In-vitro fluoride release rates from 9 orthodontic bonding adhesives

The purpose of this study was to compare the in-vitro fluoride release rates from 9 orthodontic adhesives in distilled water.

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.

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.

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.