Effects of Pulsed Nd:YAG Laser on Microleakage of Composite Restorations in Class V Cavities

OBJECTIVE: The purpose of this study was to evaluate the effects of pulsed Nd:YAG laser on decrease of dentinal microleakage beneath the restoration. METHODS: Thirty-two sound extracted premolar teeth were subjected to two standardized, V-shaped, class V cavity preparations on both buccal and lingual surfaces. Cavities were located at 1-2 mm below the cemento-enamel junction (CEJ) line. The teeth were divided into two groups of experimental and control in an random manner. Both 20 and 15 mJ/pulse laser energies were tested. Etching, bonding, and filling were performed using Tetric ceram composite material. All samples were thermocycled for 1000 cycles, followed by an immersing period of 1 week in 2% basic fuchsin solution. Specimens were then sliced longitudinally and evaluated under a digital scanner for the extent of dye penetration. RESULTS: Our results indicated that the level of microleakage of laser-treated cavities was significantly less than that of untreated cavities (p < 0.05) for 20 mJ/pulse laser energy. No significant decrease in microleakage level was observed for the 15 mJ/pulse laser energy. CONCLUSION: The short pulsed Nd:YAG laser with the energy of 20 mJ/pulse and aforementioned features appeared to be able to reduce microleakage toward pulp.