Repair Strength and Bond Failure of Aged CAD/CAM Hybrid Ceramic after Different Surface Treatments

Abstract

Objective: investigating the effect of surface treatments on the repair of aged CAD/CAM hybrid ceramic by composite resin utilizing MSBS test.Methods: (Shofu HC) Hybrid ceramic and Nano-hybrid composite resin ( Tertric N-Ceram Ivoclar Vivadent) were used. CAD/CAM blocks were divided into four groups, Control group, Sand-blasting group , Bur grinding group, HF etching group. Composite resin was packed into holes of a rubber base cylinder mold made from heavy body rubber base impression material to accomdate the composite micro tubes prepared for the microshear test. Half of the specimens were tested right after 24 hrs on the universal testing machine and the other half were stored in artificial saliva at 37c for 6months then thermo-cycled for 5000 cycles. MSBS and fractographic analysis were used to evaluate the failure mode.Results: MSBS values were the highest at the sand-blasting groups and the lowest values were recorded in the control group. Aging caused decline in bond strengthConclusion: Surface treatments had positive effect on bond strength but Aging had a detrimental effect.