残存歯の歯槽骨喪失率とハイドロキシアパタイト・コーティング・インプラントの長期臨床経過の関係

抄録

This study analyzed the clinical prognosis of HA-coating implants in the mandibular posterior region in patients with varying experience of periodontal bone loss in the natural dentition before implant placement. By assessing the degree of radiographic marginal bone loss in the remaining natural dentition at the time of the implant therapy, an age-related bone loss score (ArB-score) was calculated to describe the patient's experience of periodontal destruction. The two end quartiles of the description of the patients with regard to the ArB-score were defined as High ArB-score group and Low ArB-score group, respectively.
For the prognosis observation after implant placement, a parameter of implant was bone resorption of implant body circumference and drop-out of implant. As a result, a total of 223 HA-coating implants were inserted in the 68 patients. In the Low ArB-score group, 6 implants failed from the time of bridge installation to 5-11 years as compared to 15 in the High ArB-score group. Hence, the 5-11 success rate was 94.9% in the Low ArB-score and 85.7% in the High ArB-score group. The High ArB-score group had a significantly higher incidence of implant failure than the Low ArB-score group.
These results showed that the patients who were characterized as Low ArB-score had a good prognosis even if HA-implant was selected. However, in the case of HA-implant placement in a patient characterized as High ArB-score, the possibility of resorption of implant body circumference bone and drop-out of implant during the maintenance period was high.