Three-year follow-up of flowable bulk-fill resin restorations in posterior teeth: a double-blind randomized controlled clinical trial / Acompanhamento de três anos de restaurações do tipo bulk-fill flow em dentes posteriores: ensaio clínico controlado randomizado duplo-cego

Objetivo: Este ensaio clínico randomizado avaliou o comportamento de restaurações com resina composta bulk-fill flow em dentes posteriores após três anos do tratamento restaurador. Métodos: Dezessete pacientes (12 mulheres, 5 homens, idade 23-59) foram selecionados para ter pelo menos duas restaurações de amálgama ou de resina composta substituídas, ou receber tratamento restaurador para lesão cariosa. As cavidades foram aleatoriamente alocadas para receberem o compósito bulk-fill flow Suferil SDR Flow, oclusamente coberto por uma resina composta convencional nano-híbrida Esthet-X HD (técnica bulk and body), ou serem preenchidas exclusivamente com Esthet-X HD, inseridas em incrementos de 2mm cada técnica incremental). Um adesivo convencional de dois passos foi aplicado em todas as cavidades. Trinta e quatro restaurações Classes I ou II foram realizados em dentes posteriores (n=17) no início do estudo (baseline). Após 03 anos, os critérios do USPHS modificado e FDI foram utilizados para avaliar as restaurações. Os dados foram submetidos à análise estatística Mann-Whitney (p<0,05). Resultados: No acompanhamento de 3 anos, vinte e quatro restaurações (17 Classes I e 7 Classes II) foram avaliadas. Não foram detectadas diferenças entre as técnicas restauradoras (p>0,05). Não houve falha em nenhuma restauração ao longo do tempo. Conclusão: Após 03 anos de serviço clínico, todas restaurações utilizando um compósito bulk-fill flow em dentes posteriores demonstraram uma performance satisfatória. Significância Clínica: A qualidade geral das restaurações em dentes posteriores realizadas com a técnica bulk and body foi similar ao das restaurações incrementais utilizando um compósito nano-híbrido. (AU)

Objective: This randomized clinical trial evaluated the behavior of restorations with flowable bulk-fill resin composite in posterior teeth three years after the restorative treatment. Methods: Seventeen patients (12 women, 5 men, age 23-59) were selected to have at least two failing amalgam or resin restorations replaced and/or to have a carious lesion restored. The cavities were randomly allocated to receive either the flowable bulk-fill composite Surefil SDR Flow occlusally covered with the conventional nano-hybrid composite Esthet-X HD (bulk and body technique) or filled exclusively with Esthet-X HD placed in 2 mm increments (incremental technique). A two-step etch-and-rinse adhesive was applied in all cavities. Thirty-four Class I or II restorations were performed in posterior teeth (n=17) during baseline. After 03 years, modified USPHS and FDI criteria were used to evaluate the restorations. Data were subjected to Mann-Whitney statistical analysis (p<0.05). Results: At the 3-year follow-up, twenty-four restorations (17 Class I and 7 Class II) were evaluated. No diff erences were detected between the bulk and body and the incremental restorations (p>0.05). No restoration failures were observed over time. Conclusion: After 03 years of clinical service, all restorations using a flowable bulk-fill composite in posterior teeth showed an acceptable performance. Clinical Significance: The overall quality of posterior restorations made with the bulk and body technique was similar to that of restorations made with a nano-hybrid composite incrementally placed. (AU)

Microshear Bond Strength of Adhesive Systems on Eroded Primary Enamel and Dentin.

