AN ANALYSIS OF STRESS DISTRIBUTION AROUND THE IMPLANT ACCORDING TO THE BONE QUALITY AND BITE FORCE: FINITE ELEMENT METHOD

Since the early study about the osseointegration, lots of researches have been performed to increase the success rate and the stress around the implant in the jaw bone has been considered as one of the causes of failure. The purpose of this study was to examine the relationship between the implant failure and the stress by analysing the influence of different bone quality and bite force of some foods on the stress distribution around the implant, and to estimate the treatment result according to the bone quality and dietary pattern of patients. Bone quality was divided in 4 groups and models were drawn with the assumption that thread type implant(Nobel Biocare AB, Goteborg, Sweden) of 3.75mm diameter, 13mm length was installed to the bones. Various bite forces were applied to the occlusal surface of superstructure and the stress distributed around the implant were analysed with finite element analysis program. The results were as follows ; 1. The stress was changed proportionally to the bite forces of foods at all measuring points in all load cases. 2. The stress at the marginal bone was higher than that of the other measuring points in all load cases, and it was decreased at the first thread area. 3. The stress at the marginal bone was highest in type IV bone in all load cases. Especially it was twice those of other bone types at the bucco-lingual marginal bone and 50% higher at the mesio-distal marginal bone. 4. The stress at the bucco-lingual sides of the bone around the apical portions of implant showed little differences among the bone types, while type IV bone showed lower stress concentration than the other bone types in the mesio-distal sides. 5. Under the buccal oblique load ( ), the stress at the lingual marginal bone was higher than that of buccal marginal bone, and the difference between the two points was almost same regardless of bone types