Cementation of vented crowns with low deformation

Crown deformation during cementation was measured with a circumferential strain gauge. The effects of different seating forces (3, 10 and 25 N), three different cements (Phosphacap, Ketac-cem Applicap and Fuji-cap I) and the presence or absence of venting on deformation and seating discrepancy were investigated. Forty microns of cement space was provided for all experiments. Venting increased deformation and reduced seating discrepancy, whilst increased force increased deformation and decreased seating discrepancy. Ketac-cem Applicap allowed the lowest seating discrepancy with median crown deformation. It was possible, by using venting, low forces (10 N) and Ketac-cem Applicap, to achieve a low marginal discrepancy with low crown deformation. Venting also diminished the seating discrepancy to acceptable levels when higher forces (25 N) were used with Phosphacap.