Study of Microleakage at Class I Cavities Prepared by Er:YAG Laser Using Three Types of Restorative Materials

Abstract

OBJECTIVE: The purpose of this in vitro study were to investigate microleakage at class I cavities filled with amalgam, composite resin, or glass-ionomer after preparation by Er:YAG laser and to compare the results with those by a conventional method using an air turbine. SUMMARY BACKGROUND DATA: There has been no report of a study of microleakage on class I cavities prepared by Er:YAG laser. METHODS: Ninety-six extracted human premolar and molar teeth were used in this study. Forty-eight class I cavities were prepared by Er:YAG laser and 48 class I cavities by air turbine. After preparation, each of the 2 groups was further subdivided into 3 groups, respectively, and cavities in each of these subgroups were filled by 1 of 3 types of restorative materials. Microleakage at the restored cavities was assessed by the dye penetration method and scanning electron microscopy (SEM). RESULTS: Minimal or moderate leakage was evident at most of the composite resin or glass-ionomer restorations, whereas moderate or severe leakage was observed at most of the amalgam restorations as shown by the dye penetration method. There was significant difference among the 3 restorative materials (p < 0.05), but there was no significant difference in microleakage between the cavities prepared by Er:YAG laser and those by air turbine (p > 0.05). SEM evaluation demonstrated good adaptation with most of the composite resin or glass-ionomer restorations, but amalgam restorations showed slightly poorer adaptation. CONCLUSION: These results suggest that Er:YAG laser is useful for class I cavity preparation from the viewpoint of microleakage.