title: In vitro study of the effect of Er:YAG laser irradiation on the apical sealing of different root canal sealers.
abstract: OBJECTIVE
  The aim of this study was to determine the effect of Er:YAG laser irradiation used to clean dentinal walls on the apical sealing of root canals filled with different types of sealers.
  
  
  BACKGROUND
  Laser application to the dentinal walls removed debris, rendering the root canals free of smear layers and leaving the dentinal canaliculi open.
  
  
  METHODS
  Sixty-four maxillary canines obtained from laboratory files were instrumented with K-files (Dentsply, Maillefer, Ballaigues, Switzerland) using the crown-down technique, and irrigated with a 0.5% sodium hypochlorite solution. The specimens were divided into two groups of 32 teeth each. In group I, the teeth were instrumented and irrigated with sodium hypochlorite solution, and divided into four subgroups to be sealed with the different materials (Endofill, N-Rickert, Sealapex and Sealer 26). In group II, the root canals were subjected to Er:YAG laser irradiation (200 mJ, 7 Hz and 60 J total energy), followed by root canal sealing as in group I.
  
  
  RESULTS
  The data showed lower levels of apical microleakage in the teeth filled with N-Rickert, Sealapex and Sealer 26 cements than in those sealed with Endofill (p < 0.01). No significant difference in microleakage was observed between teeth irrigated only with 0.5% sodium hypochlorite and those submitted to Er:YAG laser application (p > 0.05).
  
  
  CONCLUSIONS
  The Er:YAG laser irradiation applied to the root canal walls was not able to prevent apical microleakage.
authors.affiliation: Dental School, University of Ribeirão Preto (UNAERP), Ribeirão Preto, SP, Brazil.
authors.forename: Fernanda Vieira
authors.initials: FV
authors.lastname: Medina
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: Souza-Neto
authors.forename: Jacy Ribeiro
authors.initials: JR
authors.lastname: Carvalho-Junior
authors.forename: Heid Sueli Leme
authors.initials: HS
authors.lastname: dos Santos
authors.forename: Melissa Albanese
authors.initials: MA
authors.lastname: Mezzena
authors.forename: Lucas da Fonseca Roberti
authors.initials: Lda F
authors.lastname: Garcia