J Korean Acad Prosthodont.  1997 Sep;35(3):609.

A THREE DEMENTIOAL FINITE ELEMENT ANALYSIS OF THE EFFECT OF SEVEN IMPLANT DESIGNS ON STRESS DISTRIBUTION

• Heo SJ
• Han CH
• Chung JP

Abstract

INTRODUCTION Stress or strain-induced bone remodeling is an important response in unctional adaptation of bone around implants. The overload on the implants can cause the pathologic bone resorption and results in the implant failure. The purpose of this study was to investigate the stress magnitudes and distributions at the bone/implant interface in seven different analysis. MATERIAL AND MATHODS Seven different implant designs were used in this study. /M1 M2/M3/M4/M5/M6/M7/ /OD/3.75/3.75/3.75/3.75/3.75/3.75/3.75/ /ID/3.09/3.09/3.09/3.09/3.09/3.09/3.09/ /L/10/10/10/10/10/10/10/ /PH/0.6/0.6/0.6/0.6/0.7/0.5/0.5/ /SD/4.1/4.1/3.75/3.75/4.1/4.1/3.75/ /SH/1/1/1/0/1/1/1/ /BH/N/Y/N/N/N/N/N/ M : Model, OD : Outer diameter(mm), ID : Inner diameter(mm), L : Length(mm), PH : Pitch height(mm), SD : Shoulder diameter(mm), SD : Shoulder diatmeter(mm), SH : Shoulder height(mm), BH : Bottom hole. N : No, Y : Yes The bone models were 10mm high consisting of 2mm bicortical outer parts and 6mm cancellous inner part. The gold crown with titanium abutment connected to the implants to stimulate the implant prothesis in clinical situations. The total number of elements used in the largest FEM was 14410. The material prioperity values assignd in this study were made on the basis of previous published data. The load of 20Kg was given to each model at 0 o, 30 o, 90 o , direction. The finite element models wre generated and solved by using a computer-aided engineering program (I-DEAS, Structural Research Dynamics (Co). This pakage was installed on a SGI Indigo II 64-Mbyte main computer.
RESULTS
The model under 0 o direction load showed even stress distribution arounde all implants and small differences of maximum stress value at the bone/implant interface among different implant designs Model 7 showed the best stress distribution, maximum Von Mises stress, 1.854 MPa under this loading condition. Model 5 showed the worst stress distribution, maximum Von Mises stress, 2.711 MPa under this loading condition. The stress distributions of models under 30 o direction load are similar to those under 90 o direction load. Model 7 showed the best stress distribution, maximum Von Mises stress, 11. 49 MPa under this loading condition. Model 2 showed the worst stress distribution, maximum Von Mises stress, 22.87 MPa under this loading condition. The models under 90 o direction load showed the stress concenturation at the top parts of implants and had vary different maximum stress value according to different implant design. The results of maximum stresses at bone/implant interface under 90 o direction load are summerized below: /Maximum/Von/Mises/ /stress(MPa)/Rank/ /M1/41.02/6/ /M2/41.02/6/ /M3/35.30/5/ /M4/33.35/3/ /M5/33.95/4/ /M6/31.36/2/ /M7/20.25/1/
CONCLUSIONS
This study demonstrated that the implant design of small soulder diameter (3.75mm) with flat shoulder (1mm height) and small pitch height (0.5mm) showed the best stress distribution and favorable maximum stress values at the bone/implant interface under 0 degrees, 30 degrees and 90 degrees, direction

MeSH Terms

Bone Remodeling
Bone Resorption
Crowns
Finite Element Analysis*
Hydrogen-Ion Concentration
Indigo Carmine
Shoulder
Titanium
Indigo Carmine
Titanium