Microleakage evaluation of novel nano-hydroxyapatite-silica glass ionomer cement

Aims and Objectives: To analyze the microleakage of nano-hydroxyapatite-silica glass ionomer cement (nano-HA-SiO2-GIC) and compare it with conventional glass ionomer cement (cGIC). Materials and Methods: Twenty caries-free human premolar teeth were used. A standardized box-shaped class V cavity was prepared on the buccal surfaces at the cemento-enamel junction, with the occlusal margin (OM) set on enamel and gingival margin (GM) was placed on the cementum. Teeth were randomly assigned to two experimental groups of 10 teeth each and restored as follows: group 1, cGIC (Fuji IX) and group 2, nano-HA-SiO2 GIC. After 24h of immersion in distilled water, the teeth were thermocycled (500 cycles and 5 degrees C-55 degrees C). Following that, the teeth were placed in 2% methylene blue solution and stored at room temperature for 24h. The microleakage along the tooth-restoration interface was recorded. Independent sample t-test (two-tailed) was used to analyze the data. Results with P < 0.5 were considered statistically significant. Results: Microleakage in general was greater at GMs as compared to OMs for both the materials. Nano-HA-SiO2-GIC exhibited lower microleakage at occlusal level (0.2 0.42) as compared to cGIC (0.5 +/- 0.71), whereas, at GM nano-HA-SiO2-GIC displayed significantly less microleakage (2.7 +/- 0.67) compared to cGIC (3 +/- 0.00). Conclusion: Nano-HA-SiO2 glass ionomers showed less microleakage both at OMs and GMs compared to that at cGIC (Fuji IX).