上顎乳中切齒 治療時의 應力分析 = Stress Analysis in Restorative Procedures on Upper Primary Central incisor

다국어 초록 (Multilingual Abstract)

To study the stress analysis in restorative procedures of upper primary central incisor, 4 type of finite elements were constructed according to the anatomy of labiolingual cross-section of upper primary central incisor and supporting structures.
Each type of model was designed respectively according to the treatment methods : no treatment (Model 1), class Ⅲ cavity & resin restoration (Model 2), pulpotomy (Model 3), and pulpectomy (Model 4)
1 ㎏ force was applied as follow :
1) vertical load on incisal eage
2) horizontal load on labial surface
The displacements and stresses of tooth and supporting structures were analyzed to investigate the influence of the loading condition and the type of restorative procedures.
The results were as follows :
1. As for displacement, the vertical force caused downward displacement ; the horizontal force affected some prominent lingual displacement, of which the rotational center was located at near the root apex.
2. Both compressive and equivalent stress caused by the vertical force showed the maximal value downward at the loading point, they decreased downward along the tooth axis, and finally a bit of stress was concentrated at the root apex.
3. Horizontal force produced the prominently high compressive and tensile stress at the loading point and adjacent alveolar bone.
Compressive stress were observed to show some increase at the labial alveolar bone and tensile stress were observed at the lingual alveolar bone near to the root surface, respectively.
In addition, equivalent stress showed the distribution similar to principal stress.
4. Natural tooth and restorative tooth - which were restored with composite resin after class Ⅲ preparation - showed no difference of stress distribution. However, pulptomized and pulpectomized tooth showed the increase of stress at the ZPC base.