탄성 가철성 국소의치의 교합면 레스트 유무에 따른 광탄성 응력 분석

Abstract

ABSTRACT

Photoelastic stress analysis of the flexible removable partial denture with and without occlusal rest

Hwang, Young-Phil, D.D.S., M.S.D. Advisor : Prof. Kay, Kee-Sung, D.D.S., M.S.D., Ph.D. Department of Dentistry, Graduate School of Chosun University.

The conventional clasp unilateral removable partial denture(URPD), the flexible URPD without occlusal rest, and the flexible URPD with occlusal rest were fabricated in the missing area of the lower right 1st and 2nd molar, and the stress distribution occuring at the alveolar bone around the abutment tooth and the residual alveolar ridge after applying the vertical load and the 15˚ oblique load of 60N was analyzed using the three dimensional photoelastic stress method. The following results were obtained :

1. In case of vertical load, the flexible URPD without occlusal rest transmitted more stress to the alveolar bone around the terminal abutment and the residual alveolar ridge than the conventional clasp URPD, but the flexible URPD with occlusal rest transmitted less stress than the conventional clasp URPD.

2. In case of oblique load, the flexible URPD with and without occlusal rest transmitted more stress to the alveolar bone and the residual alveolar ridge than the conventional clasp URPD.

3. The flexible URPD with occlusal rest transmitted the stress totally not only to the alveolar bone around the terminal abutment and the residual alveolar ridge but also to the long axis of the abutment.

4. The flexible URPD with occlusal rest transmitted less stress totally to the alveolar bone around the terminal abutment and the residual alveolar ridge than the flexible URPD without occlusal rest.

As a result of this study, it is thought that the flexible URPD with occusal rest is clinically useful because it transmits less stress to the alveolar bone around the terminal abutment and residual alveolar ridge, and it must be considered to prepare the proper occlusal rest seat and to do the occlusal adjustment to remove the harmful occlusal interference during the lateral movement at the delivery to acquire better clinical results.