Influence of Cortical Anchorage on Implant Mobility

Influence of Cortical Anchorage on Implant Mobility
27 June 2003
T. SUMIKAWA1, K. SARATANI2, T. KAWAZOE2, H. OKA3, and S.G. SHI4, 1 Graduate School, Osaka Dental University, Japan, 2 Osaka Dental University, Japan, 3 Okayama University Medical School, Japan, 4 306 Hospital of PLA, Beijing, China
IADR
Objectives: Several authors have suggested that cortical anchorage is important to implant stability by studies of stress distribution. However, there were few studies which investigated influence of cortical anchorage on implant stability from a standpoint of implant mobility. We have already developed an Implant Movement (IM) checker which can measure dental implant mobility. The aim of this study was to investigate influence of cortical anchorage on implant mobility. Methods: As imitative implants, bronze cylinders were used. Each diameter of cylinders was 4 mm. The bronze cylinders were embedded vertically in the bases of resin (7x7x4 cm). The bases of resin had two layers (Araldite, Ciba-Geigy, Japan and Rigolac, SHOWA HIGHPOLYMER, Japan) on the assumption of cortical bone and cancellous bone. The layer of cortical bone was 2 mm. Embedded lengths were six kinds (7, 9, 11, 13, 15 and 17 mm). Three models were made per each condition. IM (Implant movement) score was measured using IM checker horizontally. Parametric comparisons of IM score in six embedded lengths used One-factor analysis of variance. We also made implant models without the layer of cortical bone and experimented in a similar way. Results: Significances of individual differences were evaluated by using the Tukey-Kramer test because ANOVA was significant (p<0.01). As a result, significant differences in IM score were observed among 7, 9 and 11 mm (p<0.01). However, there were not significant differences among 11, 13, 15 and 17 mm. And then, IM score of each model with cortical bone was significantly smaller than that without cortical bone (p<0.01). Conclusions: It was suggested that cortical bone contributed to implant stability from the point of view of implant mobility.