Microleakage around Class V Composite Restorations after Ultrasonic Scaling and Sonic Toothbrushing around their Margin.

Objectives: to measure microleakage around class V composite restorations after piezoelectric ultrasonic scaling and sonic toothbrushing. Methods: 3 mm X 2 mm X 1.5 mm boxes were prepared on buccal and lingual surfaces of extracted molars centered on the cementum-enamel junction. Halfthe preparations were beveled (0.5 mm). Preparations were restored with composite and polished. Restorations on one side of the teeth were either traced with an ultrasonic scaler (60 seconds, n = 16) or brushed in a sonic toothbrushing machine (2 hours, n = 16). After thermocycling (10,000 cycles/5-55 degrees C), specimens were immersed in 5 wt% Fuchsine solution (24 hours). Samples were sectioned and evaluated for percentage of dye penetration. Data were analyzed with an exact Wilcoxon rank-sum test and exact Wilcoxon signed-rank test (alpha = 0.05). Results: Microleakage was observed at the cementum-composite interface but not the enamel-composite interface. I here was not a statistically significant effect ofthe bevel for ultrasonic scaling or for sonic toothbrushing. Data obtained with and without a bevel were combined and a statistically significant difference in microleakage between the treatment and control sides ofthe tooth were found for ultrasonic scaling (32.5%+/- 44.9% n = 16; p = 0.016) but not sonic toothbrushing (2.5% +/- 41.2%, n = 16; p = 1.0). Conclusions: Piezoelectric ultrasonic scaling increased microleakage at cementum-composite interface and there was no difference in microleakage with the use of a bevel.