title: 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.
  
  
  BACKGROUND
  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.
  
  
  CONCLUSIONS
  These results suggest that Er:YAG laser is useful for class I cavity preparation from the viewpoint of microleakage.
authors: Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan.
authors: M F
authors: MF
authors: Khan
authors: K
authors: K
authors: Yonaga
authors: Y
authors: Y
authors: Kimura
authors: A
authors: A
authors: Funato
authors: K
authors: K
authors: Matsumoto
mesh_terms: D003188:Composite Resins; D003723:Dental Amalgam; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003754:Dental High-Speed Equipment; D003763:Dental Leakage; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods; D004871:Erbium; D005899:Glass Ionomer Cements; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D016037:Single-Blind Method; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D005899:Glass Ionomer Cements; D004871:Erbium; D003723:Dental Amalgam