Nanoleakage phenomenon on deproteinized human dentin

Abstract

Objective:The purpose of this study was to evaluate the influence of dentin deproteinization on the nanoleakage phenomenon.Material and Methods:Class V cavities were prepared in 12 human molars with cervical margins located in dentin. The cavities were assigned to 2 groups (n=6) according to dentin treatment: Group I - dentin treated in accordance with the manufacturer’s instructions and Group II - dentin treated following the manufacturer’s instructions + 10% NaOCl. Each group was sub-divided into three groups, according to the DBS (dentin bonding system) used: Scotchbond Multi Purpose (SBMP), Prime & Bond NT (PB) and Clearfil SE Bond (SE), which were applied according to manufacturer’s instructions. The cavities were restored with composite resin, and the specimens were immersed in a tracer agent (AgNO3 50%) for 24 h. The teeth were sectioned buccolingually through the center of the restorations, and nanoleakage pattern was evaluated by scanning electron microscopy (SEM) using the backscattered electron image mode.Results:SEM analysis showed different nanoleakage patterns for each DBS. Irrespective of dentin treatments, all SBMP specimens showed nanoleakage. SE did not show any nanoleakage with both dentin treatments used. PB showed nanoleakage within the hybrid layer only in Group I.Conclusions:The influence of dentin deproteinization on the nanoleakage phenomenon was dependent on dentin bonding system formulation and bonding strategies.

Shear bond strength of universal adhesive systems to a bioactive dentin substitute (Biodentine®) at different time intervals

“…Lower shear bond strength was detected in groups with PB, another acetonecontaining adhesive system, compared to the other groups. We note that high molecular weight monomers like urethane dimethacrylate and dipenta erythritol penta acrylate monophosphate in composition of PB have led to a decrease in bond strength values through reducing the diffusion capacity of the adhesive [29] .…”

Fracture Strength and Nanoleakage of Weakened Roots Reconstructed Using Relined Glass Fiber–Reinforced Dowels Combined with a Novel Prefabricated Core System

“…Residual water within the adhesive may lead to areas of incomplete polymerization of the adhesive or sequestrations of more hydrophilic oligomers in these specific areas. 50,51 This in vitro study presented limitations common to tests conducted on human teeth, such as specific dimensions, static compressive load, and fixed angulations. Clinical extrapolation of the results must be done judiciously and prudently, since it is not possible to simulate all the conditions of the oral environment.…”

“…Meanwhile, the occurrence of the reticular mode of nanoleakage represents areas in which water was incompletely removed from the resin/dentin interfaces. Residual water within the adhesive may lead to areas of incomplete polymerization of the adhesive or sequestrations of more hydrophilic oligomers in these specific areas …”

Influência da Remoção de Colágeno Sobre a Resistência de União de Adesivos Autocondicionantes

“…A subseqüente hidrólise dessa trama conduziria à degradação do processo adesivo, resultando em um decréscimo da força, assim como em um aumento da microinfiltração ao longo do tempo 23 . A contribuição da camada híbrida para a resistência adesiva vem sendo investigada 24 e o processo para formação dessa camada tem apresentado muitas variáveis 25 , as quais aliadas à incapacidade de constatação clínica de sua formação fazem com que seja considerada uma técnica sensível. Deste modo, diante dos questionamentos quanto à sua efetividade, diversos autores têm pesquisado novas alternativas de adesão dentinária [26][27][28] .…”