Purpose: Erosive tooth wear often leads to surface loss requiring restoration of primary teeth with adhesive materials. The purpose of this study was to evaluate the microshear bond strength (µSBS) of different adhesive systems to sound and eroded primary enamel and dentin surfaces. Methods: Half of the samples underwent erosion (immersion in Coca-Cola for one minute five times over five days) and abrasion cycles (brushing with an electric toothbrush, fluoride toothpaste slurry, for one minute at 250 g load). Samples were divided into adhesive groups (n equals 12): Adper Single Bond 2 (etch-and-rinse); Single Bond Universal (self-etch); Optibond FL (etch-and-rinse with fluoride); and Bond-Force (self-etch with fluoride). Resin composite was bonded on sample surfaces and subjected to µSBS test. Data were analyzed by two-way analysis of variance, Tukey test, and chi-square test (P<0.05). The failure mode was determined using a stereomicroscope under 20X magnification. Results: No difference was found between the eroded and sound enamel and dentin (P≥ 0.05) on µSBS test. The failure mode evaluation showed significant differences between sound and eroded dentin (P=0.003) but no difference among the adhesives (P=0.177). Conclusions: Micro-shear bond strength in primary enamel and dentin was not affected by erosion/abrasion or type of adhesive system.

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.

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study.

To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 µm, 50 µm, and 100 µm from the eroded surface and at 25 µm, 75 µm, and 125 µm from the enamel bond interface. Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

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.

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study

ABSTRACT Objective: To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Material and Methods: Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Results: Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). Conclusions: We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

Fechamento de diastema com resina composta direta: relato de caso clínico / Diastema closure with direct composite restorations: a case report

Com a evolução dos materiais restauradores adesivos diretos e das técnicas restauradoras minimamente invasivas, é possível realizar o fechamento de diastemas inter incisivos superiores de maneira efetiva e estética em uma única sessão. O presente trabalho consiste em um relato de caso clínico que aborda o clareamento dental e o fechamento de diastema entre os dentes 11 e 21 de um paciente jovem. Previamente ao procedimento restaurador foi realizado clareamento de consultório em todos os dentes com peróxido de hidrogênio 35%. Então, o planejamento restaurador foi auxiliado por modelos de estudo associado ao enceramento diagnóstico.A técnica restauradora de eleição foi a resina composta direta com o auxílio de uma matriz/guia de silicona para a confecção das faces palatinas das restaurações. Após o acabamento e polimento, obteve-se a reanatomização dos incisivos centrais com a eliminação do diastema. O tratamento realizado baseado no clareamento dental seguido por restaurações diretas de resina composta foi eficaz na solução estética do sorriso, atingindo a expectativa do paciente e dentro dos princípios de máxima preservação dos tecidos dentais.

After the evolution of restorative adhesive materials and minimal invasive restorations, it ispossible to close a maxilar interincisal diastema in an effective and aesthetical way, performingit in only one session. This clinical case report approaches a teeth bleaching and diastema closurewith composites between teeth 11 and 21, of a young male patient. The elective restorative technique was direct composite restoration with a silicon putty matrix to make the shape of thelingual surfaces of the restorations. Before the restoration procedure, it was performed “in office”bleaching technique, in addition to the case planning with the assistance of a wax-up. The tooth whitening therapy followed by direct composite restorations was effective, contributing to clinical success, esthetic and patient´s satisfaction.

Influence of different dentin drying methods on adhesive behavior of composite restorations

Aim: The aim of this study was to evaluate, in vitro, the influence of four different dentin drying methods (air drying for 10s, absorbent paper, endodontic suction cannula and air drying for 10s with subsequent re-wetting with distilled water), after etching with phosphoric acid gel 37%, on bond strength and microleakage of composite restorations. Material and Methods: Twenty sound bovine incisors were selected and sectioned transversely. The buccal surfaces were frayed until exposure of dentin, etched and washed with distilled water. Each specimen was subjected to one of the four different drying methods. A 3-step total-etch adhesive system (Adper Scotchbond™ Multi-Purpose) was used on 10 teeth and on the other 10, a 2-step total-etch adhesive system (Adper Single BondT™ 2) was used. Composite resin restorations in cylindrical shapes were made and, after thermocycling, the teeth were subjected to the microshear bond strength test. Cervical areas of the teeth were prepared and restored with the same techniques describe above. Cervical restorations were cut and subjected to microleakage analysis in the cervical margin. Data obtained were tabulated and statistically analyzed, using ANOVA, Chi-square and Kruskal-Wallis tests, and the significance level was set at 5%. Results: The results showed no statistically significant differences among the groups tested. Conclusions: It was concluded that all drying methods tested represent feasible alternatives to clinical application for total etch dentin-bonding agents.

