Effect of Er,Cr

Abstract

Bracket dislodgement during orthodontic treatment is an undesirable but common event. the aim of the present study was to investigate the effect of Er, Cr:YSGG laser application on selective ommition of bonded composite on ceramic brackets and to compare shear rebonding strength of failed ceramic brackets and bonding strength of new brackets. Materials and methods: Sixty caries free human premolars were mounted on cylinders filled with self-cured acrylic. Thirty one ceramic brackets were bonded on the teeth. shear bond strength of brackets were measured using hounsfield test equipment. The bracket bases were irradiated using Er,Cr,YSGG laser in order to ommit composite remnants on them. Then the brackets rebonded on fresh teeth, thermocycled, and shear bond strength of teeth were measured. The samples were evaluated under stereomicroscope and debonding pattern was recorded using ARI score. Statistical anahysis was done using SPSS software (ver.19) using independent T-test, Chi-squre and Fisher's exact test. Result: Mean shear bond strength of bond andrebond groups were 12.29+-5.46 and 10.58+-5.16 MPa accordingly, and there was not statistically significant difference between them (p=0.21). Also debonding pattern of two groups were not ststistically different(p=1.0). conclusion: Er, Cr:YSGG laser was effective in ellimination of adhesive remnants from ceramic brackets and this method can also be considerd as an effective procedure in rebonding debonded ceramic brackets.