LAUSR

Aims: The purpose of this study was to evaluate the in vitro microleakage of new modified glass ionomer cement (GIC)-nanozirconia-silica-hydroxyapatite (GIC-nanoZrO2-SiO2-HA) hybrid material by comparing the depth of microleakage with conventional GIC (Fuji IX). Materials and Methods: Forty samples of standardized oval-shaped cavity preparation (4 mm × 3 mm × 2 mm) on buccal or lingual surfaces of freshly extracted human premolar and molar teeth were prepared. The samples were divided in two groups (n = 20) by simple random sampling method and restored with the new modified GIC-nanoZrO2-SiO2-HA hybrid material and Fuji IX (control), respectively; following the manufacturer's recommendations. All samples were then submitted to thermocycling (500 cycles at 5°C–55°C). The external surfaces of each tooth were coated with nail varnish except a 1 mm wide margin surrounding the restoration. Samples were then immersed in 2% methylene blue at room temperature for 24 h before rinsed under running water. Each sample was sectioned mesiodistally before microleakage evaluation was done using a stereomicroscope under × 20 magnifications and graded accordingly. Results: Differences in microleakage scores between materials were compared statistically using independent t-test. The new material shows significantly more microleakage compared to Fuji IX at P < 0.05. Conclusion: As conclusion, within the limitation of this study, the new modified GIC-nanoZrO2-SiO2-HA hybrid material was found to have more microleakage than conventional GIC.