Analysis of strain around endosseous dental implants opposing natural teeth or implants

Statement of problem

Natural teeth and implants have different force transmission characteristics to bone.

Purpose

The purpose of this study was to compare strains induced around a natural tooth opposing an implant with strains around occluding implants under static and dynamic loads.

Material and methods

Occlusion was created between a natural molar tooth and an implant in 1 side, and 2 implants in the contralateral side of acrylic resin models of both jaws. Strain-gauges were bonded around the neck of the natural tooth and implants, and strains were measured under 75 N and 100 N static axial and lateral dynamic loads in separate load situations using a data acquisition system at sample rate of 1000 Hz. The strain data of the natural tooth and implants were compared for each load by Kruskal-Wallis testing followed by the multiple comparison test (α=.05).

Results

Compressive strains were induced around natural tooth and implants as a result of static axial loading, whereas combinations of compressive and tensile strains were observed during lateral dynamic loading. Strains around the natural tooth were significantly lower than the opposing implant and occluding implants in the contralateral side for most regions under all loading conditions (P<.05). There was a general tendency for increased strains around the implant opposing natural tooth under higher loads and particularly under lateral dynamic loading (P<.05).

Conclusion

Under static and dynamic loads, strain magnitudes around a natural tooth were significantly lower than that of an opposing implant and occluding implants in the contralateral side.