Effect of Selective Dentine Pre-Treatment with Butane Tetracarboxylic Acid on Composite-Dentine Bond.

Abstract

Background: Composites are prone to time-dependent bond degradation. Many measures have been taken to stabilize the bond.

Aim: This in vitro study aims to evaluate the effect of pretreatment with 1,2,3,4-Butane Tetracarboxylic acid (BTCA) on the micro-tensile bond strength (µTBS) of composite resin to dentine and to compare it with the pretreatment using 2% chlorhexidine (CHX).

Materials and methods: Permanent molars (40) extracted for periodontal reasons were selected. Dentine surfaces were exposed using a diamond bur, preconditioned with BTCA for the test group (SIGMA-ALDRICH) and with CHX for the control group, followed by the application of self-etch adhesive (GC G-Premio bond) and composite restoration (GC Solare X). Each group was subdivided to be tested as: Group 1A: after 24 hours with BTCA; Group 1B: after 1 month with BTCA; Group 2A: after 24 hours with CHX; Group 2B: after 1 month with CHX. The µTBS was tested using a universal testing machine. The mode of failure was determined using a stereomicroscope and a scanning electron microscope (SEM).

Result: BTCA pretreatment was able to preserve the bond slightly better than the control group, though not statistically significant either at 24 hours (P = 0.492) or 1 month (P = 0.181). There was no significant reduction in the µTBS between immediate testing and 1-month storage for both groups (P = 0.213 for acid; P = 0.914 for CHX). The mode of failure was predominantly cohesive for both groups, with fewer adhesive failures.

Conclusions: BTCA pre-conditioning is capable of preserving the dentin-composite bond as efficiently as CHX.