CLINICS 2011;66(12):2063-2070 CLINICAL SCIENCE DOI:10.1590/S1807-59322011001200011 A 3-year follow-up study of all-ceramic single and multiple crowns performed in a private practice: a prospective case series Gianluca M. Tartaglia,I,II Ernesto Sidoti,II Chiarella SforzaI I Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell’Apparato Stomatognatico, Dipartimento di Morfologia Umana e Scienze Biomediche – Citta` Studi, Facolta` di Medicina e Chirurgia, Universita` degli Studi di Milano, Milano, Italy. II SST Studio Associato Sidoti & Tartaglia, Segrate (MI), Italy. OBJECTIVES: Zirconia-based prostheses are commonly used for aesthetic crown and fixed restorations, although follow-up data are limited, especially for implant-supported crowns. The aim of this study was to evaluate the three- year clinical results of the installation of 463 zirconia core crowns by a general dental private practice. METHODS: This study followed 142 patients (69 men and 73 women; aged 28-82 years) who had received 248 single crowns (202 tooth-supported, 36 implant-supported) and 225 multiple units of up to six elements (81 tooth- supported, 144 implant-supported). Clinical events, including fracture and loss of retention, secondary caries, and marginal integrity, were recorded. The overall failure rate was computed for the fractured and lost prostheses. Aesthetic, functional, and biological properties were rated, and patient satisfaction was investigated. RESULTS: During the three-year follow-up period, four patients were lost from the study (18 crowns, 4% of the total crowns). Three of the zirconia prostheses suffered fractures in more than three units (11 crowns; one- vs. three-year follow-up, p,0.05, Wilcoxon signed-rank test), and the cumulative prosthesis survival rate was 98.2%. Twelve units lost retention and were re-cemented, and no secondary caries of the abutment teeth were reported. The aesthetic, functional, and biological properties were generally well-rated, and there were no differences between tooth- and implant-supported crowns. The lowest scores were given regarding the anatomical form of the crowns, as some minor chipping was reported. Relatively low scores were also given for the periodontal response and the adjacent mucosa. Overall, patient satisfaction was high. CONCLUSIONS: At the three-year follow-up, the zirconia-core crowns appeared to be an effective clinical solution as they had favorable aesthetic and functional properties. Only the marginal fit of the prostheses should be improved upon. KEYWORDS: Zirconia; Prostheses; Implants; All-ceramic crowns; Clinical performance. Tartaglia GM, Sidoti E, Sforza C. A 3-year follow-up study of all-ceramic single and multiple crowns performed in a private practice: a prospective case series. Clinics. 2011;66(12):2063-2070. Received for publication on June 2, 2011; First review completed on August 8, 2011; Accepted for publication on August 29, 2011 E-mail: chiarella.sforza@unimi.it Tel.: +39 02 503 15407 INTRODUCTION Porcelain-fused-to-metal (PFM) restorations have been the prevailing technology for aesthetic crown and fixed- prosthesis restorations for approximately 50 years.1 However, the failure of these restorations is often related to technical or clinical problems, such as ceramic breakage fractures from the metal substructure, or aesthetic complica- tions, such as the unnatural appearance of the prosthesis. Copyright 2011 CLINICS – This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. No potential conflict of interest was reported. To overcome these problems, dental ceramics have been used as alternatives to metallic dental restoration. Feld- spathic ceramics have met patient aesthetic demands but do not provide adequate structural integrity, especially for the posterior teeth. With the development of crystalline cera- mics, alumina and zirconia came into use for prosthetic reconstructions; these were first used for orthopedics and later for dentistry.2-5 Overall, from a mechanical perspec- tive, prosthetics composed of oxide/crystalline ceramics are superior to those made with feldspathic/glass ceramics,6,7 and these are considered a viable alternative to PFM restorations.2,5,8-12 Zirconia is a crystalline dioxide of zirconium. In parti- cular, yttrium-oxide-partially-stabilized zirconia (3Y-TZP) has mechanical properties very similar to those of metals, yet it has a color similar to that of teeth.3,4,13 Its mechanical properties, which are similar to those of stainless steel, allow 2063