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Optimal selection of dental implant for different bone conditions based on the mechanical response

Roy S., Das M., Chakraborty P., Biswas J. K., Chatterjee S., Khutia N., