The International Journal of Oral & Maxillofacial Implants, 02/1987

An in vitro study of the influence of calcium phosphate hydroxylapatite on dose distribution in electron beam (15 MeV) radiation therapy was performed. Results indicate that no precautionary measures need to be taken. However, the need for further in vivo studies to determine the effects of such therapy on the biologic properties of material seems evident.

Implants of commercially pure titanium were inserted in the rabbit tibial metaphysis. After a healing time of 3 weeks, 1, 3, 6, and 12 mo the average torque levels necessary for implant removal were 10, 16.8, 68, 77.6, and 88 Ncm, respectively. In a morphological part of the study it is demonstrated that there is a gradual increase of bone in direct contact with the implant surface with increasing time of follow-up.

An account is given of the practical problems and complications encountered by and referred to the authors during the first 4 years of clinical use of the Brånemark system at the University of Washington. Most of the problems were iatrogenic and avoidable by careful planning, adherence to the recommended protocol, and the exercise of good judgment. No significant faults were found to be inherent in the system itself.

When replacement of a missing tooth or teeth is being planned, excessive resorption of alveolar bone may complicate the clinical problem. A simple, esthetic, fixed restoration can often be more easily made after local augmentation of the defect with hydroxylapatite via a palatally extended flap.

The impressive Swedish reports suggesting predictable and frequent longitudinal success with osseointegration in edentulous patients demanded a replication study to underscore the merit of universal application. This is a report from the Toronto prospective study where traditional clinical criteria were used to assess the long-term efficacy of the Brånemark technique. While the duration of the study is relatively short (maximum 3 years) it appears to support the Swedish researchers' results. Furthermore, alternate prosthetic methodologies are described, and the argument is advanced that the surrogate gingival and periodontal indices used may not be suitable for assessing the clinical evidence of osseointegration.

Maximum occlusal force differences between conventional complete dentures and fixed mandibular implant dentures opposing a complete maxillary denture are being monitored in patients being treated. This preliminary report of results from 14 patients reveals a statistically significant improvement for both maximum and mean differences. Additionally, patients in this report who were edentulous =15 years had an increase of four times those who were edentulous > 15 years.

An acquired maxillary defect is obturated with a magnetically assisted prosthesis. Hydroxylapatite-coated implants support the frame containing the magnet keepers.