Efeito do digluconato de clorexidina na estabilidade da união de sistemas adesivos e dentina sadia ou afetada por carie / Effect of clorhexidine digluconate on the bond strength of etch-and-rinse adhesives to normal/caries-affected dentin

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate on the bond strength of etch-and-rinse adhesives applied to sound (SD) and caries-affected dentin (CAD). It is hypothesized that CHX does not have a detrimental effect on the bond strength to sound and caries-affected dentin, as well as that CHX may decelerate the mechanical degradation of resin-dentin bonds over time. Twenty, carious, extracted molars were included in this study. The occlusal enamel of all teeth was removed with a slowspeed diamond saw, under copious water-cooling, in order to expose a flat surface, where the CAD was surrounded by SD. The CAD and SD surfaces were etched with 35% phosphoric acid gel for 15 s, rinsed for 30 s with tap water and dried with oil/water-free air. In the control groups, the dentin substrates were re-hydrated with distilled water, while in the experimental groups were re-hydrated with 2 wt% chlorhexidine digluconate (CHX). After a dwell time of 60 s, excess solution was removed with absorbent paper. The dentin surfaces were then bonded with one of the etch-and-rinse adhesives, Schotchbond Multi- Purpose (MP) or Single Bond 2 (SB). Composite build-up was performed with Z250 and stored in phosphate-buffered saline (PBS, pH 7.4) at 37ºC for 7 days. After this period, the restored teeth were longitudinally sectioned across the bonded interface to produce a series of 0.8 mm2 beams. Part of those specimens was immediately subjected to a microtensile test. The remaining specimens were stored in PBS at 37°C for six months and then tested in tension under the same protocol. Data were analyzed by ANOVA and Holm-Sidak test for multiple comparisons (? = 0.05). The first anticipated hypothesis was confirmed, the use of CHX after acid-etching did not have detrimental effect on the immediate bond strength to both normal and caries-affected dentin and the second anticipated hypothesis was partially confirmed, the mechanical degradation of resin-dentin bonds may be delayed by the application of chlorhexidine (CHX) to sound dentin after phosphoric acid-etching. Attempts to use chlorhexidine adjunctively with conventional acid-and-rinse adhesives may play a clinically-relevant role on the preservation of resin-dentin bonds.

ASSUNTO(S)

dental caries caries dentarias resistance of materials adesivos dentarios resistencia de materiais dental adhesives clorexidina chlorhexidine

ACESSO AO ARTIGO

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