin. CLINICAL SIGNIFICANCE: The oral environment affects the surface hardness of aesthetic restorative materials. Biofilm accumulation and cariogenic challenge promote surface degradation for ionomeric materials, but not for composite resin.

Influence of adhesive system and bevel preparation on fracture strength of teeth restored with composite resin.

The aim of this study was to evaluate the fracture strength of teeth with different cavosurface margin cavity preparations and restored with composite resin and different adhesive systems. Eighty premolars were randomly divided in 8 groups, as follow: G1- sound teeth; G2- MOD preparation (no restoration); G3- Adper Single Bond without bevel preparation (butt joint); G4- Adper Single Bond with bevel preparation; G5- Adper Single Bond with chamfer preparation; G6- Clearfil SE Bond without bevel (butt joint); G7- Clearfil SE Bond with bevel preparation; G8- Clearfil SE Bond with chamfer preparation. The adhesive systems were applied according to manufacturers' instructions. Composite resin (Filtek Z250) was incrementally placed in all cavities. After 24 h, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (fracture strength) and Fisher's exact test (fracture pattern). The confidence level was set at 95% for all tests. Prepared and non-restored teeth showed the worst performance and G4 exhibited the highest fracture strength among all groups (p<0.05). In conclusion, all restorative treatments were able to recover the fracture strength of non-restored teeth to levels similar to those of sound teeth. Using a total-etch adhesive system with bevel preparation significantly improved the resistance to fracture.

Avaliacão clínica de restauracões de resina composta em molares decíduos estudo piloto / A clinical evaluation of composite restorations in primary molars - an interim study

As restaurações de resina composta têm sido amplamente utilizadas na Clínica Infantil, pois além de preservarem a estrutura dental sadia são mais estéticas e o seu desgaste é semelhante ao desgaste fisiológico do dente decíduo. Objetivos: avaliar o comportamento e a longevidade das restaurações realizadas com resina composta em dentes decíduos posteriores utilizando os métodos USPHS e FDI. Materiais e Métodos: foram selecionadas 09 crianças que possuíam 34 restaurações eclusas ou ocluso-proximal em molares decíduos, realizadas no curso de graduação da Universidade Luterana do Brasil Cachoeira do Sul/RS com as resinas Charisma®, Filtekl P60, Filtekl Z250 XT. As restaurações foram avaliadas por um examinador cego para os objetivos do estudo, segundo critérios dos métodos USPHS e FOI. A análise estatística foi realizada com o teste Kruskal-Wallis, com nível de significãncia 5%. Resultados: as 34 restaurações feitas com as três resinas compostas não apresentaram diferenças em relação à maioria dos critérios nos dois métodos empregados. Apenas para o critério manchamento superficial houve diferença entre as resinas compostas (p=0,006), sendo que a resina Filtek P60 demonstrou maior manchamento superficial do que as resinas Charisma e Filtek Z250. Conclusões: as três resinas compostas mostraram-se satisfatórias durante o período de tempo avaliado, confirmando a sua indicação para tratamentos restauradores dos dentes decíduos. As resinas Charisma e Filtek Z250 apresentaram melhor desempenho em relação ao manchamento superficial do que a Filtek P60. Os dois métodos de avaliação clínica podem ser utilizados para avaliação de restaurações em dentes decíduos, sendo o método FDI mais completo e promissor.

The composite resins have been widely used in Pediatric Dentistry, because they preserve the health dental structure, are more esthetics and their abrasion levei is similar that of the deciduous teeth. Objectives: to evaluate the behavior and the longevity of the composite resins fillings in posterior deciduous teeth using the USPHS and FDI methods. Materiais and methods: 09 children were selected who had 34 restorations (occlusal and occlusoproximal) in primary molars performed by undergraduate students of Lutheran University of Brazil Cachoeira do Sul/RS with Charisma®, Filtekl P60, Filtekl Z250 XT composite resins). The restorations were evaluated by an examiner blinded to the study objectives, through USPHS and FDI methods criteria. Statistical analysis was performed by the Kruskal-Wallis test, with the significance level set at 5%. Results: the 3 composite resins did not show any difference regarding to majority of criteria employed in the two methods. For the superficial staining criterion there was statistically significant difference among the composite resins (p=0,OO6), being Filtek P60 the resin that showed worst superficial staining than Charisma and Filtek Z250. Conclusions: the composite resins evaluated were satisfactory and available to fill deciduous teeth. lhe composite resins Charisma and Filtek Z250 showed better performance than Filtek P60 in relation to superficial staining criterion. The two evaluation methods can be used to evaluate restorative procedures in deciduous teeth, being FOI method the most complete and promising though.

