A comparative analysis of the amount of fluoride release, recharge and re-release after uptake in three light-cure orthodontic bonding adhesives – An in-vitro study

Background: Fluoride-releasing adhesives in orthodontics help protect enamel. The study compared the fluoride release, recharge, and re-release properties of three light-cure orthodontic bonding adhesives: Group A: Transbond ^TM Plus Color Change, Group B: Waldent Orthobond LC, and Group C: Koden EZ Bond. Methods: The study conducted an in-vitro investigation using 24 maxillary first premolar teeth bonded with one of three fluoride-releasing adhesives after etching. Each sample was placed in artificial saliva, and fluoride release was measured over 60 days using a fluoride electrode. After initial release measurement, specimens were soaked in 1000 ppm fluoride solution for 5 minutes, rinsed, and placed in new containers with distilled water before re-release measurements. Statistical Analysis: One-way ANOVA and Repeated Measures ANOVA tests were used to determine significance, with the Bonferroni posthoc test for further analysis. Results: The fluoride release rate decreased gradually over time for all three groups. The highest fluoride release occurred on Day 1 for all three bonding agents, with a significantly reduced fluoride release by Day 2. Group A exhibited consistent and highest overall fluoride release throughout the 60 days. Group B gradually declined to release fluoride until Day 7, releasing the least fluoride throughout the study. Group C had a higher fluoride release on Day 1 and Day 2 but slowly declined until Day 14. Group B and Group C sharply declined fluoride release by Day 30 and almost negligible amounts on Day 60. All three agents noted enhanced fluoride release post-recharge, with continuous release until day 14. Greater release on days 7 and 14 compared to the initial release in all three groups. Conclusion: Transbond Plus Color Change: Consistent high fluoride was released initially and post-recharge. Waldent Orthobond LC: Lower release throughout the study. Koden EZ Bond: High initial release and post-recharge but continuing to decrease until Day 14.