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.

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.

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).

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...

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.

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.

Qual é a sua opinião sobre utilizar ou não utilizar em sua rotina clínica a clorexidina como etapa adicional quando empregados sistemas adesivos convencionais de duas ou três etapas clínicas?

(Por Alberth D. Correa-Medina) Essa questão é complexa para responder, pois alguns pontos ainda estão em discussão, tais como: a) as razões que indicam o uso de clorexidina; b) se utilizada, em que momento do procedimento adesivo é melhor, antes ou depois do condicionamento ácido?; e c) pode ser utilizada com sistemas adesivos convencionais e autocondicionantes? A clorexidina, em concentrações menores que 1%, tem ação bacteriostática, provocando danos na membrana e perda de substâncias de baixo peso molecular, tais como potássio e íons de flúor, embora não produza a morte bacteriana. Entretanto, em concentrações superiores a 1% causa coagulação e precipitação do citoplasma, produzindo morte celular, sendo altamente bactericida. Essa substância age sobre gram-positivos e negativos aeróbios e anaeróbios. Tem várias aplicações e, na área da Odontologia Restauradora, tem sido indicada para a limpeza de cavidades antes que sejam restauradas, porque proporciona desinfecção adequada dos tecidos dentários. Em lesões cariosas em que toda estrutura infectada tenha sido removida, indicava-se aplicar essa solução como uma forma de assegurar a remoção completa de restos de organismos que poderiam ficar presentes na cavidade. [...]

Influência do tratamento de superfície na resistência de união por cisalhamento de um cerômero indireto / Surface treatment effect on shear bond strength of an indirect ceromer

Objetivo: o presente estudo realizou uma análise comparativa da resistência ao cisalhamento em dentina após diferentes tratamentos de superfície do cerômero BelleGlass HP (Kerr). Materiais e métodos: para isso, trinta molares humanos tiveram suas faces livres desgastadas até expor a superfície dentinária, nas quais foram cimentados os corpos de prova (belleGlass HP) com cimento resinoso (RelyX ARC, 3M ESPE), com três tratamentos de superfície: grupo 1 (controle): sem tratamento de superfície; grupo 2: condicionamento com ácido fluorídrico 10%; e grupo 3: jateamento com óxido de alumínio com granulação de 50um. Os espécimes foram avaliados em relação à resistência de união por cisalhamento, com velocidade de 1,0mm/min. Os dados foram analisados estatisticamente através dos testes ANOVA e Tukey, com nível de significância de 5%. Resultados: como resultado, obteve-se diferenças estatisticamente significativas (P=0,002) entre o grupo controle e o grupo 3. Conclusão: concluiu-se que o tipo de tratamento de superfície do cerômero Belleglass influenciou a resistência de união dos espécimes cimentados, sendo o jateamento com óxido de alumínio o que apresentou melhor desempenho

Aim: The present study showed a comparative analysis of shear bond strength of a ceromer after different surface treatments. Material and methods: For that, thirty human molars had their free surfaces drilled until exposing the dentin tissue, where the ceromer specimen were cemented (belleGlass HP), with three surface treatments before cementation: control group, without surface treatment (group 1); group 2: etched with fluoridric acid (10%) and group 3: etched with aluminum oxide jet (50um). All groups were tested in a universal testing machine, with 1mm/min crosshead speed, in a shear bond strength test. Data were analysed by ANOVA and Tukey tests. Results: It was shown statistically significant differences (p=0.002) between control group and group 3. Conclusions: Ceromer surface treatment Intervenes on shear bond strength to dentin, being the aluminium oxide jet the best way to improve bond strength.

