Laser etching of enamel for bonding orthodontic brackets

Abstract

The aim of this study is to determine the optimum laser parameters to provide the maximum bonding strength with reference to conventional bonding technique for orthodontic braces. 1940 nm Thulium Fiber Laser was used in pulse mode and in two di erent parameters for enamel etching procedure. In addition, there is a control group which had conventional acid etching technique. Laser etching procedure was carried out by two di erent approaches: Lasing without cooling and with cooling. For the rst approach, according to the whitening of the enamel initiation, application time of laser irradiation was de ned for each laser parameters. For the second approach, in order to prevent damage on alive tissue, water spray and air pressure cooling was applied during lasing to limit pulp temperature to maximum 5:5 C which is the critical temperature. After the bonding of ceramic braces, they were debonded from the enamel surface using mechanical test machine. When the bonding strength of the braces were analyzed, it was observed that the mean bonding strength of both the etching without cooling group and etching with cooling group are signi cantly di erent from acid etched group (p<0.05, student t-test). SEM evaluations of etched surface with laser showed that surface morphologies were not similar with acid etching group.|Keywords : Laser, Etching, Bracket.