tensile bond strength of three custommade tooth-colored implant superstructures to titanium inserts

Statement of the problem: hybrid abutments are made of a titanium implant insert and a ceramic component. the tensile bond strength between the titanium implant insert and the ceramic component is not still clearly known.purpose: this in vitro study aimed to compare the tensile bond strength of the titanium insert to ceramic components made of milled lithium disilicate, milled zirconia, and pressable lithium disilicate.materials and method: to standardize the shape and dimension of the ceramic components, a single computeraided design/computer assisted manufacturing (cad/cam) superstructure was designed with dental designer software. based on this model, cad milled zirconia (zr), cad milled lithium disilicate (cadld) and heatpressed lithiumdisilicate (hld) superstructures were fabricated (n=10 per group). they were bonded to the titanium inserts by using selfadhesive resin cement. the prepared superstructuretitanium insert complexes (hybrid abutments) were screwed into the implants with 35 ncm torque. the tensile bond strength of the ceramic superstructures to the titanium inserts were recorded by the universal testing machine with a crosshead speed of 2 mm/min. the data were analyzed by using oneway anova and tamhane posthoc test (p < 0.05).results: the mean±sd of tensile bond strength was 328.50±30.4 n in cadld, 257.30±23.8 n in hld, and 242.20±21.2 n in zr groups. oneway anova revealed the groups significantly different in terms of the tensile bond strength (p < 0.001). tamhane posthoc test showed a significant difference between the cadld and the two other groups (p <0.001); however, no statistically significant difference was detected between the hld and zr groups (p= 0.39).conclusion: it can be concluded that the cadld has higher bond strength to titanium insert compared with the hld and zr groups. therefore, they might be clinically more beneficial in highesthetic areas.