Retentive bond strength of different luting cements to zirconium oxide ceramic crowns: an in vitro study

Aim: This study was undertaken to evaluate the bond strength of different luting cements to zirconium oxide ceramic crowns. Materials and Methods: Thirty extracted human premolar teeth were prepared and used in the study for fabrication of zirconium oxide ceramic copings. These copings were then divided into three groups: - Group I (GC Gold Label), Group II (Calibra) and Group III (Panavia F 2.0), which consisted of ten copings each for cementation. The samples were then subjected to a crosshead speed of 0.5mm/min for dislodgement of copings along the apico-occlusal axis until failure on Universal testing machine. The data obtained was subjected to statistical analysis. Statistical Analysis: The statistical tests used were ANOVA test for difference between the mean values and chi-square test for difference between the proportions. The level of significance was taken at 5% (p<0.05). The F-test is used for comparisons of the components of the total deviation Bonferroni test is used for multiple comparisons. Result: The result showed that the mean retentive force for Group I cement was 126.9 ± 31.52, for Group II cement was 256 ± 58.04 and for Group III cement was 271.4 ± 51.15. Group I cement had the least retentive strength for retaining zirconium oxide copings. Conclusion: It was concluded that Groups II and III are capable of retaining zirconium oxide copings successfully with no additional internal surface treatment other than airborne-particle abrasion with 50-µm aluminium oxide.