Evaluation of the Two-paste Resin-reinforced Glass-ionomer Cement for Cementation of Orthodontic Bands

The two-paste resin-reinforced glass ionomer for the placement of orthodontic bands has been developed for easier handling. Objective: the aim of this study was to evaluate the fluoride release characteristics. Methods: four fluoride-releasing glass ionomers were evaluated in this study, namely: two-paste resin-reinforced glass ionomer (FOB) (Fuji ORTHO BAND PASTE PAK, GC Corporation, Japan), powder/liquid type resin-reinforced glass ionomer (MBC) (Multi-Cure Glass Ionomer Orthodontic Band Cement, 3M Unitek, USA), polyacid-modified composite resin (UBL) (Ultra Band Lock, Reliance Orthodontic Products, USA), and conventional glass ionomer (KCM) (Ketac Cem, Espe-premier dental products, USA). All materials were prepared according to the respective manufacturers' instructions. Immediately after preparation of the materials, the cement was placed in an acrylic mold containing cylindrical hole 7 mm in diameter and 1.5 mm in depth. Twenty specimens were fabricated for each cement. After storage in the incubator for 30 minutes, a couple of specimens were placed in 8 ml of distilled water within a glass container. Initial fluoride release was assessed over a 4-week period for all materials by a fluoride electrode and an ion meter. Initial release was determined by frequent measurements over the first week: days 1, 2, 3, and 7. Weekly measurements were then made up until the time of fluoride exposure. Results: All the evaluated materials released fluoride with considerable variation in the rate of release. Since repeated measures ANOVA indicated a significant difference, Scheffe pairwise comparison was carried out to identify statistical significance between any two means. FOB released significantly higher amount of fluoride than KCM, MBC and UBL. UBL showed the lowest initial fluoride release and continued to show the lowest value throughout the study. Scheffe pairwise comparison showed significant differences among the four materials. Conclusion: The two-paste resin-reinforced glass ionomer cement releases more fluoride than conventional cement (KCM, MBC, UBL).