Abstract
The aim of this project was to evaluate single synthetic sapphire
crystals as dental implants, with special reference to correlation of
clinical and in vitro/in vivo methods of research. The laboratory studies
confirmed chemical stability. The nontoxic properties were confirmed by
in vitro tests showing no disruption to normal cell function in cell
cultures of human oral epithelial cells and fibroblasts. Tissue-implant
interactions were studied in animal experiments: thirty Sprague-Dawley
rats were used for subcutaneous implantation and two inbred beagle dogs
for mandibular bone implantation. The subcutaneously implantated sapphire
rods showed a minimal foreign body reaction after 4-12 weeks in situ. In
the intraosseous implantation experiment the implants and surrounding
tissues were removed after 6 months in situ: for histological and
histometric analysis. Showed that bone contact to the implants was appr.
62% and the peri-implant mucosa closely resembled the mucosa surrounding
the tooth.
In the clinical studies, conducted in one Swedish and one Norwegian
specialist clinic, 86 patients with edentulous mandibular were treated
with overdentures supported by sapphire implants. To determine implant
success, clinical evaluation and radiographic features were monitored. Of
the initial 324 implants, 28 implants were lost during the first 42
months. For the remaining implants, the cumulative implant success rates,
based on radiographic and clinical criteria varied from 95.2% at the end
of the prosthetic treatment to 91.3% at the twelve year follow-up. The
radiographic analysis of the remaining implants showed no statistically
significant changes in the bone implant score index (BIS), measured from
baseline to the five year follow-up. Correlation of the experimental and
clinical data indicate that the single synthetic sapphire crystal dental
implant system is an appropriate method for rehabilitation of mandibular
edentulism.
