title: Evaluation of carbon dioxide laser irradiation associated with calcium hydroxide in the treatment of dentinal hypersensitivity. A preliminary study.
abstract: Attempts have been made to treat dentinal hypersensitivity by sealing exposed dentinal tubules, and the carbon dioxide (CO(2)) laser has been shown to have a sealing effect on dentinal surfaces. The purpose of this study was to analyze the morphological ultra-structure and temperature change after CO(2) laser irradiation of dentin. Fourteen human third molars were selected and cleaned. An area was delimited, and the samples were randomly divided into seven groups: Group 1 (G1): control; G2, calcium hydroxide paste (CA) + CO(2) laser (L) (0.5 W/63,69 W/cm(2)); G3, CA + L (1 W/125,38 W/cm(2)); G4, CA + L (1.5 W/191,08 W/cm(2)); G5, L (0.5 W); G6, L (1 W); G7, L (1.5 W). All irradiation was performed in unfocused mode. The electron micrographs were analyzed by three observers. For temperature analysis, a thermocouple was used. Data were subjected to statistical analysis. The Kruskal-Wallis non-parametric test showed statistical differences between the groups (P < 0.05). For the two by two comparisons, all groups treated with calcium hydroxide paste presented significantly higher mean scores. In the groups treated by CO(2) laser only, fusion, re-crystallization, cracks and carbonization were observed. A change of 1 ± 5°C was noted in the temperature. Under the limitation of an in vitro study, and with the protocols used, we concluded that CO(2) laser is safe to use for the establishment of partial fusion and re-solidification of the dentinal surface.
authors.affiliation: Lasers in Dentistry, School of Dentistry, University of São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Ana Cristina Cury Camargo
authors.initials: AC
authors.lastname: Romano
authors.forename: Ana Cecilia Corrêa
authors.initials: AC
authors.lastname: Aranha
authors.forename: Bruno Lopes
authors.initials: BL
authors.lastname: da Silveira
authors.forename: Sônia Lícia
authors.initials: SL
authors.lastname: Baldochi
authors.forename: Carlos de Paula
authors.initials: Cde P
authors.lastname: Eduardo
mesh_terms: D002126:Calcium Hydroxide / Q000008:administration & dosage*; D003807:Dentin Sensitivity / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D054020:Lasers, Gas / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D008855:Microscopy, Electron, Scanning; D009824:Ointments; D013696:Temperature
chemical_list: D009824:Ointments; D002126:Calcium Hydroxide