Stability of Bone Bed Crest of Loaded Implant – Comparison with Finite Element Models

Overview

The adaptation of the implant bone bed to chewing force has been quite often represented in X-ray images as the bowl shaped resorption around the implant neck. During the first year after the implant loading the marginal bone loss around the neck is more pronounced. Subsequeutly, the rate of the bone loss is either arrested or the resorption of the bone crest continues and the implant is lost within a few years. This study compared stability of the bone bed crest of the loaded implant to the size, shape and inclination of enosseal part of the implant and to the anchored denture. All the implants monitored in the study were scanned by X-ray images every 6 months. The bone profile and stability characteristics for each implant were assembled. Numbers of stable and non-stable implants with respect to their size, shape and inclination of the enosseal part of the implant and to anchored denture were statistically evaluated and compared to mathematical finite element models. Differences among various types of loading, represented by different types of dentures were not significant, excluding a group of fixed bridges, where an implant was used as interpositioned pillar between natural teeth. Correlation between findings in vivo and mathematical models is not distinct. This is probably because movements of mandible and chewing forces are individual and they have not been studied thoroughly yet. Moreover, in models ordinary values were used, whereas in clinical practice it is necessary to use individual values.

Key words:
dental implants – size, shape and inclincation of enosseal part – radiovisiography – dentures – stress distribution – finite element method