Finite Element Analysis of Stress Distributions for Mandibular Dental Implant-Supported Overdentures with Magnetic Attachments in Osteoporotic and Normal Bone.

PURPOSE: To compare the biomechanical responses of a normal mandible to an osteoporotic mandible with two-implant-supported magnetic attachments.

MATERIALS AND

METHODS

A 3D finite-element model of a two-implant-supported mandibular overdenture with magnetic attachments was developed, and normal and osteoporotic bone samples were prepared. Four types of load were applied to the overdenture in each model: 100 N vertical and oblique loads on the right first molar, and a 100 N vertical load on the right canine and incisors. Biomechanical behaviors of the peri-implant bone, implant, and mucosa were recorded. Maximum equivalent stresses and elastic strains were analyzed.

RESULTS

Equivalent elastic strain in osteoporotic cortical and cancellous bone was 9% to 71% and was 142% and 207% greater than in normal cortical bone, respectively. Equivalent elastic strain in the first molar oblique loading condition was 101% to 190% greater than in the first molar vertical loading condition.

CONCLUSIONS

Osteoporotic cancellous bone was weaker and less resistant to deformation than normal bone, and oblique loading was more harmful than vertical loading.