wileyonlinelibrary.com/journal/clr Clin Oral Impl Res. 2018;29:290–299.
© 2018 John Wiley & Sons A/S.
Published by John Wiley & Sons Ltd
Accepted: 23 November 2017
Three- year analysis of zirconia implants used for single-
tooth replacement and three- unit fixed dental prostheses: A
prospective multicenter study
| Benedikt C. Spies
| Kirstin Vach
| Ralf-Joachim Kohal
Christoph H. F. Hämmerle
| Ronald E. Jung
Clinic of Fixed and Removable
Prosthodontics and Dental Material
Science, Center of Dental Medicine, University
of Zurich, Zurich, Switzerland
Department of Prosthetic Dentistry, Faculty
of Medicine, Center for Dental
Medicine, Medical Center, University of
Freiburg, Freiburg, Germany
Charité – Universitätsmedizin Berlin,
Campus Benjamin Franklin (CBF), CC 3 Dental
and Craniofacial Sciences, Department of
Prosthodontics, Geriatric Dentistry and
Craniomandibular Disorders, Berlin, Germany
Center for Medical Biometry and Medical
Informatics, Institute for Medical Biometry
and Statistics, University Medical Center
Freiburg, Freiburg, Germany
Marc Balmer, Clinic of Fixed and Removable
Prosthodontics and Dental Material Science,
Center of Dental Medicine, University of
Zurich, Zurich, Switzerland.
Aim: The aim of the present investigation was to evaluate clinically and radiographi-
cally the outcome of zirconia oral implants after 3 years in function.
Materials and methods: In 60 patients in need of either a single- tooth replacement or
a three- unit fixed dental prosthesis (FDP), a total of 71 one- piece zirconia implants
were placed and immediately restored with temporary fixed prostheses. After a period
of at least 2 months in the mandible and at least 4 months in the maxilla, zirconia-
based reconstructions were cemented. The implants were clinically and radiologically
examined at implant insertion, prosthetic delivery, at 6 months and then yearly up to
3 years. A linear mixed model was used to analyze statistically the influence of prog-
nostic factors on changes in the marginal bone level.
Results: Seventy- one implants (48 in the mandible, 23 in the maxilla) inserted in 60
patients were restored with 49 crowns and 11 FDP. One patient lost his implant after
5 weeks. Five patients with one implant each could not be evaluated after 3 years.
Based on 55 patients with a total of 66 implants, the mean survival rate was 98.5%
after 3 years in function. A statistically significant mean marginal bone loss
(0.70 mm ± 0.72 mm) has been detected from implant insertion to the 3- year follow-
up. The largest marginal bone loss occurred between implantation and prosthetic de-
livery (0.67 mm ± 0.56 mm). After delivery, no statistically significant bone level
change was observed (0.02 mm ± 0.59 mm). None of the investigated prognostic fac-
tors had a significant influence on changes in the marginal bone level.
Conclusions: After 3 years in function, the investigated one- piece zirconia implant
showed a high survival rate and a low marginal bone loss. The implant system was suc-
cessful for single- tooth replacement and three- unit FDPs. Further investigations with
long- term data are needed to confirm these findings.
bone, ceramic, clinical, dental implants, human, osseointegration, zirconia
1 | INTRODUCTION
Endosseous screw- type implants offer a good opportunity to re-
store missing or lost teeth. Nowadays, there are a variety of different
implant systems and implants made of different materials available on
the dental market. Regarding the material, implants from commercially
pure titanium present the largest group of the used implants in the
last decades. Based on various systematic reviews, titanium implants