골유착성 임프란트와 자연치를 이용한 고정성 국소의치에서 응력분산 및 충격흡수에 관한 유한요소법적 응력분석

Abstract

[한글]

골유착성 임프란트와 자연치를 이용한 고정성 국소의치에서 정하중 및 동하중으로 인하여 지지 골조직에 발생하는 응력을 보다 효율적으로 분산, 완화시킬 수 있는 방법을 비교 연구하고자 이차원 유한요소법적 응력분석을 이용하여, 첫째, 정하중시 보철물 고정나사의 설계 유무 및 보철물 고정나사의 물리적 성질의 변화, 상부 보철물의 물리적 성질의 변화, 그리고 내가동연결장치(intramobile connector)의 사용등에 따른 응력분산 효과를 상호 비교 분석하고, 둘째, 동하중시 내가동연결장치 및 상부 보철물 교합면의 복합레진 피개에 따른 충격흡수 효과를 비교 분석한 결과 다음과 같은 결론을 얻었다.

1. 정하중시 보철물 고정나사의 사용 및 보철물 고정나사의 굴성증가, 또는 상부 보철물의 굴성증가로 인하여 임프란트 경부 피질골에 응력이 국소적으로 증가되었으며, 자연치 주위 지지골에서는 뚜렷한 응력변화가 관찰되지 않았다.

2. 정하중시 내가동연결장치의 사용으로 임프란트 경부 피질골에 집중되는 응력이 크게 감소되었으며, 자연치 주위 지지골에 약간의 응력이 증가되었다.

3. 동하중시 교합면의 복합레진 피개 또는 내가동연결장치의 사용으로 임프란트 주위 지지골에 발생하는 응력이 감소되었으며, 복합레진 피개가 내가동연결장치 보다 충격흡수 효과가 큰 것으로 나타났다.

A FINITE ELEMENT STRESS ANALYSIS OF THE STRESS DISTRIBUTI0N AND THE SHOCK

ABSORPTION IN AN OSSEOINTEGRATED IMPLANT-NATURAL TOOTH SUPPORTED FIXED PARTIAL

DENTURE

Chang Mo Jeoung

D.D.S., M.S.D. Department of Dental Science, Graduate School,

Yonsei University

(Directed by Ho Yong Lee, D.D.S., M.S.D., Ph.D.)

The long-term success of any dental implant is dependent upon the optimization of

stresses which occur during oral function and parafunction. Especially, it has been

suggested that there is an unique set of problems associated with joining an

osseointegrated implant and a natural tooth with a fixed partial denture. For this

particular case, although many literatures suggest different ways to avoid high

stress concentrations on the bone surrounding the implant under static and dynamic

loading cunditions, but few studies on the biomechanical efficacy of each assertion

have been reported.

The purpose of this investigation was to evaluate the efficacies of clinically

suggested methods on stress distribution under static load and shock absorption

under dynamic load, using two dimensional finite element method.

In FEM models of osseointegrated implant-natural tooth supported fixed partial

dentures, calculations were made on the stresses in surrounding bone and on the

deflections of abutments and superstructure, first, to compare the difference in

stress distribution effects under static load by the flexure of fastening screw or

prosthesis, or intramobile connector, and second, to compare the difference in the

shock absorption effects under dynamic load by intamobile connector or occlusal

veneering with composite resin.

The results of this analysis suggest that:

1. Under static load condition, using an implant design with fastenign screw

connecting implant abutment and prosthesis or increasing the flexibility of

fastening screw, or increasing the flexibility of prosthesis led to the increase in

height of peak stresses in cortical bone surrounding the implant, and has little

effect on stress change in bone around the natural tooth.

2. Under static load condition, intramobile connector caused the substantial

decrease in stress concentration in cortical bone surrounding the implant and the

slight increase in stress in bone around the natural tooth.

3. Under dynamic load condition, both intramobile connector and composite resin

veneering showed shock absorption effect on bone surrounding the implant and

composite resin veneering had a greater shock absorption effect than intramobile

connector.

[영문]

The long-term success of any dental implant is dependent upon the optimization of stresses which occur during oral function and parafunction. Especially, it has been suggested that there is an unique set of problems associated with joining an osseointegrated implant and a natural tooth with a fixed partial denture. For this particular case, although many literatures suggest different ways to avoid high stress concentrations on the bone surrounding the implant under static and dynamic loading cunditions, but few studies on the biomechanical efficacy of each assertion have been reported.

The purpose of this investigation was to evaluate the efficacies of clinically suggested methods on stress distribution under static load and shock absorption under dynamic load, using two dimensional finite element method.

In FEM models of osseointegrated implant-natural tooth supported fixed partial dentures, calculations were made on the stresses in surrounding bone and on the deflections of abutments and superstructure, first, to compare the difference in

stress distribution effects under static load by the flexure of fastening screw or prosthesis, or intramobile connector, and second, to compare the difference in the shock absorption effects under dynamic load by intamobile connector or occlusal veneering with composite resin.

The results of this analysis suggest that:

1. Under static load condition, using an implant design with fastenign screw connecting implant abutment and prosthesis or increasing the flexibility of fastening screw, or increasing the flexibility of prosthesis led to the increase in height of peak stresses in cortical bone surrounding the implant, and has little

effect on stress change in bone around the natural tooth.

2. Under static load condition, intramobile connector caused the substantial decrease in stress concentration in cortical bone surrounding the implant and the slight increase in stress in bone around the natural tooth.

3. Under dynamic load condition, both intramobile connector and composite resin veneering showed shock absorption effect on bone surrounding the implant and composite resin veneering had a greater shock absorption effect than intramobile connector.