Microhardness of enamel adjacent to orthodontic brackets after CO2 laser irradiation and fluoride application.
This study evaluated the effectiveness of carbon dioxide (CO2) laser combined or not with fluoride application on the surface microhardness of enamel adjacent to orthodontic brackets. Fifteen human molars were selected from which 30 enamel fragments measuring 4 mm2 were obtained. The fragments were embedded in PCV tubes with acrylic resin and prepared using water abrasive paper, felt disks and alumina. Orthodontic brackets cut in half were bonded to enamel and 3 microhardness readings were performed on the adjacent surface, as follows: initial, after cariogenic challenge and final. The specimens were divided into the following 3 groups (n=10): Group C: control, Group L: irradiated with CO2 laser, and Group FL: topical fluoride application and CO2 laser irradiation. After initial reading, the specimens were placed in a demineralizing solution for 32 h and the second reading was to verify if demineralization was uniform in all groups. After the treatments, the specimens were submitted to DES-RE cycling for 8 days followed by final surface microhardness reading. The data were analyzed statistically using ANOVA and Duncan test (α=0.05). At the final measurement Group FL obtained higher microhardness value than Groups C and L (p<0.05). Groups L and FL were statistically superior to Group C (p<0.05). Irradiation with CO2 laser around orthodontic brackets combined or not with topical fluoride application was effective to increase the surface microhardness of enamel.
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Leonardo Pucci
LP
Stangler
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Fábio Lourenço
FL
Romano
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Mariana Umekita
MU
Shirozaki
Department of Dental Materials, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Rodrigo
R
Galo
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Alessandra Marques Correa
AM
Afonso
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Maria Cristina
MC
Borsatto
Department of Pediatric Clinic, Ribeirão Preto School of Dentistry, USP - University of São Paulo, Ribeirão PretoSP, Brazil.
Mírian Aiko Nakane
MA
Matsumoto
D002245:Carbon Dioxide; D003743:Dental Enamel; D005459:Fluorides / Q000008:administration & dosage*; D006245:Hardness Tests; D006801:Humans; D007834:Lasers; D008963:Molar; D016910:Orthodontic Brackets; D013499:Surface Properties
D002245:Carbon Dioxide; D005459:Fluorides