COMPARISON OF CUSPAL DEFLECTION & MICROLEAKAGE IN CLASS II RESTORATION WITH DIFFERENT MATERIALS: AN INVITRO STUDY

Aim & objective: To compare the cuspal deflection and microleakage in class II restoration with Nanocomposite,Bulkfill composite resin & new hybrid GIC cement. Materials and Methods: Freshly extracted human maxillary 1st premolar teeth were collected ((n=30).Samples were embedded 3mm beneath the CEJ in selfcure acrylic resin block.Small glass beads were fixed with X-Flow resin on the cusps as reference point.Buccopalatal width was measured with a Digital Micrometer Gauge before prepartion.Standardized Class II MOD cavities prepared on all the samples in dimensions:2mm width x 2mm axial depth x 2mm depth. Samples were divided into groups according to restoration done:GroupA: Nanocomposite(Filtek Z350 XT),Group B:Bulk fill composite(FiltekBulkfill), Group C:Hybird GIC cement.Bucco palatal width were measured after restoration and after thermal cycling(500cycle) to measure cuspal deflection then immersed in 2 % methylene blue dye for 24 hours.The samples were sectioned vertically(mesiodistally) and dye penetration were recorded under a stereomicroscope(20X) using a scoring system. Results: The mean Bucco-Palatal width of cusp decreased after restoration and after thermocycling as compared to before restoration in group A&C but in Group B increases after restoration & after thermal cyclinig.The mean dye penetration of Group-A (1.90±1.10) followed by Group-C (1.80±0.79) were higher than that of Group-B (1.60±0.70) but one-way analysis of variance (ANOVA) showed that there was no significant difference between them. Conclusion: Nanocomposite, bulkfill composite and GIC hybrid cement causes cuspal deflection and microleakage on the MOD cavities, though not statistically significant.