2003 Volume 16 Issue 1 Pages 70-76
The long-standing controversy on which implant: machined screw-type implant, or hydroxyapatite (HA)-coated implant, is superior to the other, has not yet been settled. This paper compares, retrospectively, the survival rates of a hydroxyapatite-coated cylindrical implant system, and a machined screw-type implant system, for non-complicated patients.
The subjects were 34 males and 40 females, of ages from 18 to 75 years, with an average age of 50.5 years. They had no systemic diseases affecting implant treatment. They had enough bone volume for implant placement. The implants used were an HA-coated cylindrical implant:Calcitek implant®(Sultzer Calcitek, USA), of either 3.25 mm or 4.0 mm in diameter, and of 8, 10, 13, or 15 mm in length, and a machined screw-type implant:Brånemark implant®(Nobel Biocare, Sweden), of 3.75 mm or 4.00 mm in diameter, and of 10, 13, or 15 mm in length. The survival rates were assessed using the Kaplan-Meier test. The factors investigated were implant position, anterior/posterior and mandible/maxilla, and implant length.
The following results were obtained:
1. The total survival rates were 97.9% for Brånemark implants up to 5 years, and 94.4% for Calcitek implants up to 7 years.
2. No statistical difference existed between these results.
3. On the length and sites of the implants, the survival rates were more than 90%, except for Calcitek implants 8 mm or 10 mm in length.
4. Overheating during placement and/or post operative infection could be causes of implant failure.
Very high survival rates could be anticipated by both implant systems in patients with enough bone volume in the implanted sites, and without basic diseases affecting the treatment. They could be further elevated by avoiding negative factors.
