Effect of Cement Chemistry and Ti-Base Abutment Design on Bond Strength and Interfacial Failure Behaviour of Implant-Supported Zirconia Crowns: An In Vitro Comparative Study

Sammanfattning

Crown debonding is one the most frequently reported complications in cement-retained,implant-supported zirconia restorations. But still, it is not fully understandable how cement chemistry and abutment design work together to affect bond durability. Titanium-base (Ti-base) abutments are now widely used to connect zirconia crowns to implants, but there is still limited evidence on which cement-abutment pairing holds best. The study tested zirconia crowns cemented ontro two Ti-Base systems, DUS and DESS, using three different cements: Panavia V5 (an MDP-based dual core resin), G-CEM(a resin modified glass ionomer) and ZirCAD (a self-adhesive resin). Thirty specimens were pulled part aparta on a Shimadzu Universal Testing machine. Afterward,the broken interfaces were examined under a microscope to classify each failure as adhesive, cohesive or mixed. Cement type drove the results, not abutment design. It accounted for the majority of tha variance in bond strength, over 60% (F(2,23) =20.39, p<0.001). Abutment type made almost no difference (p=0.664). ZirCAD consistently gave the weakest bonds. G-CEM gave the strongest readings, but the strength was misleading. It failed almost entirely adhesively, especially on DESS, meaning the high numbers came from the cements's bulk strength rather than real adhesion to the abutment. Panavia V5 told a different story. On DUS abutment it failed cohesively , or mixed more just as expected from genuine MDP-TiOx bonding. On the other hand, in case of DESS Abutment it shifted forward to adhesive failure. Hinting that the oxide layer differs enough between abutment brands to affect how well MDP bonds. ZirCAD failed cohesively on bond abutment systems but simply was not strong enough. Overall, DUS paired with Panavia V5 came out as the more dependable combination.