Zirconia implants restored with single crowns or fixed dental prostheses: 5-year results of a prospective cohort investigation.
AIM
To evaluate the clinical and radiological outcomes of one-piece zirconia implants restored with single crowns (SCs) or fixed dental prostheses (FDPs) over an observation period of 5 years in function.


MATERIALS AND METHODS
In a prospective cohort investigation with two investigational centers, one-piece zirconia implants were placed in anterior and posterior sites. After a healing period of at least 2 months in the mandible and 4 months in the maxilla with immediate provisional reconstructions, the final all-ceramic SCs or three-unit FDPs were cemented. Patients were followed for 5 years. Clinical parameters and radiological measurements of the implants and the neighboring teeth were assessed. For the statistical analysis, linear mixed models were applied.


RESULTS
A total of 71 implants were placed in 60 patients. Sixty-three implants in 53 patients could be evaluated at the 5-year follow-up. Six patients with a total of seven implants were counted as dropouts. One implant did not achieve adequate osseointegration and had to be removed 5 weeks after implantation. The 5-year survival rate was calculated as 98.4% (95% CI 91.6, 99.9). The mean overall marginal bone loss from implant placement to the 5-year follow-up was 0.7 ± 0.6 mm. After an initial mean marginal loss before loading the implants (0.7 mm), no further statistically significant change in marginal bone level (p = .458) could be observed.


CONCLUSION
The investigated one-piece zirconia implant showed a high survival rate, very stable marginal bone, and mucosal margin levels after 5 years in function. Therefore, it can be considered safe and reliable for the reconstruction of implant-supported SCs or FDPs over a mid-term period.
['Balmer|Marc|M|https://orcid.org/0000-0003-0637-8314', 'Spies|Benedikt C|BC|https://orcid.org/0000-0003-1702-1679', 'Kohal|Ralf-Joachim|RJ|https://orcid.org/0000-0001-7095-4190', 'Hämmerle|Christoph Hans-Franz|CH|https://orcid.org/0000-0002-8280-7347', 'Vach|Kirstin|K|', 'Jung|Ronald E|RE|https://orcid.org/0000-0003-2055-1320']
D003442:Crowns D015921:Dental Implants D017267:Dental Prosthesis Design D019094:Dental Prosthesis, Implant-Supported D019232:Dental Restoration Failure D003830:Denture, Partial, Fixed D006801:Humans D011446:Prospective Studies D015040:Zirconium
zirconia clinical osseointegration bone ceramic dental implants human