Effect of cyclic loading on microleakage of silorane based composite compared with low shrinkage methacrylate-based composites

Abstract

Background: There are many concerns regarding the marginal seal of composite restorations,
especially when composite restorations are subjected to cyclic loading. The aim of this study was
to evaluate the effect of cyclic loading on the microleakage of silorane based composite compared
with low shrinkage methacrylate-based composites in class V cavities.
Materials and Methods: In this in vitro study, class V cavities were prepared on the facial and lingual
surfaces of 48 human premolars (96 cavities). The teeth were randomly divided into four groups
of 12 teeth (24 cavities) each and restored as follows: Group 1 (Siloran System Adhesive + Filtek
P90), Group 2 (All Bond SE + Aelite LS Posterior), Group 3 (Futurabond NR + Grandio), and
Group 4 (G-Bond + Kalore-GC). All the specimens were thermocycled for 2000 cycles (5–55°C)
and then half of the specimens from each group, were Load cycled. All teeth were immersed in 0.5%
basic fuchsine dye, sectioned, and observed under a stereomicroscope. Data were analyzed using
Wilcoxon test, Kruskal–Wallis, and Mann–Whitney U-tests. P < 0.05 was considered as signifi cant.
Results: In both unloaded and loaded groups, no statistically signifi cant differences were observed
among four composites at the occlusal margin, but a signifi cant difference in gingival microleakage
was found between Aelite and silorane. Occlusal and gingival microleakage was not affected by
cyclic loading in none of the four restorative materials.
Conclusion: Silorane did not provide better marginal seal than the low shrinkage methacrylate-based
composites (except Aelite). In addition, cyclic loading did not affect the microleakage of evaluated
composite restorations.
Key Words: Composite resins, dental leakage, polymerization, silorane resins