A comparative leakage study on Er, Cr: YSGG laser- and bur- prepared Class V cavities restored with a low-shrinkage composite using different filling techniques

ABSTRACT

Aim: To evaluate the leakage on Er,CrYSGG laser- and bur- prepared Class V cavities restoredwith a silorane-based composite resin using different insertion techniques Methods: 40 cavitieswere outlined according to the type of instrument [Er,CrYSGG laser (3.0 W power, energy perpulse of 150 mJ, fluence of 53.57J/cm2, pulse duration of 140-200 μs, 20 Hz repetition rate and55/65% air/water spray) or diamond bur]; and the type of filling technique (bulk increment orincremental). Four experimental groups were obtained (n=10) G1- diamond bur (DB) andincremental (I); G2- DB and bulk increment (BI); G3- Er,CrYSGG and I; and G4- Er,CrYSGGand BI. Specimens were restored with a silorane-based composite resin (Filtek P90, 3M/ESPE),subjected to 500 thermal cycles, sealed, infiltrated with 2% (w/v) methylene blue and sectioned inhalves. Specimen analysis was scored based on a scale. Statistical analyses were done usingthe Kruskal-Wallis and Student Newman-Keuls tests (α=0.05). Results: Statistically significantdifferences were observed between G2 and G4 (p=0.003) and between G1 and G2 (p=0.028).The filling technique did not influence the pattern of dye leakage in the cavity walls (p=0.151).Conclusions: Less leakage was observed when Er,CrYSGG cavities were restored withsilorane-based composite resin, using the bulk increment technique. Nevertheless, cavities doneusing diamond bur have less leakage only when incrementally restored.