Microleakeage and resin cement film thickness of luted all-ceramic and gold electroformed porcelain-fused-to-metal crowns.

摘要

PURPOSE: The purpose of this study was to evaluate the sealing ability of single-unit all-ceramic and gold-electroformed crowns luted with a resin cement under laboratory conditions. MATERIALS AND METHODS: Thirty extracted maxillary premolars were selected. Standardized abutments were prepared for full-crown restorations with cervical margins located 1 mm below the cementoenamel junction. Samples were divided into two groups (n = 15) based on type of restorative system: Group 1: a heat-pressed all-ceramic system (IPS Empress 2, Ivoclar-Vivadent); Group 2: a gold-electroformed porcelain-fused-to-metal system (Gramm Technik). Crowns were luted with Excite DSC bonding system (Ivoclar-Vivadent) and Variolink II resin cement (Ivoclar-Vivadent) following manufacturer's instructions. After luting procedures and 700 thermal cycles (5 degrees C and 55 degrees C, 1 min dwell time), 20 specimens (n = 10 per group) were randomly selected and processed for microleakage evaluation at cervical sites. The remaining specimens (n = 5 per group) were prepared for SEM investigation on film thickness. Microleakage and film thickness data were statistically evaluated using the Mann-Whitney U-test (p < 0.05). RESULTS: Fifty percent of group 1 and 60% of group 2 samples showed leakage. For group 1, dye penetration was mostly observed between metal and resin material, while group 2 specimens showed leakage mainly between ceramic margins and resin cement. Samples from group 1 showed a cement thickness of 82 microm, while 71 microm was found for group 2. Statistically significant differences were not found between samples from the two groups. CONCLUSION: Regarding microleakage and film thickness, both restorative systems evaluated in this study performed similarly.