RESUMEN
INTRODUCTION: Orthodontists are commonly faced with the decision of what to do with loose brackets, and with inaccurately located brackets that need repositioning during treatment. One solution is to recycle the brackets. The potential effects of reconditioning a bracket are dependent upon many factors which may result in physical changes like alteration in slot tolerance, which may influence sliding mechanics by affecting frictional resistance. AIM: To study and compare the dimensional changes in the bracket slot width and depth in reconditioned brackets from unused brackets under scanning electronic microscope and to study and compare any consequent effects on the static frictional resistance of stainless steel brackets after reconditioning and in unused brackets. MATERIALS AND METHODS: Dentarum manufactured 90 stainless steel central incisors edgewise brackets of size 0.22 X 0.030â³ inch and 0° tip and 0°angulation were taken. 60 samples for measuring frictional resistance and 30 samples for measuring slot dimensions. Ortho organizers manufactured stainless steel arch wires 0.019 X 0.025â³ straight lengths 60 in number were considered for measuring static frictional resistance. RESULTS: The mean slot width and depth of new brackets were 0.0251â³ and 0.0471â³, which exceeded the manufacturers reported nominal size of 0.022â³ X 0.030â³, by 0.003â³ and 0.017â³. The reconditioned brackets demonstrated a further increase in mean slot width and depth to 0.028â³ and 0.0518â³ that is by 0.0035â³ and 0.0047â³ which is statistically significant (p=0.001, 0.002). The mean static frictional forces of the reconditioned brackets was nearly similar to that of new brackets that is 0.3167N for reconditioned brackets and 0.2613 N for new brackets. CONCLUSION: Although the reconditioning process results in physical changes to bracket structure this does not appear to result in significant effect on ex-vivo static frictional resistance.