COMPARISON OF LOAD DEFLECTION PROPERTIES AND FRICTIONAL RESISTANCE OF CONVENTIONAL NITI ARCHWIRES AND COATED NITI ARCHWIRES GENERATED IN VARIOUS CERAMIC BRACKET SLOTS - AN IN - VITRO STUDY

Introduction:-Two main groups of materials used in fixed orthodontics are brackets and archwires. The present study was done to compare the frictional resistance and load-deflection properties of conventional NiTi archwire, Teflon coated NiTi archwire and Epoxy resin coated NiTi archwire when placed within the slot of ceramic brackets, metal-insert ceramic brackets and self- ligating ceramic brackets. Method: The frictional resistance (static friction and kinetic friction) and load-deflection properties (loading and unloading forces) of conventional NiTi, Teflon coated NiTi and Epoxy resin coated NiTi archwires (0.019x0.025) were evaluated when placed within the slot of ceramic bracket, ceramic bracket with metal slot and ceramic self ligating bracket (0.022x0.028 MBT prescription). 54 samples were tested (6 per group) using Universal Testing Machine. Results: Least static and kinetic friction was found when Epoxy resin coated NiTi wire was used with ceramic self ligating bracket. Highest static friction was found when Teflon coated NiTi wire was used with ceramic self ligating bracket. Least loading and unloading forces were found when Epoxy resin coated NiTi wire was used with ceramic self ligating bracket. Highest loading and unloading forces were found when Teflon coated NiTi was wire used with ceramic bracket. Conclusion: Epoxy resin coated archwire showed had more potential to reduce the friction and produced less loading and unloading forces as compared to Teflon coated archwire and conventional NiTi arch wire. Ceramic self ligating brackets and ceramic brackets with metal slot produced low frictional forces as compared to conventional ceramic brackets.