MICROLEAKAGE AND SHEAR BOND STRENGTH EVALUATION OF ZIRCONIA REINFORCED GLASS IONOMER RESTORATIVE IN PRIMARY MOLARS (IN VITRO STUDY)

INTRODUCTION There has been continuous interest by researchers to improve the biomechanical properties of glass ionomer cements (GICs). The inclusion of zirconia fillers in the glass component of GICs developed a high strength restorative material known as Zirconomer Improved (ZI). (1) The success of this new restorative material depends on its marginal seal and good adhesion with tooth dentinal surfaces. (2) The study aimed to evaluate in vitro, the microleakage and dentin shear bond strength (SBS) of zirconia reinforced glass ionomer restorative ZI compared to resin modified glass ionomer cement (RMGIC) (Fuji II LC) in restoration of primary molars. METHODOLOGY A total of twenty-eight primary molars were included in the study. The teeth were allocated randomly into four equal groups (n=7) according to the evaluation method and type of applied GIC. For microleakage test, standardized class v cavities were prepared on the buccal surfaces of each molar. In group I (test) ZI was applied, while in group II (control) RMGIC was applied. Specimens were thermocycled for 500 cycles, immersed into methylene blue dye for 24 hours, sectioned and examined under a stereomicroscope. (3) Quantitative assessment was done by recording the distance of stain penetration at gingival and occlusal margins. It was assessed as percentage based on the following formula: Microleakage percentage % = depth of dye penetration (mm) / cavity depth (mm) x 100. (4)