Norio Kaneko

Breaking Strength of Dental Implant using Bioactive Glass. Stress Analysis by 3D Finite Element Method.

The purpose of this study was to clarify the mechanical characteristics of dental implants using Bioactive Glass.The value of the load bearing strength determined by the breaking strength test was used as a base to observe and analyze the implant through the 3-D Finite Element Method. These results were then compared to the analytical results from an implant model and evaluated.Results showed that fracturing of dental implants or implants coming loose was solely dependent upon where the load was applied, load angle, and direction of load application.Placement of the dental implant is determined by taking into consideration the direction of the occlusal force.The direction of load bearing in relation to occlusal contact on the outer oblique plane of the cusp and midportion of the occlusal plane was found to be desirable between 90°to 135° and 60°Cto 120°C, respectively.

Dental Implants using Bioactive Glass-Stress Analysis by the Finite Element Method. Part 2. Stress Analysis of the Superstructure.

Stress distribution depending on the material and shape of the superstructure of bioactive glass implants were analyzed by the finite element method to observe its function and stability. Focus was placed upon the effect of applying various degrees of force to different types of materials used in the coronal and body portion of the superstructure, as well as changing the width of the superstructure and observing its stress distribution.Results were as follows:1. Stress value was higher in the metal core portion of the superstructure when compared to the gold alloy.2. Stress value was highest among the gold alloy crowns.3. Stress build-up was irrelevant to coronal width when force was applied at the center of the occlusal plane.4. As force was applied continuously from the implant axis, stress build-up was observed in the shoulder or base portion of the superstructure.5. Stress build-up was affected more by force placement and direction, rather than force strength.In conclusion, applied force in the center of the occlusal plane should be at a 75°-105° angle. However if force is to be applied on the outer oblique planes of the buccal cusp, the force should be at a 105°-120° angle.