Effects of Pulsed Nd:YAG Laser on Microleakage of Composite Restorations in Cl V cavities

Objectives:The purpose of this study was to evaluate the effects of pulsed Nd:YAG laser on creation of an impenetrable layer beneath the restoration by melting and recrystalization of dentin. Material & Method: 32 sound extracted premolar teeth were subjected to two standardized, V shaped, class V cavity preparations on both surfaces of buccal & lingual. Cavities were located at 1- 2mm below the CEJ line. Teeth were divided into two groups of experimental and control in a random manner. 20 and 15mJ 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. Result: results indicated that the level of microleakage of laser treated cavities was significantly less than that of untreated cavities (P<0.05) for 20mJ/pulse laser energy. No significant decrease in microleakage level was observed for the 15mJPulse laser energy. Conclusion: The Pulsed Nd:YAG laser with the energy of 20 mJ/Pulse and aforementioned features is appeared to be able to seal dentinal tubules and consequently reduces microleakage toward pulp.