Pulpotomy in deciduous tooth with mineral trioxid aggregate / Pulpotomia em molar decíduo com agregado trióxido mineral

Several medicines have been tested and used in the conservative pulp therapy of deciduous teeth, however, the formocresol has being the elected material in the pulpotomies, even not assisting the biocompatibility demands and promoting the fixation of the vital pulp tissue and not its repair. After Mineral Trioxide Aggregate (MTA) appearance as a material with physico-chemical properties that promotes the tissue repair, allied to other important properties, such as the antimicrobial action and the biocompatibility to the pulpal tissues, a new alternative material appeared for the dentistry. The aim of this study was to report the effect of MTA in a pulpotomy of deciduous molar, and its 1-year follow-up. The pulpotomy was made with MTA in the tooth 85 in a 5-year-old patient. The results obtained were quite favorable, demonstrating clinical and radiographic success, as well as absence of painful symptomatology reported by the patient. In spite of the little time of follow-up of the treated deciduous tooth, MTA has a great biological potential and could be an alternative material to be used in the pulpotomies of deciduous teeth.

Diversos medicamentos vêm sendo testados e utilizados na terapia pulpar conservadora de dentes decíduos, no entanto, o formocresol continua sendo o material de escolha nas pulpotomias, mesmo não atendendo às exigências de biocompatibilidade e promovendo a fixação do tecido pulpar vital e não o seu reparo. Com o surgimento do Agregado Trióxido Mineral (MTA) como um material com propriedades físico-químicas que promovem o reparo tecidual, aliados a outras propriedades importantes, tais como a ação antimicrobiana e a biocompatibilidade aos tecidos pulpares surgiu uma nova alternativa de material na Odontologia. O objetivo deste estudo foi relatar o desempenho do MTA em uma pulpotomia em molar decíduo e seu acompanhamento por um período de 1 ano. Foi realizada a pulpotomia com o uso do MTA no dente 85 de um paciente de 5 anos de idade cujos resultados obtidos foram bastante favoráveis, demonstrando sucesso clínico e radiográfico no período avaliado. Apesar do pouco tempo de acompanhamento do dente decíduo tratado, acredita-se que o MTA possa ter um grande potencial biológico e futuramente podendo transformar-se em uma opção de material para ser utilizado como rotina nas pulpotomias de dentes decíduos.

Avaliação clínica retrospectiva de restaurações proximais de resina composta de classes III e IV / Retrospective clinical evaluation of proximal composite resin restorations (class III and IV)

A resina composta é frequentemente utilizada na saú- de pública, sendo um dos principais materiais usados na atenção primária. Um estudo de avaliação retrospectiva reflete uma real situação dos procedimentos restauradores. Objetivo: Realizar uma avaliação clínica retrospectiva de restaurações diretas proximais de resinas compostas em dentes anteriores (classes III e IV) realizadas na Faculdade de Odontologia da Universidade Federal do Rio Grande do Sul. Métodos: De acordo com os critérios de inclusão e exclusão, dois métodos de avaliação foram utilizados por um examinador calibrado e cego, o USPHS e o FDI modificados. Resultados: Foram avaliadas 79 restaurações, feitas de há 6 meses até há 20 anos. As restaurações proximais foram divididas em dois grupos, classe III (n = 33) e classe IV (n = 46). Na classe III, oito delas foram classificadas como clinicamente insatisfatórias em pelo menos um dos métodos de avaliação clínica (24%). Já na classe IV, nove delas se apresentaram como insuficientes (20%). As maiores causas de falha para a classe III foram: manchamento marginal (12%) e adaptação marginal (12%) pelo FDI, integridade marginal (9%) e cárie secundária (9%) pelo USPHS; e para classe IV: fraturas e retenção (11%) pelo FDI, forma anatômica (9%) e fraturas e retenção (9%) pelo USPHS. Conclusão: Restaurações de resina composta demonstraram um desempenho clínico satisfatório ao longo do tempo, apresentando uma baixa taxa de falha no período avaliado. Os dois métodos (USPHS e FDI) se mostraram eficazes no processo de avaliação clínica...

Influence of filling technique and bevel preparation on marginal sealing of conventional and low shrinkage composite restorations

AIM: The aim of this study was to evaluate two composite restorations (conventional methacrylate-based and low shrinkage-based silorane), associated or not to beveling and incremental technique, in relation to the microleakage and marginal gap formation tests. MATERIAL AND METHODS: 30 sound human molars had their mesial and distal surfaces prepared with and without bevel. The teeth were divided into six groups according to the type of resin (conventional nanofilled or silorane resin), and restorative filling technique (incremental technique or builk). Microleakage and marginal gap formation data were statistically analyzed by Kruskal-Wallis and Chi-Square tests, with a significance level set at 5%. RESULTS: Group 1 (Z350 XT, without bevel, incremental technique) presented highest rate of microleakage and marginal gap in most of the restorations, with statistically significant differences. Groups 4 and 6 (P90, beveled, builk and P90, beveled and incremental technique) had lower rates of microleakage and absence of marginal gaps in most of the restorations. CONCLUSION: It's concluded that the silorane showed lower rates of marginal gaps and microleakage, when compared to the conventional methacrylate-based resin. Bevel preparation was effective in reducing microleakage and marginal gaps for both resins used. Incremental technique was not necessary when associated with low shrinkage composite resin.

