EFEITO DA TÉCNICA DE APLICAÇÃO DO EDTA COMO PRÉ- CONDICIONAMENTO DA DENTINA ESCLERÓTICA E ESMALTE NA RESISTÊNCIA DE UNIÃO DE ADESIVOS UNIVERSAIS

Abstract

The aim of this study was to investigate the effect of different protocols of 17% EDTA (ethylene diamine tetra acetic acid) pre-conditioning on the etching pattern and immediate bond strength of universal adhesives to enamel and sclerotic dentin. Forty bovine teeth with sclerotic dentin and twenty human third molars were randomly divided into eight groups resulting from the combination of the main factors surface treatment (none, 2-min EDTA conditioning manual application; 30-second EDTA manual application; 30-second EDTA sonic application) and adhesive system (Scotchbond Universal Adhesive [SBU] and Prime & Bond Elect [PBE]). Resin-dentin and enamel-dentin bonded specimens were prepared and tested under the microtensile bond strength (μTBS) and microshear bond strength (μSBS) tests respectively. The etching patterns produced on the enamel and on the sclerotic dentin surfaces were evaluated under scanning electron microscope (SEM). Results:None of the EDTA pre-conditioning protocols had any impact on the μSBS on enamel (p > 0.05). In sclerotic dentin, the lowest μTBS was observed in the group without EDTA pre-conditioning and the highest in the 30-second EDTA sonic application group. SBU showed the highest μTBS for all the groups (p < 0.05). EDTA preconditioning improved the etching pattern of enamel and dentin in all groups. EDTA pre-conditioning improved the bonding performance and etching pattern of the universal adhesives used in the self-etch mode on sclerotic dentin, mainly when applied for 30 s with the aid of a sonic device. EDTA pre-treatment also improved the retentive etching pattern on enamel but it did not result in higher enamel bond strength.