Three-dimensional photoelastic analysis of edentulous alveolar bone supported with magnet retained mandibular implant-supported overdentures

Objective:To study stress distribution of edentulous alveolar bone supported with magnet retained mandibular implant-supported overdentures.Method:Photoelastic models of epoxy were fabricated according to the standard mandibular edentulous model with two implants in the canine areas.The bio-functional complete dentures was made and connected with magnet attachments.Force was applied in conditions of centric,lateral and protrusive occlusion.After stress frozen,photoelastic model slices of different areas were made and stress fringes were observed.Result:In conditions of centric,lateral and protrusive occlusion,the maximum stress was observed on the alveolar bone around implants,more stress was observed on the molar areas,less tress was observed on the incisive areas.In centric or protrusive occlusion,stress was focused on the buccal alveolar bone of molar areas and the lingual alveolar bone of incisive areas.In lateral occlusion,stress was focused on the buccal alveolar ridge of work side and the lingual alveolar ridge of balance side.Conclusion:Stress of magnet retained mandibular implant-supported overdentures was distributed not only on the alveolar bone around the implants but also on the residual alveolar ridges,which can decrease the stress of alveolar bone around implant and increase the health of implant.