Influence of luting agent on the microleakage of all-ceramic crowns

Objectives: This in-vitro study evaluated the microleakage of all-ceramic crowns using 2 different marginal preparation types and 3 different dual-cure resin cements. Porcelain-fused to metal (PFM) crowns were cemented with a zinc phosphate cement for the control.

Methods: Seventy freshly extracted maxillary central incisors were randomly divided into seven groups (n=10). Thirty teeth were prepared with a 90-degree shoulder with rounded internal line angle, while the others were prepared with a chamfer finish line. IPS-Empress 2 crowns (Ivoclar Vivadent; Schaan, Liechtenstein) were manufactured for all teeth excluding the control group. After the cementation procedure samples were stored in distilled water for 30 days. All samples were subjected to 5000 thermocycles (at 5°C to 55°C; 30-second dwell time). After immersion in Indian ink for 48 hours at 37°C, the samples were sectioned both buccolingually and mesiodistally using the EXACT cutting and grinding system. Each section was evaluated under stereomicroscope (Zeiss) at X24 magnification for evaluation of microleakage.

Results: Kruskal-Wallis test revealed no significant difference (p>.05) among the groups that dual-cure resin cements were used for the cementation. Mann-Whitney U-test demonstrated statistically significant difference (p<.05) between group 1, 2, 3, 4 and the control group. Dual-cure resin cements demonstrated the least leakage.

Conclusion: Dual-cure resin cement showed a better ability to minimize leakage of all-ceramic crowns