Ten-year survival and chipping rates and clinical quality grading of zirconia-based fixed dental prostheses.

OBJECTIVES: To prospectively evaluate the clinical long-term outcome of 3- to 6-unit fixed dental prostheses (FDPs) made of hot isostatic pressed (HIP) zirconia frameworks, veneered with a synthetic sintering glass-ceramic. MATERIALS AND METHODS: A total of 27 different restorations were cemented in 21 patients. FDPs were examined with regard to biological and technical complications/failures. Additionally, clinical quality was assessed based on (i) the California Dental Association (CDA) criteria, (ii) the patient's viewpoint according to Hickel, and (iii) periodontal parameters. Descriptive statistics were computed. The Kaplan-Meier estimator was used for the survival and chipping-free rates. Wilcoxon signed ranks test (ordinal/continuous data) or the McNemar test (binary data) was used to describe the periodontal outcome of abutment teeth versus that of the respective control teeth. RESULTS: After a mean observation period of 10.0 ± 2.1 years, the dataset comprised 15 patients with 20 (mainly posterior) FDPs. The 10-year survival rate and 10-year chipping-free rate were 95.0% (CI 86.0-100%) and 78.8% (CI 62.2-99.7%), respectively. Evaluation based on the CDA criteria yielded satisfactory (excellent or acceptable) results for all categories. This was also confirmed by the high level of patient satisfaction. The periodontal health of tissues adjacent to the study teeth was clinically acceptable, but inferior to the ones of control teeth. CONCLUSIONS: FDPs made from CAD/CAM-fabricated HIP zirconia ceramic frameworks have a favorable survival rate. However, because damage to the surface texture showed a disproportionate increase after long-term usage, additional long-term studies are required. CLINICAL RELEVANCE: The outstanding mechanical properties of zirconia-based systems have contributed to the belief that all-ceramics are a reliable material for prosthetic restorations. However, only long-term reports (such as this one) provide more detailed information on actual clinical efficacy.

Use of molecular indicators of inflammation to assess the biocompatibility of all-ceramic restorations.

AIM: The purpose of this in vivo study was quantification of inflammatory reaction to ceramic restorations made from lithium disilicate and zirconia by measurement of the concentration of indicators of inflammation in the gingival crevicular fluid (GCF). MATERIAL AND METHODS: Patients out of three prospective cohort-studies investigating three different all-ceramic restoration materials for crowns and fixed dental prostheses were included. Patients needed an associated, unrestored tooth to serve as control. GCF samples were taken from the sulcus of the restored teeth and the related controls (n = 59 pairs) and the concentrations of IL1-beta, IL-1ra and aMMP-8, as indicators of inflammation, were determined by use of ELISA tests. Periodontal status was also assessed clinically by measurement of pocket depth (PD), plaque index (PI) and bleeding on probing (BOP). RESULTS: The concentrations of the inflammation indicators were not significantly different between restored teeth and controls or between lithium disilicate and zirconia restorations (p > 0.05). Furthermore, no significant difference between PD of restored teeth and controls or between groups could be shown. CONCLUSION: Within the limitation of the study, treatment with all-ceramic restorations did not induce inflammatory reactions in a group of periodontal healthy patients. No differences between the gingiva reactions of lithium disilicate and zirconia restorations could be shown.