الفهرس | Only 14 pages are availabe for public view |
Abstract Summary and Conclusion In the current study Er:YAG and Er,Cr:YSGG were used for debonding of polycrystalline ceramic brackets and their effect on adhesive remnant index (ARI) and enamel surface roughness (ESR) were evaluated and compared to the conventional debonding method. Sixty polycrystalline ceramic brackets were bonded to 60 premolars extracted for orthodontic purposes. The teeth were divided into 3 groups. The first group was considered as the control group and no laser application was performed. The other two groups were considered as test groups and laser application was performed. group 1: consisted of 12 premolars that were debonded with a debonding plier. group 2: consisted of 24 premolars that were debonded with Er,Cr:YSGG laser and was divided into two subgroups 12 brackets in each: group 2A: The samples were irradiated with Er,Cr:YSGG laser at power 9 W. group 2B: The samples were irradiated with Er,Cr:YSGG laser at power 6 W. Summary and Conclusion 55 group 3: consisted of 24 premolars that were debonded with Er:YAG laser and was divided into two subgroups, 12 brackets in each: group 3A: The samples were irradiated with Er:YAG laser at power 9 W. group 3B: The samples were irradiated with Er:YAG laser at power 6 W. The debonded samples were evaluated by scanning electron microscope (SEM) at 20x magnification to assess the ARI score. The ARI score classification was: - 0, No adhesive remained on the enamel surface. - 1, Less than half of the adhesive remained on the tooth surface. - 2, More than half of the adhesive remained on the tooth surface. - 3, All the adhesive remained on the tooth surface. After removing all the adhesive remnants at the site of debonding in all groups with a tungsten carbide bur at high speed followed by polishing with pumice and polishing brush at low speed, enamel surface roughness was evaluated by SEM at 60x magnifications. The micrographs were interpreted and classified according into the following: - 0, Enamel surface free from cracks or tear-outs (no damage). - 1, Enamel surface with cracks. - 2, Enamel surface with tear-outs. - 3, Enamel surface with cracks and tear-outs. Summary and Conclusion 56 Within the limitations of the current study, the following was concluded: 1. Under the inquired parameters, both Er,Cr:YSGG and Er:YAG lasers can effectively debond polycrystalline ceramic brackets without using any additional forces. 2. Using of Er,Cr:YSGG laser at 9W can decrease the chairside time for ceramic brackets debonding by decreasing the need for post-debond enamel finishing. 3. Both Er,Cr:YSGG and Er:YAG laser debonding decreases the risk of enamel damage compared to the conventional method |