VERTICAL AUGMENTATION OR SHORT IMPLANT?’: A FINITE ELEMENT ANALYSIS STUDY

Background & Aim: Advanced surgical treatment options or short implants can be considered in cases of insufficient bone volume. The purpose of this study was to compare the intensity, distribution and localization of stress on implants, abutments and peri-implant cortical and cancellous bone in response to vertical and oblique loading forces in severely atrophic mandible models treated with alternative treatment protocols (augmentation procedure or short implants). Materials and Methods: Three different bone models were generated: a standard model, a reconstructed model and an atrophic model. In the standard and reconstructed mandible models, a 10-mm implant was placed in the mandibular 1st molar region, and the crown height space was accepted as 8 mm. In the atrophic model, a 6-mm implant was placed in the mandibular 1st molar region. The maxillary occlusal plane was constricted to standardize the total implant and crown height in all of the models. Thus, the crown height space was accepted as 12 mm in the atrophic model. Vertical loads (150 N) were applied to the central fossa of the crown, and oblique loads (50 N) were applied to the mesiobuccal cusp of the crown. The von Mises stresses and maximum principal (tensile) and minimum principal (compressive) stresses on each model were evaluated using finite element analysis. Results: The atrophic and reconstructed mandible models had similar results in terms of stress intensity, distribution and localization. Conclusion: From the mechanical point of view, short dental implants can be considered as an alternative treatment option to reconstructive surgery.

İLİAK KEMİK GREFTİ İLE REKONSTRÜKTE EDİLMİŞ İLERİ DERECEDE ATROFİK MANDİBULA MODELLERİ ÜZERİNDEKİ STRES DAĞILIMININ SONLU ELEMANLAR ANALİZİ İLE DEĞERLENDİRİLMESİ

Amaç: Kemik hacminin yetersiz olduğu durumlarda ileri cerrahi tedavi seçenekleri ve kısa implantlar düşünülebilir. Bu çalışmanın amacı; mandibulanın ileri derecede rezorpsiyona uğradığı durumlarda, 2 farklı tedavi yaklaşımı (ogmentasyon ve kısa implantlar) uygulandığında, vertikal ve açılı kuvvetler karşısında; implant ve dayanak üzerinde oluşan ve implantı çevreleyen kortikal ve süngerimsi kemikte oluşan streslerin şiddetlerini, dağılımlarını ve lokalizasyonlarını karşılaştırmaktır. Gereç ve Yöntem: Çalışmada; standart, rekonstrükte edilmiş ve atrofik mandibula modeli olmak üzere 3 farklı kemik modellenmiştir. Standart ve rekonstrükte mandibula modelinde, 1. molar bölgesine, 10 mm uzunluğunda implant yerleştirilmiş ve kron yüksekliği mesafesi 8 mm olarak kabul edilmiştir. Atrofik modelde 1. molar bölgesine, 6 mm uzunluğunda implant yerleştirilmiştir. İmplant uzunluğu ve kron yüksekliği mesafesi toplamını standardize etmek amacıyla maksiller okluzal düzlem sabit tutulduğundan atrofik modelde kron yüksekliği mesafesi 6 mm olarak kabul edilmiştir. Vertikal kuvvetler (150 N) kronun santral fossasından, oblik kuvvetler (50 N) kronun meziobukkal cuspından uygulamıştır. Von Mises stres, maksimum gerilim ve minimum sıkışma stresleri sonlu elemanlar analizi yöntemi ile değerlendirilmiştir. Bulgular: Rekonstrükte mandibula modeli ile atrofik mandibula modelinde ölçülen stres değerlerinin, dağılımının ve lokalizasyonunun birbirine yakın değerler olduğu görülmüştür. Sonuç: Mekanik açıdan bakıldığında, kısa dental implantlar rekonstrüktif cerrahiye alternatif olabilir.

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