Monolithic zirconia reconstructions supported by teeth and implants: 1- to 3-year results of a case series.

OBJECTIVE: Today, only scarce information is available on monolithic zirconia reconstructions. The objective of this study was to evaluate the performance of monolithic zirconia for tooth- and implant-borne reconstructions. METHOD AND MATERIALS: Monolithic zirconia single crowns (SCs) and fixed dental prostheses (FDPs) supported by implants or teeth were included in this study. Implant placement and prosthetic treatment were done in the same clinical setting. One technician performed all laboratory work using the same CAD/CAM workflow (DentalDesigner, Ceramill Motion 2, Amann Girrbach). The endpoints were technical outcome, color match, marginal adaptation, anatomical form, and biologic aspects. The modified United States Public Health Service (USPHS) criteria and periodontal parameters were applied for the clinical evaluation by two independent examiners. Descriptive statistics and nonparametric tests were used for statistical comparisons. RESULTS: Forty patients (17 men, 23 women, mean age 59.1 ±â€¯14.7 years) with 109 reconstructions (74 SCs, 35 FDPs) supported by 38 implants and 71 teeth were assessed, resulting in a total of 238 monolithic zirconia units (including 62 pontics and 18 cantilevers). Median follow-up time was 23.8 months (12 to 36 months). No technical failures were observed. The total prosthesis survival rate was 99.6% (teeth, 100%; implants, 98.4%) due to the loss of one implant. The periodontal/peri-implant parameters stand for healthy tissue, and caries was not detected. The records obtained by the USPHS revealed good clinical outcomes. CONCLUSION: These short-term results indicate that monolithic zirconia reconstructions for teeth and implants may be a satisfactory treatment option, particularly in the posterior region.

Zirconia-Based Screw-Retained Prostheses Supported by Implants: A Retrospective Study on Technical Complications and Failures.

BACKGROUND: Little information is yet available on zirconia-based prostheses supported by implants. PURPOSE: To evaluate technical problems and failures of implant-supported zirconia-based prostheses with exclusive screw-retention. MATERIAL AND METHODS: Consecutive patients received screw-retained zirconia-based prostheses supported by implants and were followed over a time period of 5 years. The implant placement and prosthetic rehabilitation were performed in one clinical setting, and all patients participated in the maintenance program. The treatment comprised single crowns (SCs) and fixed dental prostheses (FDPs) of three to 12 units. Screw-retention of the CAD/CAM-fabricated SCs and FDPs was performed with direct connection at the implant level. The primary outcome was the complete failure of zirconia-based prostheses; outcome measures were fracture of the framework or extensive chipping resulting in the need for refabrication. A life table analysis was performed, the cumulative survival rate (CSR) calculated, and a Kaplan-Meier curve drawn. RESULTS: Two hundred and ninety-four implants supported 156 zirconia-based prostheses in 95 patients (52 men, 43 women, average age 59.1 ± 11.7 years). Sixty-five SCs and 91 FDPs were identified, comprising a total of 441 units. Fractures of the zirconia framework and extensive chipping resulted in refabrication of nine prostheses. Nearly all the prostheses (94.2%) remained in situ during the observation period. The 5-year CSR was 90.5%, and 41 prostheses (14 SCs, 27 FDPs) comprising 113 units survived for an observation time of more than 5 years. Six SCs exhibited screw loosening, and polishing of minor chipping was required for five prostheses. CONCLUSIONS: This study shows that zirconia-based implant-supported fixed prostheses exhibit satisfactory treatment outcomes and that screw-retention directly at the implant level is feasible.

Technical complications and failures of zirconia-based prostheses supported by implants followed up to 7 years: a case series.

PURPOSE: To evaluate technical complications and failures of zirconia-based fixed prostheses supported by implants. MATERIALS AND METHODS: Consecutive patients received zirconia-based single crowns (SCs) and fixed dental prostheses (FDPs) on implants in a private clinical setting between 2005 and 2010. One dentist performed all surgical and prosthetic procedures, and one master technician performed and coordinated all laboratory procedures. One-piece computer-aided design/ computer-assisted manufacture technology was used to fabricate abutments and frameworks, which were directly connected at the implant level, where possible. All patients were involved in a recall maintenance program and were finally reviewed in 2012. Data on framework fractures, chipping of veneering ceramics, and other technical complications were recorded. The primary endpoint was failure of the prostheses, ie, the need for a complete remake. A life table analysis was calculated. RESULTS: A total of 289 implants supported 193 zirconia-based prostheses (120 SCs and 73 FDPs) in 127 patients (51 men, 76 women; average age: 62.5 ± 13.4 years) who were reviewed in 2012. Twenty-five (13%) prostheses were cemented on 44 zirconia abutments and 168 (87%) prostheses were screw-retained directly at the implant level. Fracture of 3 frameworks (1 SC, 2 FDPs) was recorded, and significant chipping resulted in the remake of 3 prostheses (1 SC, 2 FDPs). The 7-year cumulative survival rate was 96.4% ± 1.99%. Minor complications comprised 5 loose screws (these were retightened), small chips associated with 3 prostheses (these were polished), and dislodgement of 3 prostheses (these were recemented). Overall, 176 prostheses remained free of technical problems. CONCLUSIONS: Zirconia-based prostheses screwed directly to implants are clinically successful in the short and medium term.