Chitosan improves the durability of resin-dentin interface with etch-and-rinse or self-etch adhesive systems.

Vitória Leite PASCHOINI,Isabella Rodrigues ZIOTTI,Aline Evangelista SOUZA-GABRIEL,Cláudio Roberto NERI,Silmara Aparecida Milori CORONA

doi:10.1590/1678-7757-2021-0356

Vitória Leite PASCHOINI, Isabella Rodrigues ZIOTTI + Show 3 more

Open Access

https://doi.org/10.1590/1678-7757-2021-0356

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Abstract

Degradation of the dentin-resin interface can occur due to hydrolysis of exposed collagen, resulting in reduced bond strength. This study assessed the effect of dentin treatment with chitosan combined with an etch-and-rinse or self-etch adhesive system on improvement of bond strength and preservation of the interface durability. Methodology Enamel was removed from 80 molars and the teeth were divided into two groups: without chitosan (control) or with 2.5% chitosan gel (1 min). They were further subdivided into two subgroups according to the adhesive system: etch-and-rinse or self-etch. Dentin was restored using a composite resin. Half of the specimens from each restored group were subjected to interface aging and the remaining specimens were used for immediate analysis. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test (n=10), chemical composition testing using Fourier-transform infrared (FTIR) spectroscopy (n=4) and energy-dispersive spectroscopy (EDS) (n=5), and morphological analysis of the adhesive interface using scanning electron microscopy (SEM) (n=5). Data were analyzed using three-way ANOVA.Results Chitosan improved the µTBS of the adhesive interface when compared with the control group (p=0.004). No significant differences were observed in dentin adhesion between the adhesive systems (p=0.652). Immediate µTBS was not significantly different from that after 6 months (p=0.274). EDS and SEM did not show significant differences in the chemical and structural composition of the specimens. FTIR showed a decrease in the intensity of phosphate and carbonate bands after using chitosan.Conclusions Dentin treatment with chitosan combined with an etch-and-rinse or self-etch adhesive system improved the immediate and preserved the 6-month bond strength of the adhesive interface.

Highlights

In dental procedures, adhesives are combined with composite resin to create a strong bond to resolve many restorative issues.1 Different adhesive protocols that can achieve a hybrid layer include the etch-andrinse and the self-etch strategies.2–4An etch-and-rinse adhesive system applies phosphoric acid at a concentration between 30% and 40%3–5 to remove smear layer
This study assessed the effect of dentin treatment with chitosan combined with an etch-and-rinse or self-etch adhesive system on improvement of bond strength and preservation of the interface durability
The null hypotheses of the study were: 1) Chitosan gel combined with an etch-and-rinse or self-etch adhesive system would exhibit no significant difference in microtensile bond strength of resin to dentin; 2) There is no difference in the amount of the chemical elements of dentin with or without the chitosan gel, using energy-dispersive spectroscopy (EDS); 3) Morphology of the adhesive interface would not exhibit difference among groups; 4) There is no difference in the bands intensity of the chemical substances of dentin after using chitosan combined with etch-andrinse or self-etch adhesive system, using Fourier-transform infrared (FTIR)

Summary

Introduction

Adhesives are combined with composite resin to create a strong bond to resolve many restorative issues. Different adhesive protocols that can achieve a hybrid layer include the etch-andrinse and the self-etch strategies.2–4An etch-and-rinse adhesive system applies phosphoric acid at a concentration between 30% and 40%3–5 to remove smear layer. Adhesives are combined with composite resin to create a strong bond to resolve many restorative issues.. Different adhesive protocols that can achieve a hybrid layer include the etch-andrinse and the self-etch strategies.. An etch-and-rinse adhesive system applies phosphoric acid at a concentration between 30% and 40%3–5 to remove smear layer. Dentin is demineralized up to a depth of 3–5 μm, exposing the collagen fibrils and allowing adhesive and resin infiltration.. Mechanical interlocking of resin tags within the acidetched surface provides a favorable bond to the dental substrate.. Since dentin adhesion is more challenging than enamel adhesion, self-etch adhesives were introduced to control the sensitivity of the etch-and-rinse technique to humidity and to simplify the procedure.. Acid etching of dentin can damage the collagen matrix and decrease the durability of the restorative treatment. Dentin is demineralized up to a depth of 3–5 μm, exposing the collagen fibrils and allowing adhesive and resin infiltration. mechanical interlocking of resin tags within the acidetched surface provides a favorable bond to the dental substrate. since dentin adhesion is more challenging than enamel adhesion, self-etch adhesives were introduced to control the sensitivity of the etch-and-rinse technique to humidity and to simplify the procedure. acid etching of dentin can damage the collagen matrix and decrease the durability of the restorative treatment.

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