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Mechanical response at peri-implant mandibular bone for variation of pore characteristics of implants: A Finite Element Study

Sarkar Sulagna, Sahu Tikeshwar Prasad, Datta Arijit, Chandra Nimesh, Chakraborty Arindam, Datta Pallab, Majumder Santanu, Chowdhury Amit Roy

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 2

83--93

EN

In this paper, the mechanical response of generic dental implants having calculated porosities with varying pore-sizes has been evaluated. The purpose of this study was to compare the developed stress-strain of designed porous implants (i.e., stress at the implant and strain at the peri-implant bone) with that of the non-porous implant. Methods: 3D model of a mandible was prepared from CT scan data and nine generic dental implant models have been designed having 10%, 20%, and 30% porosity with 500, 700, and 900 micron pore size along with a non-porous model for carrying out FE analyses. First, failure analyses of implants, under a biting force of 250 N have been performed. Next, the remaining implants have been further evaluated under average compressive chewing load of 100 N, for mechanical responses at bone-implant interface. Results: Von Mises strain at the peri-implant mandibular bone increases with the increase in percentage porosity of the implant material and maximum implant stress remained much below the yield stress level. Conclusion: Implant stiffness and compressive strength vary as a function of porosity and pore size. Strain obtained on the peri-implant bone is sufficient enough to facilitate better bone growth with the 700 micron pore size and 30% porosity, thus reducing the effect of stress shielding.

2

Mock-up in hip arthroplasty pre-operative planning

Zanetti E. M., Bignardi C.

Acta of Bioengineering and Biomechanics

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2013

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Vol. 15, no. 3

123--128

EN

The correct estimation of stem boundary conditions in hip arthroplasty cannot be performed simply by subtracting the prosthesis volume from the bone volume: the stem implant path needs to be taken into account. Digital mock-up is a technique commonly applied in the automotive field which can be used for this aim. Given a certain femur, a stem, and an implantation path, the volume of the removed bone stock can be evaluated, as well as the final contact area between the bone and the stem, and, section by section, the residual cortical bone thickness. The technique proved to be useful: if the stem implant path is not considered, the removed bone stock volume can be underestimated up to 6%, while the contact area extension can be overestimated up to 28%. On the whole, a new methodology has been set up and tested, which can be usefully employed to accurately establish stem boundary conditions in the pre-operative planning stage, and in order to perform a reliable structural stress analysis. The methodology implemented here by experienced researchers can be made available to surgeons, setting up an apposite software suite.

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Zagadnienie biomechanicznej biokompatybilności kości i materiałów konstrukcyjnych implantów ortopedycznych w świetle współczesnego dwufazowego porosprężystego modelu tkanki kostnej

Winiecki M.

Eksploatacja i Niezawodność

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2004

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nr 2

74-79

PL

Konstrukcję układu biomechanicznego kość-implant, np.: konstrukcję sztucznego stawu biodrowego tworzącą konstrukcję nośną organizmu charakteryzuje zespół cech materiałowych, geometrycznych i dynamicznych, dobranych ze wzglądu na osiągniecie założonego celu. Analiza zagadnienia zgodności strukturalno-biomechanicznej kości i biomateriału wszczepu rozpatrzona na podstawie nowego dwufazowego porosprezystego modelu tkanki kostnej może dostarczyć nowych przesłanek odnośnie zwiększenia poziomu niezawodności wszczepianych sztucznych stawów i wydłużenia okresu ich eksploatacji bez konieczności reimplantacji. Praca przedstawia istotę porosprezystego modelu tkanki kostnej oraz własne badania właściwości mechanicznych kości.

EN

The construction of biomechanical system bone-implant e.g. construction of artificial hip joint, composing carrying construction of living organism, is characterized by set of material, geometrical and dynamic attributes, selected to fulfil required assumptions. The principal goal of biomechanical research of orthopaedic implants is to provide durability and stability of considered biomechanical system. Biomaterials assigned for orthopaedic implants and for bone graft substitutes have to satisfy series of requirements connected not only with biological response of living tissue. Analysis of structural-biomechanical compatibility of bone tissue and constructional materials of bone implant considered on the grounds of modem two-phase poroelastic model for bone tissue might afford additional knowledge required for increasing of reliability of discussed constructions and extension of its operating period without necessity of reimplantation. This paper presents the essence of the two-phase poroelastic model of bone illustrated with owns research of mechanical properties of bone.

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Contact problems with friction, adhesion and wear in orthopaedic biomechanics. Part I - general developments

Rojek J., Telega J. J.

Journal of Theoretical and Applied Mechanics

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2001

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Vol. 39 nr 3

655-677

EN

The present paper is a continuation of the contribution by Rojek and Telega (1999). An alternative adhesion law is used to the study of the bone-implant interface. Various problems related to the bone-implant interface are discussed.

PL

Zagadnienia kontaktowe z tarciem, adhezją i zużyciem w biomachanice ortopedycznej. Część I - Rozważania ogólne. Niniejsza praca stanowi kontynuację wcześniejszej pracy autorów, por. Rojek i Telega (1999). Zastosowano alternatywny model adhezji dla opisu interfazy kość-implant. Przedyskutowano równierz szereg zagadnień związanych z tą interfazą.