In-vitro investigation of the effect of different resin removal methods on the enamel surface

This study aims to investigate the surface roughness of enamel after removal of orthodontic adhesive with different debonding techniques. A total of 60 teeth, consisting of 6 groups, were used in this study. The roughness quantitative measurements of the enamel surfaces of untreated teeth in the first phase of the study were analyzed with an optical profilometer. For qualitative evaluation, images were taken by scanning electron microscope at 3 random teeth from each group. After the initial roughness analysis was completed, the bonding of the adhesive resin to the surface of the teeth was performed and all specimens were subjected to 10,000 thermal cycles between 55°C and 5°C. Subsequently, the adhesive resin on the surface of the enamel was cleaned with 6 different methods and the time spent for each procedure was recorded. A total of 60 human premolars were selected and divided into six groups according to the method used for adhesive remnant removal: 6 blade tungsten carbide bur at high speed (1.group, 6A), 6 blade tungsten carbide bur at 20.000 rpm (2. Group, 6M20), 6 blade tungsten carbide bur at 40.000 rpm (3. Group, 6M40), 12 blade tungsten carbide bur at high speed (4.group, 12A), 12 blade tungsten carbide bur at 20.000 rpm (5. Group, 12M20), 12 blade tungsten carbide bur at 40.000 rpm (6. Group, 12M40), After cleaning the adhesive resin, the second and final roughness measurements of the enamel surfaces of the teeth were analyzed with a profilometer. The images of the teeth that were previously imaged by scanning electron microscope were obtained for the second time. The enamel surface roughness increased significantly in all groups after the resin removal process. The roughness increase of the 6M40 is highest. For the Ra parameter, the increase in surface roughness of the 12A was not significant. For Rq, Rt and Rz parameters, the increase in surface roughness of 12A and 12M20 was not significant. Removing the adhesive remnant with 6 blade tungsten carbide bur at 20.000 rpm is the most time-consuming method. There is no correlation between time and the roughness parameters. A method that does not cause damage to the enamel surface has not been achieved. Careful use of 12 blades of tungsten carbide bur at high speed with an aerator is recommended. The use of 6 blades of carbide bur with micromotor at 40,000 rpm is not recommended because it causes permanent damage on enamel surface.