Evaluation of the Effect of Crown/Implant Ratio on Stress Distribution in Dynamic Loaded Short Implants

Abstract

Background: The aim of this study is to investigate the stress distribution in surrounding bone tissue and implant caused by static and dynamic loaded short implants with different crown/implant ratios by finite element stress analysis method.

Methods: A total of 3 dental implants with a diameter of 4.1 mm and three different lengths (6 mm, 8 mm and 10 mm) were selected. These three implants are designed with three lower first molar metal-supported ceramic crowns on the crown/implant ratio of 1/1, 1.5 / 1 and 2/1 and implant-supported crowns were placed into the mandible model  and a total of 9 study models were obtained. For the evaluation of the effect of crown/implant ratio, the vertical and oblique functional forces applied to these models, the maximum and minimum principle stress values in the cortical and spongious bone, the Von Mises stress values on the implant and the fatigue values occurring in the implants were investigated by three dimensional finite element stress analysis method.

Results: Although the same amount of force was applied, there was a significant increase in stress levels in the parts of the implant system and in the bone tissue compared to the models with oblique loading. In all models, the increase in crown/implant ratio caused a significant increase in stress levels in the parts of the implant system and bone tissue.

Conclusions: The numerical values obtained within the limitations of this study showed that the crown/implant ratio affected the load transfer mechanisms and the clinical success times of the implants. It has been determined that 1/1 crown/implant ratio gives better results compared to other ratios in implant treatment which will be applied in one tooth deficiency in mandibular molar region. The increase in crown/implant ratio resulted in increased stress levels and shortening the clinical success times of implants.

Keywords: Dynamic loading, short implant, crown/implant ratio, finite element stress analysis.

Keywords

• Dynamic loading,short implant,crown/implant ratio

Dinamik Yükleme Yapılan Kısa İmplantlarda Kron/İmplant Oranının Stres Dağılımına Etkisinin İncelenmesi

Abstract

Amaç: Bu çalışmanın amacı farklı kron/implant oranına sahip kısa implantlar üzerine uygulanan statik ve dinamik yüklerin implantı çevreleyen kemik doku ve implantta meydana getirdiği stresin sonlu elemanlar stres analiz yöntemiyle incelenmesidir. 

Gereç ve Yöntemler: Çalışmada, 4.1 mm çapında ve üç farklı uzunlukta (6 mm, 8 mm ve 10 mm) toplam 3 adet dental implant seçilmiştir. Bu üç implantın üzerine kron/implant oranı 1/1, 1.5/1 ve 2/1 olacak şekilde üçer adet alt birinci molar metal destekli seramik kron bilgisayar ortamında tasarlanmış ve implant destekli kronlar yine bilgisayar ortamında mandibula modeline yerleştirilerek toplam 9 adet çalışma modeli elde edilmiştir. Elde edilen bu modellere, vertikal ve oblik fonksiyonel kuvvetler uygulanarak, kortikal ve spongioz kemikte oluşan maksimum ve minimum asal stres değerlerine, implantta oluşan Von Mises stres değerlerine, implantlarda meydana gelen yorulma değerlerine kron/implant oranının etkisi üç boyutlu sonlu elemanlar stres analiz yöntemiyle incelenmiştir.

Bulgular: Aynı miktarda kuvvet uygulanmasına rağmen, oblik yükleme yapılan modellerde dik yükleme yapılan modellere oranla implant sistemini oluşturan parçalarda ve kemik dokuda stres seviyelerinde belirgin bir artış olmuştur. Tüm modellerde, kron/implant oranındaki artış implant sistemini oluşturan parçalarda ve kemik dokuda stres seviyelerinde belirgin bir artışa neden olmuştur.

Sonuçlar: Bu çalışmanın limitleri dahilinde elde edilen sayısal değerler, kron/implant oranının yük transfer mekanizmalarını ve implantların klinik başarı sürelerini etkilediğini göstermiştir. Mandibular molar bölgede tek diş eksikliklerinde uygulanacak implant tedavisinde 1/1 kron/implant oranının diğer oranlara göre daha iyi sonuçlar verdiği tespit edilmiştir. Kron/implant oranındaki artış stres miktarlarının artmasına ve implantların klinik başarı sürelerinin kısalmasına neden olmuştur.

Anahtar Kelimeler: Dinamik yükleme, kısa implant, kron/implant oranı, sonlu eleman stres analizi

Keywords

• Dinamik yükleme,kısa implant,kron/implant oranı

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