抄録
To evaluate the risk factors of the loss of osseointegration (late failure) of titanium implants,we statistically carried out a clinical examination 392 fixtures of Brånemark implant, for which a one-year follow-up after the fitting of superstructures had been completed. Seven fixtures (1.8%) lost their osseointegration within one year after the fitting of superstructures.
The results are summarized as follows:
1. Age and sex did not affect late failure.
2. There was no significant difference in the rate of late failure between the maxilla and the mandible. In the mandible, the prognosis of fixtures installed in the posterior region to the mental foramen was worse than that of fixtures installed in the anterior region.
3. The kinds of fixtures did not affect late failure.
4. The prognosis of fixtures of 5 mm or more in diameter was poor.
5. The prognosis of fixtures of 10 mm or less in length was poor.
6. The initial stability of fixtures at the installation and the healing period between fixture installation and abutment connection did not affect late failure.
7. With regard to the number of fixtures connected in a superstructure, the fixtures connected with 6 or more frequently failed.
8. Smoking and state of opposing dentition did not affect late failure.
These results demonstrated that short fixtures,wide fixtures and large number of fixtures connected in a superstructure are risk factors in the loss of osseointegration (late failure).
