title: Effects of Er:YAG laser on the sealing of glass ionomer cement restorations of bacterial artificial root caries.
abstract: OBJECTIVE
  The aim of this study was to test the effect of Er:YAG laser irradiation on the marginal sealing of root cavities restored with two glass ionomer cements.
  
  
  BACKGROUND
  For preventing secondary root caries, new technologies for dental caries removal, such as the Er:YAG laser irradiation, have been proposed.
  
  
  METHODS
  Forty-five human teeth were used. Artificial root caries were induced using a microbiological model (Streptococcus mutans). The lesions were removed by three different methods: conventional technique using burs (controls; groups 1 and 2); Er:YAG laser irradiation using dentine preparation parameters (250 mJ, 4 Hz, 80.6 J/cm2; groups 3 and 4); irradiation with the dentine preparation parameters followed by surface conditioning parameters (60 mJ, 2 Hz, 19.2 J/cm2; groups 6 and 7). After each preparation method, three teeth were prepared for scanning electron microscopy morphological observation. The remaining teeth were restored by conventional glass ionomer cement (G1, G3, and G5) or resin modified glass ionomer cement (G2, G4, and G6). After restoration, the samples were thermocycled (1,000 cycles) and prepared for microleakage test.
  
  
  RESULTS
  Scores of less infiltrated samples were observed in groups treated by Er:YAG laser, and the smallest infiltration occurred in the group treated by the dentine preparation parameter, followed by cavity restoration with resin-modified glass ionomer (p < 0.05).
  
  
  CONCLUSIONS
  Our results suggest that root caries removal by Er:YAG laser irradiation, followed by restoration with resin-modified glass ionomer cement, is a suitable choice for dental root caries restoration.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Andréa M D
authors.initials: AM
authors.lastname: Mello
authors.forename: Márcia P A
authors.initials: MP
authors.lastname: Mayer
authors.forename: Fabiano A S
authors.initials: FA
authors.lastname: Mello
authors.forename: Adriana B
authors.initials: AB
authors.lastname: Matos
authors.forename: Márcia M
authors.initials: MM
authors.lastname: Marques
mesh_terms: D003731:Dental Caries / Q000382:microbiology / Q000473:pathology / Q000628:therapy*; D003793:Dental Restoration, Permanent / Q000379:methods*; D005899:Glass Ionomer Cements / Q000627:therapeutic use*; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D013295:Streptococcus mutans
chemical_list: D005899:Glass Ionomer Cements