ABSTRACT
Abstract The objective of this study was to investigate microtensile bond strength (MTBS) and interfacial adaptation (IA) of bulk-fill restorative systems bonded to dentin in Class-I-preparations. Box-shaped preparations (4-mm-long, 3-mm-wide, 2-mm-high) made in extracted molars, and Teflon matrix with the same dimensions positioned over the occlusal surface were restored, providing a total of 4-mm composite depth using three bulk-fill restorative systems: Tetric EvoCeram Bulk Fill with Tetric N-Bond (TEC/TNB), SureFil SDR Flow with XP Bond (SDR/XPB) and Filtek Bulk Fill Flowable Restorative with Scotchbond Universal (FBF/SBU); or incrementally restored with a conventional restorative system: Herculite Classic with OptiBond FL (HER/OBF). The specimens were sectioned into beams and the MTBS measured after 24-hours or one-year storage. For evaluation of IA, round-tapered tooth preparations (3-mm-diameter, 1.5-mm-deep) were made, restored with each material and their cross-sectional images were obtained after 24-hours using optical coherence tomography (OCT). The gap percentage for each restoration system was calculated using image analysis software. MTBS for both storage periods: HER/OBF=TEC/TNB=SDR/XPB>FBF/SBU (ANOVA, Tukey's post-hoc, P<0.05) differed significantly among groups, which values were significantly reduced after one-year. SDR/XPB showed comparatively lesser gap formation at the tooth-interface after 24 hours (ANOVA, Dunnett's T3 post-hoc, P<0.05). For deeper restorations, bond strength of TEC/TNB and SDR/XPB can be equal to that of HER/OBF after 24-hours and one-year; however, in a shallower preparation, SDR/XPB showed greater initial interfacial adaptation.
Subject(s)
Humans , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Dental Marginal Adaptation , Composite Resins/chemistry , Resin Cements/chemistry , Dentin/drug effects , Surface Properties , Tensile Strength , Time Factors , Materials Testing , Reproducibility of Results , Analysis of Variance , Microscopy, Confocal , Dental Restoration Failure , Tomography, Optical CoherenceABSTRACT
This paper presents the state of the art of self-etch adhesive systems. Four topics are shown in this review and included: the historic of this category of bonding agents, bonding mechanism, characteristics/properties and the formation of acid-base resistant zone at enamel/dentin-adhesive interfaces. Also, advantages regarding etch-and-rinse systems and classifications of self-etch adhesive systems according to the number of steps and acidity are addressed. Finally, issues like the potential durability and clinical importance are discussed. Self-etch adhesive systems are promising materials because they are easy to use, bond chemically to tooth structure and maintain the dentin hydroxyapatite, which is important for the durability of the bonding.
Este artigo apresenta o estado da arte de sistemas adesivos autocondicionantes. Quatro temas são apresentados nesta revisão: o histórico desta categoria de agentes de união, o mecanismo de adesão, as características/propriedades, e a formação da zona ácido-base resistente nas interfaces esmalte/dentina-adesivo. Além disso, as vantagens relativas aos sistemas de condicionamento total ( etch-and-rinse ) e as classificações dos sistemas adesivos autocondicionantes de acordo com o número de passos e acidez são abordados. Por fim, são discutidas questões como a durabilidade potencial e a importância clínica. Sistemas adesivos autocondicionantes são materiais promissores porque são fáceis de usar, unem-se quimicamente à estrutura do dente e preservam a hidroxiapatita dentinária, o que é importante para a durabilidade da ligação.