Luting agent and abutment height effect on tensile bond strength of implant copings

Objectives: The purpose of this study was to evaluate the tensile bond strength (TBS) of implant copings cemented onto ITI solid abutments of varying heights (4.0, 5.5, 7.0 mm) using two permanent cements. Methods: Sixty high noble alloy copings (SF52) were fabricated using preformed plastic patterns - 20 of each height. Castings were air abraded with 50 micron aluminous oxide and cemented with zinc phosphate, ZP, (Flecks) or resin reinforced glass ionomer, RX, (Rely X). copings were cemented under a 20 N static load for 10 minutes and stored in 100% humidity at 37 degrees C for 48 hours. Tensile load was applied with a Zxick UTM using a 10 kN load cell at a crosshead speed of 5 mm/min. Force at tensile bond failure was recorded (Newtons). Results: Mean TBS for the groups (ranked highest to lowest) were : (ZP-5.5mm 497.79 N), (ZP-7.0 mm 471.01 N), (RX-4.0mm 427.71 N), (RX-7.0mm 368.34N), (ZP-4.0mm 343.39N), (RX-5.5mm 306.85N). Data were analyzed using non parametric rank-based regression methods. Multiple comparisons adjustment was made for all pairwise contrasts of treatment combination by the Tukey method. The two groups with the highest TBS (ZP-5.5mm and ZP-7.0mm) were significantly different from the three lowest TBS groups. In additions, TBS of RX-4.0mm differed significantly from TBS of RX-5.5mm. Conclusions: Under the conditions of this study, these data show combinations of cement and abutment height affected TBS of copings cemented to ITI abutments. This research was supported by The Straumann Company, Waltham, MA.