The effect of luting media on the fracture resistance of a flame sprayed all-ceramic crown

Objectives: This in vitro study investigated the effect of selected luting media on the fracture resistance of a flame-sprayed all-ceramic crown. Methods: Three groups of 10 human upper premolar teeth were prepared for cr owning using a standardised technique. Flame sprayed crowns were fabricated and cemented onto the preparations using zinc phosphate (ZPC), glass polya lkenoate (GPC) or composite luting cement (CLC). During crown seating, a pr essure perfusion system simulated pulpal fluid outflow equivalent to 300 mm . of H2O. Compressive fracture resistance was determined for each group usi ng a Universal Testing Machine with a crosshead speed of 1 mna min A group of unrestored teeth acted as a control. Results: The fracture resistance of the groups ranked as follows: ZPC > CLC much greater than GPC = unrestored teeth. The difference between the fract ure resistance of ZPC and CLC groups and the control group was statisticall y significant. The mode of fracture between the luted crowns and natural cr owns was markedly different. Conclusions: When tested in compression, a new, flame-sprayed all-ceramic c rown, when luted in place using ZPC, GPC or CLC, could produce strengths co mparable to or greater than natural unrestored teeth. The luting agent used significantly affected the recorded fracture loads. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.