title: Assessment of thermal alteration during class V cavity preparation using the Er:YAG laser.
abstract: OBJECTIVE
  The aim of this study was to evaluate in vitro the pulp thermal alterations during class V cavity preparations using the Er:YAG laser and high-speed water flow.
  
  
  METHODS
  Forty human teeth were selected and prepared for the thermocouple adaptation in the pulp chamber. The specimens were assigned to four groups: (1) laser 300 mJ/3 Hz, (2) laser 300 mJ/4 Hz, (3) high-speed 9 mL/min water flow, and (4) high-speed 100 mL/min water flow. The temperature was measured before the beginning and at the end of the preparation, as well as during the procedures. The groups were analyzed by scanning electron microscopy.
  
  
  RESULTS
  Data analysis disclosed temperature reduction at high-speed drilling with the high-speed total water flow group, and these values were statistically different from the other groups. The results of the 9-mL/min water flow group were similar to those of the 300-mJ/3-Hz group and different from the 300-mJ/4-Hz laser group.
  
  
  CONCLUSIONS
  The laser promoted a greater increase in temperature only when compared with high-speed handpiece and water flow rate of 100 mL/min.
authors.affiliation: Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto-SP, Brazil.
authors.forename: Walter
authors.initials: W
authors.lastname: Raucci-Neto
authors.forename: Larissa M S
authors.initials: LM
authors.lastname: De Castro
authors.forename: Alessandra M
authors.initials: AM
authors.lastname: Corrêa-Afonso
authors.forename: Reginaldo S
authors.initials: RS
authors.lastname: Da Silva
authors.forename: Jesus D
authors.initials: JD
authors.lastname: Pécora
authors.forename: Regina G
authors.initials: RG
authors.lastname: Palma-Dibb
mesh_terms: D001831:Body Temperature / Q000528:radiation effects*; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003782:Dental Pulp / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D008855:Microscopy, Electron, Scanning; D018709:Statistics, Nonparametric