engleski

Is the density of the bone surrounding fixed partial denture (FDP) abutments increased in comparison to homologous teeth?

Purpose: It is assumed that abutments of the FPD bear more load than homologous teeth as they also take loads from the missing units. The aim of this study was to evaluate bone density of FPD restorations being successfully in function several years and to compare it with homologous teeth. The hypothesis was that the abutments might present higher density than homologous teeth. Material and Methods: The bone density (expressed in equivalents of Cu stepwedge thickness, attached to the digital x-ray sensor), was measured at the mesial and distal side of the root of both, abutments and homologous teeth at the alveolar crest level, the middle of the root, the root apex, as well as bellow the apex. A total of 70 patients with 146 abutments participated. Mean age of satisfactory FPDs was 4.9 years. Results: The bone density increased from the alveolar crest towards the apex in both, the FPD abutments and the homologous teeth (p<0.01). The bone density was significantly higher distally than mesially at the alveolar crest level in both, FDP abutments and homologous teeth (p<0.01). Men had significantly denser bone than women only at the level of the middle of the root and at apex (p<0.05). There was no significant difference of bone density between abutments and homologous teeth (p>0.05). There was no significant effect of age, FPD material, type of abutment (single crown or bridge), abutment/pontic ratio (1:0.5 ; 1:1 ; 1:1.5 ; 1:2), and Ante’s law (p>0.05). Conclusions: Lower bone density at the level of alveolar crest mesially than distally in FPD abutments and homologous teeth should not be considered a pathological finding. It is attributed to the increase of bone volume towards distal parts of the alveolar bone. No difference of bone density between abutments and homologous teeth is attributed to the load distribution of the missing units through the interdental contact points over the dental arch. The findings of the present study emphasize the importance of interdental contact points in FPDs.

bone density; fixed partial dentures; abutments

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