COMPARISON OF CORONAL MICROLEAKAGE OF CAST POST AND CORE, CEMENTED WITH CONVENTIONAL GLASS IONOMER CEMENT AND GLASS IONOMER CEMENT INCORPORATED WITH NANO-HYDROXYAPATITE PARTICLES: AN IN VITRO STUDY

Statement of Problem: Microleakage is one of the major factors that determine the longevity of xed restoration. The type of luting agent used for cementation of post plays an important role in preventing bacterial microleakage. Purpose: To evaluate coronal microleakage of teeth restored with cast post and core cemented with conventional glass ionomer cement and nanohydroxyapatite incorporated glass ionomer cement. Materials and Method: 30 extracted single canal premolars were selected and endodontically treated by step-back technique, followed by obturation with gutta percha using zinc oxide eugenol sealer. Post space was prepared leaving 4mm of apical gutta percha and direct acrylic resin pattern of the root canal was made along with a core, with the help of pinjet system. This was then casted using cobalt-chromium alloy. The specimens were divided into 2 groups in which castings will be cemented using: Group 1, Conventional Glass Ionomer Cement; Group 2, Nano Hydroxyapatite incorporated Glass Ionomer Cement (6 wt%) Cemented teeth were stored in distilled water for 7 days and then immersed in silver nitrate dye for 6 hours followed by photochemical developing solution for 12 hours and nally sectioned into two halves mesiodistally. The degree of linear dye penetration into the coronal part of the specimens at dentin/cement interface was measured using a stereomicroscope at 20x magnication. Result: Coronal microleakage of cast post and core at tooth-cement interface, cemented with glass ionomer cement incorporated with 6% by weight of 80-100nm nano-hydroxyapatite particles and conventional glass ionomer cement were statistically signicant different with p = 0.015 by independent t test. The mean ± SD of conventional GIC was 2.47±0.74 and for nano-hydroxyapatite incorporated GIC was 1.73±0.80. Conclusion: Within the limitations of this study, it is concluded that the coronal microleakage of cast post and core at tooth-cement interface, cemented with glass ionomer cement incorporated with 6% by weight of 80-100nm nano-hydroxyapatite particles is less than that of conventional glass ionomer cement