The effect of two different flowable composites on the durability of a repaired water stored resin composite. A nano-leakage study

Abstract

This study was conducted to evaluate the effect of using two types of flowable resin composite and storage time on nano-leakage of repaired water aged resin composite. A total of 30 resin composite discs were stored in distilled water for 6-months and then divided into 6 experimental groups (n=5/group) according to the two variables of the study: Variable 1: Flowable composite, 3 groups (no-flowable, high-viscosity and low-viscosity flowable composites), and Variable 2; Storage time after repair, 2 groups (24-hours and 6-months). After 6-months, discs were repaired according to the flowable resin composite application and stored for either 24-hours or 6-months. After the recommended storage time, each disc was sectioned into 2 halves and each half was prepared for silver nitrate staining procedures to evaluate nano-leakage under SEM. Three photomicrographs were taken for each half-slab, resulting in 30 photomicrographs/group, which were analysed using ImageJ software. Data were evaluated using Kruskal-Wallis/Mann-Whitney test (P=0.05). The use of flowable composite had no significant effect on nano-leakage score (P=0.129), while storage time showed a statistically significant effect of nano-leakage score (P˂0.0001). There was no statistically significant difference regarding the use of flowable resin composite either at 24-hours and 6-months storage times (P˃0.05). There was a statistically significant difference between 24-hours and 6-months storage periods for all experimental variables (P˂0.05).