Photoelastic stress analysis of distal extension removable partial telescopic dentures with different conical crowns

Sonu serbest biten hareketli bölümlü protezler [HBP] sert ve yumuşak destek doku üzerinde strese sebep olabilir ve bu stres zararlı etkilere yol açabilir. Bu çalışmanın amacı 3 boyutlu fotoelastik stres analiz yöntemiyle farklı taper açılı konik tutuculu teleskopik sonu serbest biten HBP lerin ve kroşe tutuculu HBP’nin dişsiz alanlarında ve destek diş etrafındaki alveol kretinde oluşturduğu streslerin karşılaştırılmasıdır. Otuz adet periodontal mebranı ve mukozası olan sonu dişsiz sonlanan fotoelastik mandibular model 5 gruba ayrıldı. Beş farklı HBP; kroşe tutuculu, Mezial [M] ve distal [D] 2°, M ve D 4°, M 4° D 2° ve M 2° D 4° olacak şekilde dört adet farklı konik açılı teleskopik HBP olarak hazırlandı. Bu protezler üzerine dikey ve eğik 50 Newtonluk kuvvetler tek taraflı olarak uygulandı. Belirlenen ölçüm noktalarının (A. B, C,…G) frinç değerleri (N) olarak ölçüldü, Elde edilen değerler Kruskal Wallis ve Mann - Whitney testleriyle istatistiksel olarak değerlendirildi. Kroşe tutuculu HBP de stres yoğunluğu distaldeki destek diş ile dişsiz alveol kretinin birleşme yerinde (C noktasında) görülürken konik tutuculu teleskopik HBP lerde destek dişlerin kök uçlarında yoğunlaştı. Eğimli kuvvet B noktasında, dik kuvvet ise A ve C noktasında istatistiksel olarak anlamlı bir artış göstermiştir. 2. protezde A,C,D ve F, 3. protezde C ve G, 5. protezde B ölçüm noktaları arasında istatistiksel olarak anlamlı fark görülürken 1. ve 4. protezlerde ölçüm noktaları arasında anlamlı fark görülmedi.

Konuslari farkli 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 t e l e s copi c 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 3th, and B; in the 5th, unlike the points in the 1st and 4th dentures

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