OBJECTIVE: To test the hypothesis that fluoride prophylactic agents do not affect the fracture strength and fracture morphology of the tie-wing complex of ceramic brackets. MATERIALS AND METHODS: The fracture strength of the distal incisal tie-wing of two polycrystalline brackets, Clarity and Mystique, and a monocrystalline bracket, Inspire, was measured after the brackets were exposed to either Prevident, Phos-flur gel, or distilled water (control). Scanning electron microscopy was used to qualitatively evaluate the tie-wing intact and fractured surfaces. RESULTS: A two-way analysis of variance and Fisher-Hayter post hoc test, alpha = .05, indicated a significant decrease in tie-wing fracture strength following both fluoride treatments when compared with the distilled water control only with the monocrystalline bracket. None of the bracket brands exhibited any qualitative differences in the tie-wing intact or fracture surfaces as a function of fluoride treatment. CONCLUSIONS: The hypothesis is rejected. Based on the results, using topical fluoride agents with monocrystalline brackets might be contraindicated because of increased tie-wing fracture susceptibility.
OBJECTIVE: To test the hypothesis that fluoride prophylactic agents do not affect the fracture strength and fracture morphology of the tie-wing complex of ceramic brackets. MATERIALS AND METHODS: The fracture strength of the distal incisal tie-wing of two polycrystalline brackets, Clarity and Mystique, and a monocrystalline bracket, Inspire, was measured after the brackets were exposed to either Prevident, Phos-flur gel, or distilled water (control). Scanning electron microscopy was used to qualitatively evaluate the tie-wing intact and fractured surfaces. RESULTS: A two-way analysis of variance and Fisher-Hayter post hoc test, alpha = .05, indicated a significant decrease in tie-wing fracture strength following both fluoride treatments when compared with the distilled water control only with the monocrystalline bracket. None of the bracket brands exhibited any qualitative differences in the tie-wing intact or fracture surfaces as a function of fluoride treatment. CONCLUSIONS: The hypothesis is rejected. Based on the results, using topical fluoride agents with monocrystalline brackets might be contraindicated because of increased tie-wing fracture susceptibility.