Porcelain surface evaluation after debonding of orthodontic brackets

André Moreira MATTOS, Jonas CAPELLI JÚNIOR

Aim: the aim of this study was to evaluate the influence of acid conditioning time in porcelain surface and its characteristics after debonding of orthodontic brackets. Methods: twenty samples of feldspathic porcelain for enamel (Duceram-LFC) were divided in 2 groups according with the amount of time of acid conditioning with hydrofluoric acid 10% (15 seconds and 1 minute). After acid etching, it was applied silane (3M Scotchbond), adhesive (Optibond Solo Plus) and resin (Fill Magic) in these surfaces. The debonding was done with shear strength through a universal testing machine (DL 500 – EMIC) calibrated with a fixed speed of 0.5mm/minute. The adhesive remnant index (ARI) in the porcelain surfaces and their characteristics after removal of the brackets were evaluated through digital pictures. Results: in the 15 seconds group, the mean bond strength was 3.63Mpa, significantly lower than the 1 minute group, that was 7.18Mpa (p<0.0001). All fractures during debonding were cohesive in the composite resin layer (70%) or bond between the bracket and the resin (30%). In relation to the ARI analysis, the Chi-square test showed no statistically significant difference between both groups. Conclusion: conditioning with hydrofluoric acid 10% for 1 minute, followed by the application of silane, adhesive and resin was considered the best porcelain preparation method before orthodontic bonding.

Keywords: Hydrofluoric acid. Porcelain. Brackets. Bonding.

Saturday, December 28, 2024 22:49