Effects of pulsed Nd:YAG laser on microleakage of composite restorations in class V cavities

The purpose of this study was to evaluate the effects of the pulsed Nd:YAG laser on the decrease of dentinal microleakage beneath the restoration. Materials and method: 32 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 a 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 I week in 2% basic fuchsin solution. Specimens were then sliced longitudinally and evaluated under a digital scanner for the extent of dye penetration. Result: 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. (C) 2003 Published by Elsevier Science B.V.