Quantitative and qualitative evaluation of resin-dentin bond strengths: in vitro effects of surface treatment with metalloproteinase inhibitors

AIM: The objective of this study was to evaluate the use of MMPs inhibitors (chlorhexidine and EDTA) in bond strength and quality of the hybrid layer of adhesive restorations in normal dentin using two ethanol-based total-etch adhesive systems. MATERIAL AND METHODS: Thirty-two extracted human molars were coronally sectioned and randomly divided into 8 groups (n=4), depending on the surface pre-treatment and adhesive system used. The total-etch adhesive systems Single Bond 2 (2-step) and Adper Scotchbond Multi-Purpose Plus (3-step) were used as follows: 1) according to manufacturer's instructions (etching with 37% phosphoric acid (H3PO4) for 15 s); 2) etching with H3PO4 for 15 s, followed by 2% chlorhexidine for 120 s; 3) etching with 0.1 M EDTA for 60 s; 4) etching with 0.1 M EDTA followed by 2% chlorhexidine for 120 s. Teeth were incrementally restored with composite resin (Filtek Z350XT). After water storage for 24 h, teeth were double-sectioned, yielding stick specimens of 1.0 mm² bonded area, and then subjected to microtensile bond strength (MTBS) test at 0.5 mm/min. Additional specimens were gold-sputtered to be analyzed under scanning electron microscopy (SEM). Data (in Mega Pascal) were subjected to Kruskal-Wallis and Dunn (p <0.05) tests. RESULTS: The etching protocol (37% H3PO4 or EDTA) interfered with hybrid layer formation, monomer penetration and the MTBS. Funnel shaped resin tags were observed when dentin was etched with 37% H3PO4. In these specimens, MTBS were also higher. EDTA conditioning produced thin hybrid layers and smaller MTBS, regardless the adhesive system used. Chlorhexidine application after conditioning resulted in no apparent differences between both evaluated techniques (37% H3PO4 or EDTA). CONCLUSION: The use of chlorhexidine as a MMP inhibitor does not alter immediate bond strength values and does not interfere with hybrid layer formation.

Clareamento de dentes tratados endodonticamente: uma revisão da literatura / Bleaching of root-filled teeth: a literature review

Na Odontologia contemporânea, a estética sofreu uma valorizaçãosignificativa, ganhando destaque e importância. Nesse contexto, a belezaé influenciada pelo contorno, forma, simetria, alinhamento e,principalmente, pela cor dos dentes. O clareamento de dentes anterioresdesvitalizados escurecidos tem se tornado uma terapia muito requisitada,uma vez que o escurecimento dos dentes é motivo de grande insatisfaçãopor parte dos pacientes. Esta revisão de literatura tem como objetivoanalisar os dados disponíveis na literatura sobre este assunto, uma vezque a associação entre o clareamento interno e a reabsorção radicularexterna cervical é uma questão que ainda gera dúvidas na práticaodontológica. O clareamento interno apresenta resultados esteticamentesatisfatórios, no entanto, apresenta como possível efeito colateral areabsorção radicular cervical externa, que prejudica ou até mesmoinviabiliza a permanência do elemento dental na cavidade bucal. Aetiologia da reabsorção radicular externa relacionada ao clareamento écomplexa, no entanto acredita-se que o agente clareador alcance ostecidos periodontais através dos túbulos dentinários, desnature a dentina,que passa a ser considerada um tecido imunologicamente diferente,sendo reconhecida como um corpo estranho e inicia uma reaçãoinflamatória que resulta na perda localizada de tecido dental. Outralimitação do clareamento de dentes tratados endodonticamente é arecidiva da cor, ainda pouco compreendida. Apesar do clareamento dedentes desvitalizados ter um alto índice de sucesso e de sua naturezaminimamente invasiva, os possíveis efeitos colaterais, tais como areabsorção cervical externa e a recidiva de cor devem ser levados emconsideração no momento de sua indicação.

In modern Dentistry, the smile aesthetics is more valuable every day,gaining importance and prominence. In this context, the beauty isinfluenced by contour, shape, alignment, symmetry and, specially, thecolor of the teeth. The bleaching of anterior endodontically treateddarkened teeth has become a therapy very requested in the clinicalpractice of Dentistry, because stained teeth is of great concern forpatients. This literature review has as objective to analyze the availabledata on this subject, since the association between internal bleaching andexternal cervical root resorption is an issue that still raises questions indental practice. The internal bleaching has aesthetic success, however,this procedure is associated with a risk of external root resorption, whichhinders or even makes impossible the maintenance of the tooth in the oralcavity. The etiology of the external root resorption related to the internalbleaching is complex, however it’s believed that the bleaching chemicalsdiffuse from the pulp chamber through patent dentinal tubules to thesurrounding periodontal tissues, denatures dentin, which starts to beconsidered as a tissue with immunological differences, starting, then, to berecognized as a strange body, resulting in an inflammatory reaction whichresults, then, in the located loss of tissue. Another limitation of the internalbleaching of root-filled teeth is the discoloration. In spite of this procedure’shigh success rate, the results are different from those seen at long-termfollow-up, that is, the color regression is a fact that must be studied andbetter understood.