Microleakage under orthodontic bands cemented with nano-hydroxyapatite-modified glass ionomer An in vivo study

Objectives: To estimate the in vivo effect of nano-hydroxyapatite (HA) modification of banding glass-ionomer cement on microleakage under orthodontic bands. Materials and Methods: Eighty noncarious premolars scheduled for extraction in 20 orthodontic patients were randomly divided into four groups. Grouping was based on the ratio of nano-HA (0%, 5%, 10%, 15% by weight) added to the luting glass-ionomer cement (GIC) Ketac-Cem, which was used for cementation of prefabricated micro-etched orthodontic bands. Dye penetration method was used for microleakage evaluation at the cement-band and cement-enamel interfaces. Statistical evaluation was performed with a Kruskal-Wallis test and a Mann-Whitney U-test, and a Bonferroni-adjusted significance level was calculated. Results: Bands cemented with conventional GIC showed the highest microleakage scores in comparison to those cemented with nano-HA-modified GIG. No significant difference was found between teeth banded with 10% and 15% modified GIC. Conclusions: Modification of the banding GIG with 15% nano-HA revealed a positive effect on reducing microleakage around orthodontic bands.