In-vitro fluoride release rates from 9 orthodontic bonding adhesives

INTRODUCTION: The purpose of this study was to compare the in-vitro fluoride release rates from 9 orthodontic adhesives in distilled water. METHODS: Of the adhesives tested, 4 were bracket bonding agents (Fuji Ortho LC [GC, Leuven, Belgium], Enlight LV [Ormco, Glendora, Calif], ConTec LC [Dentaurum, Ispringen, Germany], and Transbond XT [3M Unitek, Monrovia, Calif]); the remaining 5 were molar banding cements: Fuji Ortho Band Paste Pak (GC), OptiBand (Ormco), GlasTec (Dentaurum), Multi-Cure (3M Unitek), and Transbond Plus (3M Unitek). Ten samples of each adhesive were stored in containers holding 5 mL of deionized distilled water at 37 degrees C. Fluoride release was measured with an ion-specific electrode (model 96-09BN, Orion Research, Beverly, Mass). Readings were taken periodically for a total time period of 3 months. Descriptive statistics were calculated for the fluoride release rates of each material group. The data were subjected to a general linear regression model to detect differences in fluoride ion concentration by material and time. Post-hoc test with the Bonferroni adjustment was used to further delineate group differences. RESULTS: Among the bracket bonding adhesives, statistically significant differences were found in fluoride release rates (P = .000), with Fuji Ortho LC releasing the most fluoride. Enlight LV, ConTec LC, and Transbond XT released negligible amounts of fluoride. Fuji Ortho Band Paste Pak released more fluoride (P = .000) than all remaining molar banding adhesives. Multi-Cure released more fluoride than GlasTec, Transbond Plus, and Optiband. The latter released negligible amounts of fluoride. CONCLUSIONS: Fuji Ortho Band Paste Pak released more fluoride than the other adhesives. Fuji Ortho Band Paste Pak and Fuji Ortho LC might have sufficient fluoride-release rates to reduce white spot formation, and they are recommended as suitable fluoride-releasing orthodontic adhesives.