COMPARATIVE EVALUATION OF THE SURFACE MORPHOLOGY OF METAL BRACKETS SLOT BEFORE AND AFTER THEIR USE IN THE ORAL CAVITY USING SCANNING ELECTRON MICROSCOPE(SEM):AN EX-VIVO STUDY

Introduction: The oral medium and time can influence the physical-chemical properties of stainless steel brackets andthis will influences the corrosion behaviour and biocompatibility of the material.This study is aimed to evaluate and compare the surface roughness of maxillary canine metal brackets slot floor before and after its use in the oral cavity using SEM. Aim: To evaluate and compare the surface roughness of right and left maxillary canine metal brackets slot floor (0.022 MBT prescriptions of 3M Unitek Gemini series), before and after its use in the oral cavity using SEM. Materials and methods: The control group (GROUP I) consisting of 5 right and 5 left as-received brackets of 0.022 MBT and experimental group (GROUP II) consisted of 15 orthodontic patients who were undergoing orthodontic treatment with the extraction of upper first premolar teeth which consists of 30 brackets of 0.022 MBT prescription (15 right canines and 15 left canines). After 6 to 8 months of alignment and individual canine retraction analysis grid was formed in images and evaluation of craters were done according to three categories (mild: <= 4mm), (moderate: 5 to 10 mm) and (severe: >= 10mm). Result:In all magnifications, surface roughness (mild craters)was significantly higher in as-received brackets (Group I) when compared to experimental group (Group II). In all magnifications surface roughness (moderate and severe craters) is significantly higher in experimental group when compared to control group. Conclusion: There is increase in surface roughness of bracket slot floor in the experimental group when compared to control group. Orthodontic brackets show signs of degradation such as morphologic changes, surface alterations from corrosion, and wear and release of elements into the oral environment.