Effect of an erosive challenge on the enamel-composite resin interface in primary teeth: an in vitro study

ABSTRACT

AIM: The aim of this study was to evaluate whether different adhesive systems (etch-and-rinse or self-etch) render enamel-composite resin interface in primary teeth more susceptible to erosive challenge. MATERIAL AND METHODS: Thirty enamel specimens from caries-free primary incisors were selected and cavities were prepared for restoration. According to adhesive protocols, specimens were divided into groups G1 (Adper Single Bond 2), G2 (Adper SE Plus), and G3 (35% phosphoric acid + Adper SE Plus). After restorative procedures, half of the surface of enamel and restorative material was protected with nail varnish, thus, only half of the sample was subjected to the erosive challenge (immersion in Coca-Cola®, 3 cycles of 5 minutes, for 5 days). Samples were analysed quantitatively through Knoop microhardness, the indentations were made on enamel-composite interface. Data were submitted to statistical analysis (Student's t test, two-way ANOVA, p<0.05). RESULTS: It showed that different adhesive systems did not significantly affect the percentage of superficial microhardness change after an erosive challenge (p=0.387). However, although no significant difference was observed, G2 (self-etch system) showed the lowest percentage of superficial microhardness change. CONCLUSION: The use of different adhesive systems did not influence superficial microhardness of enamel-composite interface after an erosive challenge. The incomplete removal of the smear layer, though self-etch systems, suggests a greater ability to withstand the erosive challenge on the enamel-resin interface.