PHOTOELASTIC STRESS ANALYSIS OF DISTAL EXTENSION REMOVABLE PARTIAL TELESCOPIC DENTURES WITH DIFFERENT CONICAL CROWNS Konusları Farklı Sonlu Hareketli Bölümlü Protezlerde Fotoelastik Stres Analizi

Distal extension removable partial denture (RPD) can cause stress on supporting hard tissues, which may lead to harmful effects. The purpose of this study is to investigate the pattern of these stresses over the residual alveolar ridge and alveolar bone around the abutment teeth by distal extension conical crown retained te lescop ic dentures (CCRTDs) with different taper angles using three dimensional photoelectric stress analysis. Thirty distal extension photoelastic mandible models with simulated periodontal ligaments and mucosa were divided into five groups. Vertical and oblique 5 0 N loading forces were applied over the dentures. These dentures involved one claps denture and four CCRTDs that conical crowns were planned mesial (M) and distal (D) 2°, M and D 4°, M 4° D 2° and M 2° D 4°. Fr i n g e s order values (N) of identified measurement points (A, B,C,..G) were measured and the data were evaluated by use Kruskal-Wallis and Mann-Whitney test. While the stress on the RPD with claps was concentrated on the point C where the distal abutment teeth and residual ridge meet, it was concentrated on the apex of abutment teeth in the CCRTDs. The stress under oblique loading increased significantly at point B, and under vertical loading at points A and C. Significant changes were observed between the points A, C, D and F in the second denture, points C and G in the 3, and B; in the 5, unlike the points in the 1 and 4 dentures