Mandibular 2 implant destekli overdenture protezlerde ataşmanlar üzerine gelen streslerin değerlendirilmesi

Objectives: The aim of this study was to evaluate the effect of implant locations on the stress around the two different attachment systems in mandibular two-implant overdentures.Materials and Methods: The data obtained from Visible Human Project were modified with the use of VRMESH and Rhinoceros 4.0 software to establish a 3D mandible model with 2 mm cortical bone covering the trabecular bone and 2 mm mucosae. 3D models (totally 6 models) of mandibular two-implant overdenture were designed according to different implant locations [lateral-lateral (LL), lateral-canine (LC), lateral-first premolar (LP)] and attachment systems [ball (BA), locator (LA)]. Foodstuff was used for occlusal loading (100N) and to simulate different biting configurations, foodstuff was positioned on incisors (anterior) and between the second premolar and first molar (posterior) bilaterally. The finite element analysis was performed by ALGOR FEMPRO software and von Mises stresses on attachments were evaluated.Results: For symmetric configuration (LL), there was more von Mises stress on BA compared to LA when foodstuff was positioned posteriorly. For asymmetric configurations (LC and LP), when the implant in the asymmetric side was positioned more posteriorly, von Mises stresses increased on both BA and LA of the implant positioned in the opposite side. In LC configuration, on BA higher von Mises stresses detected when compared to LA, whereas in LP configuration the higher stresses determined on LA when foodstuff was positioned posteriorly.Conclusions: In LL and LP configurations, LA showed lower stresses, which should lead the clinician to choose the appropriate attachment system according to the individual clinical situation

Objectives: The aim of this study was to evaluate the effect of implant locations on the stress around the two different attachment systems in mandibular two-implant overdentures.

Materials and Methods: The data obtained from Visible Human Project were modified with the use of VRMESH and Rhinoceros 4.0 software to establish a 3D mandible model with 2 mm cortical bone covering the trabecular bone and 2 mm mucosae. 3D models (totally 6 models) of mandibular two-implant overdenture were designed according to different implant locations [lateral-lateral(LL), lateral-canine(LC), lateral-first premolar(LP)] and attachment systems [ball(BA), locator(LA)]. Foodstuff was used for occlusal loading (100N) and to simulate different biting configurations, foodstuff was positioned on incisors (anterior) and between the second premolar and first molar (posterior) bilaterally. The finite element analysis was performed by ALGOR FEMPRO software and von Mises stresses on attachments were evaluated.

Results: For symmetric configuration (LL), there was more von Mises stress on BA compared to LA when foodstuff was positioned posteriorly. For asymmetric configurations (LC and LP), when the implant in the asymmetric side was positioned more posteriorly, von Mises stresses increased on both BA and LA of the implant positioned in the opposite side. In LC configuration, on BA higher von Mises stresses detected when compared to LA, whereas in LP configuration the higher stresses determined on LA when foodstuff was positioned posteriorly.

Conclusions: In LL and LP configurations, LA showed lower stresses, which should lead the clinician to choose the appropriate attachment system according to the individual clinical situation.

 

 ÖZET

Amaç: Bu çalışmanın amacı, mandibular 2 implant destekli overdenture protezlerde farklı lokalizasyonlarda yerleştirilmiş implant üzerindeki 2 farklı tip ataşmana gelen streslerin değerlendirilmesi.

Gereç ve Yöntem: “Visible Human Project” dataları VRMESH ve Rhinoceros 4.0 yazılımlarıyla, 2 mm mukoza ve 2 mm kortikal tarafından çevrelenmiş trabeküler kemik özelliklerine sahip 3 boyutlu (3B) mandibular modeli oluşturuldu. Mandibular 2 implant destekli overdenture protezi simüle eden 3B modeller (toplam 6 adet) farklı implant lokalizasyonları ve farklı ataşman sistemleri kullanılarak tasarlandı. Modeller üzerine oklüzal yüklemeler (100N), yarım yuvarlak sert materyal(YYSM) ile farklı fonksiyonel hareketleri (çiğneme, ısırma) simüle edebilmek için farklı konumlardan yapılmıştır. Sonlu elemanlar analizi ALGOR FEMPRO yazılımı ile yapılıp, ataşmanlara gelen stresler Von Mises değerleri ile değerlendirilmiştir..

Bulgular: Simetrik lokalizasyonlarda (LL), posterior bölgeden yapılan yüklemeler sonucunda BA’ya gelen stresler LA’ya gelen streslerden daha fazladır. Asimetrik konfigürasyonlarda (LC ve LP), sol taraftaki implant posteriora doğru konumlandıkça, diğer tarafta bulunan implant üzerindeki hem BA hem de LA’da Von Mises stresleri artmıştır. YYSM posterior yerleştirildiğinde, LC konfigürasyonunda BA’da, LA’ya göre daha yüksek Von Mises stresleri gözlenirken, LP konfigürasyonlarda LA’da daha yüksek stresler tespit edilmiştir

Sonuçlar: LL ve LP konfigürasyonlarında, LA daha düşük stres değerleri göstermiştir. Bu sonuç, klinisyenlere implant destekli overdenture protez yaparken seçecekleri ataşman türü hakkında öncülük edecektir.