Influence of different surface conditioning protocols on microtensile bond strength of self-adhesive resin cements to dentin.

STATEMENT OF PROBLEM: According to manufacturers, bonding with self-adhesive resin cements can be achieved without any pretreatment steps such as etching, priming, or bonding. However, the benefit of saving time with these simplified luting systems may be realized at the expense of compromising the bonding capacity. PURPOSE: The purpose of this study was to assess whether different dentin conditioning protocols influence the bond performance of self-adhesive resin cements to dentin. MATERIAL AND METHODS: Flat dentin surfaces from 48 human molars were divided into 4 groups (n=12): 1) control, no conditioning; 2) H(3)PO(4), etching with 37% H(3)PO(4) for 15 seconds; 3) SEBond, bonding with self-etching primer adhesive (Clearfil SE Bond); and 4) EDTA, etching with 0.1M EDTA for 60 seconds. The specimens from each dentin pre-treatment were bonded using the self-adhesive cements RelyX Unicem, Maxcem or Multilink Sprint (n=4). The resin-cement-dentin specimens were stored in water at 37°C for 7 days, and serially sectioned to produce beam specimens of 1.0 mm(2) cross-sectional area. Microtensile bond strength (µTBS) testing was performed at 1.0 mm/min. Data (MPa) were analyzed by 2-way ANOVA and Tukey multiple comparisons test (α=.05). Fractured specimens were examined with a stereomicroscope (x40) and classified as adhesive, mixed, or cohesive. Additional bonded interfaces were evaluated under a scanning electron microscope (SEM). RESULTS: Cement-dentin µTBS was affected by the dentin conditioning approach (P<.001). RelyX Unicem attained statistically similar bond strengths to all pre-treated dentin surfaces. H(3)PO(4)-etching prior to the application of Maxcem resulted in bond strength values that were significantly higher than the other groups. The lowest µTBS were attained when luting Multilink Sprint per manufacturers' recommendations, while H(3)PO(4)-etching produced the highest values followed by Clearfil SE bonding and EDTA. SEM observations disclosed an enhanced potential of the self-adhesive cements to form a hybrid layer when applied following manufacturer's instructions. CONCLUSIONS: When evaluated self-adhesive resin cements are used, selectively etching dentin with H(3)PO(4) prior to luting results in the most effective bonding.

Effect of two axial wall height preparations on the retentive properties of full crowns using three different cements.

This study evaluated how different tooth preparation heights and luting cements affected the retention of metallic full crowns. Tooth preparations were made on 60 extracted maxillary premolars with occluso-cervical heights of 4.0 or 5.0 mm. The nickel chromium (NiCr) metallic crowns in each group were subdivided randomly into three groups (n = 10); the samples in each group were cemented with either a self-adhesive resin cement, a conventional resin cement, or a zinc phosphate cement. Cementation was performed by applying 5.0 kg pressure in 50% relative humidity. Specimens were stored in 100% humidity at 37 degrees C for seven days, at which time they were subjected to a vertical tensile test with a universal testing machine at 0.5 mm/min. Data (Kgf) were analyzed by two-way ANOVA and Tukey's multiple comparisons tests (alpha = 0.01). There was a significant difference in mean force in the height preparations (P < 0.001) and in tensile strength (P < 0.001) among the resin cements. Regardless of the cement used, 5.0 mm high preparations showed significantly higher mean forces than the 4.0 mm high preparations. The self-adhesive resin cement showed significantly higher mean tensile strength than the conventional resin cement; the zinc phosphate cement displayed the lowest retention values. The self-adhesive resin cement displayed retention rates twice that of the zinc phosphate cement.

Effect of whitening dentifrices on the superficial roughness of esthetic restorative materials.

