Placement Technique and Microleakage in Posterior Composite Restorations

Abstract

Context : Advances in composite restorative materials have positioned them as credible alternatives to dental amalgam. However, polymerization shrinkage and the resultant microleakage remain major obstacles in the successful use of these materials. Aims: The aim of this study was to investigate the effects of placement technique on microleakage of Quixfil ® composite restorations bonded with Xeno III ® bonding agent Settings and Design : In vitro study. Materials and Methods : Thirty-four cylindrical cavities measuring 5 mm in diameter and 3 mm in depth were prepared on the buccal aspect of extracted human teeth. The apices of all the teeth were sealed and the teeth randomly assigned into the bulk and the incremental groups for restoration. Restorations were polished and two layers of nail varnish applied on all tooth surfaces except a rim of 1 mm around the restorations. The teeth were thermo-cycled and stained with 2% methylene blue dye. The restorations were sectioned and examined under light microscopy. Dye penetration on the tooth-restoration interface was scored on an ordinal scale of 0 to 4. Statistical Analysis Used : Pair-wise comparison of the two placement groups was done using the Wilcoxon Signed Ranks Test. Results : No statistically significant difference was observed in the microleakage of the two study groups ( P value > 0.05). Conclusions : There is no statistically significant difference in the microleakage of the bulk and the incremental Quixfil restorations. It is feasible to place Quixfil restorations in layers of up to 3 mm in depth.