Comparison of Surface Topography Changes from Conventional Metal Brackets and Self-Ligating Metal Brackets after Immersion in Three Different Mouthwashes using Atomic Force Microscopy: An in vitro Study.

In orthodontics, the surface roughness and corrosion behavior due to metal ion releases in orthodontic brackets and archwires affect the effectiveness of tooth movement. Atomic force microscopy (AFM) can provide three-dimensional information measurements which are used to evaluate the quantitative analysis of the surface changes of orthodontic brackets. Stainless steel orthodontic brackets and wires can release metal ions which lead to corrosion when exposed to various types of mouthwash. Aim: The main aim of this study is to compare and evaluate the surface changes from conventional metal brackets and self-ligating metal brackets after immersion in three different mouthwashes. Materials and Methods: Sixteen conventional metal brackets and sixteen metal self-ligating brackets were evenly grouped and immersed in deionized water, chlorhexidine mouthwash, herbal mouthwash, and betadine mouthwash for seven days and the surface changes were evaluated using nondestructive AFM. Results: The surface roughness was evaluated at 30 µm and the results showed that more surface roughness was observed P < 0.05 in betadine mouthwash groups and followed by herbal mouthwash and least in chlorhexidine mouthwash. Conclusion: Based on the AFM results, the surface changes were more pronounced in both groups which were immersed in betadine and herbal mouthwash than others and the choice of mouthwash should be considered before prescribing to the patients.

Effect of ER, CR: YSGG laser debonding on enamel surface changes in stainless steel and ceramic brackets - An in-vitro study.

AIM: The aim of this in-vitro study was to observe and analyze the various enamel surface changes that occur due to laser debonding of metal and ceramic brackets, done by means of Er, Cr:YSGG laser. MATERIALS AND METHODS: 90 extracted premolars were randomly allocated into one of six groups with 15 teeth each. The groups represent metal brackets (Groups A1, A2, A3) and ceramic brackets (Groups B1, B2, B3). Each sub-group represents the mode of debonding used in the study. Debonded teeth were analyzed under scanning electron microscopy (SEM) at 80X and at 1000X magnification at three sites. The adhesive remnant index (ARI) scores were analyzed and the presence of enamel damage was observed. RESULT: ARI showed high score in Groups A1 and B1. SEM images of large composite remnants at the site of bracket in Groups A1 and B1 at the site of bracket and multiple enamel microcracks and fractures at interface and enamel adjacent to bracket in Groups A1 and B1. SEM images of minimal composite remnants at the site of bracket in Groups A2, A3, B2, and B3 and little to no presence of enamel microcracks or fractures at interface and enamel adjacent to bracket in Groups A2, A3, B2, and B3. CONCLUSION: The use of Er, Cr:YSGG laser in orthodontic practice, especially in the debonding procedures of orthodontic brackets provide quality care to patient with minimal post-treatment damages.