Effect of Lactic Acid on Microleakage of Class V Low-Shrinkage Composite Restorations

To assess the effect of lactic acid (LA) on microleakage of silorane-based composite restorations and methacrylate-based composites with self-etch and etch-and-rinse bonding systems.
Class V cavities were prepared in 120 extracted human teeth, divided into four groups and restored as follows: 1. Silorane-based composite㿝 adhesive system (P90); 2. Filtek Z250 Bond (Z250SE); 3. Filtek Z350 Bond (Z350SE) and 4. Filtek Z250䨩 Bond (Z250SB). Half of the samples in each group were immersed in LA and the other half in distilled water (DW) for seven days. Degree of microleakage was determined by dye penetration. Data were analyzed using Kruskal Wallis and Mann Whitney-U tests (type 1 error was considered 0.05 for primary and 0.017 for post-hoc tests).
No significant difference was found in microleakage between LA and DW groups. The difference among groups in gingival margin microleakage was significant (P Immersion in LA has no effect on microleakage of class V composite restorations regardless of the type of composite and adhesive system. At gingival margins, the highest microleakage occurred in Z250SB followed by P90 and self-etch groups.