Mechanics analysis for implant‐soft tissue retained overdenture

Abstract

This paper primarily compares retention among three types of stud attachments of dentures and analyzes the stress associated with polarized photoelasticity to elucidate the stress distribution of various implants near the ambient surface of an implant under different conditions of loading on the prosthetics of a tooth. The experimental results yield many significant data. Using the two‐force principle to measure the retention of attachments yields two important areas of results. Under dry conditions, the O‐ring attachment has the largest retention force. While under wet conditions, the Zest attachment has the largest retention force. The photoelastic method is applied to analyze the stress distribution on the arch mandible. When the implants are loaded, the magnetic attachment will generate the largest stresses on the implant. The stresses associated with the Zest attachment are the smallest and can be neglected. Concerning the materials of the experimental arch model, PL‐2 photoelastic birefringent material is used to make the experimental arch model, which is similar to the true arch mandible. PSM‐1 photoelastic birefringent material is used to make a semicircular model, which is easier to manufacture and is also used to simulate the human mandible. The experimental results indicate that the stresses in the PL‐2 arch model are concentrated on the bottom of the implant, and those in the PSM‐1 are on the circumference of the implant approximately one‐third of the height from the bottom. The stress on the PL‐2 arch model clearly exceeds that on the PSM‐1 arch model. The PL‐2 arch model more closely captures the practical clinical situation because its implant is imbedded in the alveolar bone with no clearance. Therefore, the PL‐2 arch model is strongly recommended for future study.