PURPOSE: The purpose of this study was to investigate the surface roughness (Ra) of different esthetic restorative materials following simulated toothbrushing using different whitening dentifrices. MATERIALS AND METHODS: Cylinders of Esthet-X (Dentsply Caulk, Milford, DE, USA), Durafil VS (Heraeus Kulzer, Wehrheim, Germany), and Vitremer (3M ESPE, St. Paul, MN, USA) were made using molds (4 mm in diameter for 2 mm in height). The superficial roughness was evaluated using a profilometer (Ra) with a cutoff length of 0.25 mm and a speed of 0.1 mm/s. The specimens (N=13) were submitted to 7,500 brushing cycles using five different toothpastes: (1) Crest Regular (control; Procter & Gamble): silica abrasive (C); (2) Crest Extra Whitening (Procter & Gamble, Cincinnati, OH, USA): bicarbonate+calcium pyrophosphate (CE); (3) Dental Care A & H (Arm & Hammer, Camilla, GA, USA): bicarbonate (DC); (4) Rembrandt Plus Whitening (Oral B Laboratories, Belmont, CA, USA): carbamide peroxide+alumina/silica (RP); and (5) experimental: hydrogen peroxide+calcium carbonate (EX). RESULTS: The data were analyzed by analysis of variance and Tukey's test (alpha=.05) for each restorative material, and the results [difference between final and initial roughness: Ra(F)-Ra(I) in microm] were as follows: Esthet-X: EX=0.15+0.07a; RP=0.29+0.16a; CE=0.96+0.33b; C=1.03+0.29b; DC=1.48+0.37b; Durafil VS: RP=0.09+0.07a; EX=0.55+0.23abc; C=0.96+0.26bc; CE=1.03+0.33cd; DC=1.09+0.37d; and Vitremer: EX=0.10+0.08a; RP=0.26+0.19a; CE=0.94+0.27b; DC=1.13+0.46bc; C=1.50+0.32c (different letters mean differences among groups). CONCLUSION: It was verified that the dentifrices containing carbamide or hydrogen peroxide along with alumina+silica and calcium carbonate, respectively (groups 4 and 5), produced minor changes in Ra when compared with the control group and with those dentifrices containing bicarbonate (groups 2 and 3). CLINICAL significance The results of this study indicate that whitening dentifrices evaluated containing silica or calcium carbonate were less abrasive when used on the resin-based esthetic restorative materials than those that contain sodium bicarbonate.

Influence of different tests used to measure the bond strength to dentin of two adhesive systems.

PURPOSE: To investigate the behavior of two bonding systems: self-etching primer Clearfil Liner Bond 2V (CLB) and total-etch Single Bond (SB) when submitted to two bond strength tests: shear bond strength (SBS) and microtensile (MTBS). METHODS: Flat dentin surfaces were obtained at the facial surface of extracted bovine incisors. muTBS started with adhesive application and incremental resin composite insertion. Samples were then sliced into 1 mm slabs parallel to the long axis of the tooth. Half of the specimens from each group were trimmed in order to obtain dumbbell-shaped (D) specimens with a cross-sectional area of 1 mm2, and in the other half of the group, the slabs were cut into beams (B) with a cross section of 1 mm2 area. Specimens were individually fractured on a microtensile apparatus. For SBS, crown segments were embedded in polyester resin and a flat dentin surface was exposed for bonding. After adhesive and restorative procedures were accomplished, the specimens were kept in water for 24 hours prior to bond testing. The tests were performed in a universal testing machine. MPa values were analyzed by Tukey's test (P < 0.05), two-way ANOVA (muTBS) and Student's t-test (SBS). RESULTS: Mean values (SD) on muTBS were: SB/B: 42.6 (15.1), SB/D: 35.4 (6.8), CLB/B: 14.3 (10.3) and CLB/D: 27.0 (7.9). SBS values (SD) were: SB: 17.3 (5.6) and CLB 15.9 (7.2). Beam specimens bonded with CLB presented the lowest results. SBS did not show statistical differences between groups. The results showed that the shear bond test seemed to lack the sensitivity that is required to detect subtle differences between bonding agents or procedures.