Effect on Bracket Bonding of Polishing with Fluoride-Containing Prophy Paste Before Enamel Pretreatment with Orthophosphoric Acid: A Randomized Clinical Trial

Objective: This randomized clinical trial assessed the effects of polishing enamel with fluoride prophy paste before enamel pretreatment with orthophosphoric acid on bracket bond outcomes. Methods: The study included 49 patients with a mean age of 24.6 years. Participants were randomly allocated to two groups in an approximate 1:1 ratio: 25 participants in the fluoride group (Group 1) and 24 in the non-fluoride group (Group 2). All patients' tooth surfaces were polished with prophy paste, etched, and fitted with brackets. Patients were followed up for 6 months. Outcome measures included bracket bond survival and the number of bond failures, along with questionnaire items collected from all subjects, such as history of fluoride varnish and mouthwash use, age, and sex. Survival time analysis was used to characterize bond failure outcomes. Results: A total of 951 brackets were tested; the overall bond failure rate was 2.7%. Group 2 (non-fluoride polishing) had a bond failure rate of 4.0%, while Group 1 (fluoride polishing) had a significantly lower failure rate of 1.5%. These failure rates were much lower than those reported previously. Survival analysis, accounting for patient-level variability through random effects, revealed that age and fluoride prophy paste were significant risk factors. The hazard ratio for bond failure associated with the use of fluoride-containing prophy paste was 0.26. Conclusion: Polishing with fluoride-containing prophy paste did not affect the bracket-bond failure rate when it was followed by phosphoric acid etching.