Comparative Evaluation of bond strength of Experimental Shock-Absorbing Dental Cement for implant supported restorations

Abstract

Aim. Compare bond strength of experimental shock-absorbing cement with conventional cements used to cement implant-supported restorations. Materials and Methods. A total of 42 samples divided into 2 groups; Gp (A): one-piece Titanium implant analogues (n=21) of 0.5mm finish line, 5.5mm height and 6˚ taper were centrally and vertically mounted in transparent acrylic resin blocks. Each analog received Co-Cr coping including a 4mm Ø occlusal loop. Gp(B); Titanium and Co-Cr plates (n=21 each) 8x8x3mm and 6x6x3mm respectively were constructed. Subgroups 1,2,3 according to type of cement used; A1 and B1 glass ionomer, A2 and B2 resin cement, A3 and B3 Medical grade silicone adhesive. Samples were thermocycled 1000 cycles, collected, dried and tested. Tensile and shear bond strength were carried out using universal testing machine, at 0.5mm/min speed. Debonding forces were recorded and statistically analyzed. Failure modes were inspected. Results: Mean ± SD recorded in tension were highest for Resin cement SubGp A2 (79.18±18.5 N), then medical grade Silicone SubGp A3 at (71.367±14.896 N), lowest was with SubGp A1 GI cement (41.165±9.73 N). Mean ± SD in Shear were highest for Resin cement SubGp B2 (3.067±0.895 MPa), then medical grade Silicone SubGp B3 (1.844±0.308 MPa), lowest was with SubGp B1 GI (1.073±0.631 MPa). T-student test revealed significant difference between tested groups (P=0.001). Conclusion: Experimental medical grade silicone cement showed better mean tensile and shear bond strengths than Glass ionomer cement and lower than that of resin cement, therefore it could present a reliable option for cementing implant supported prosthesis.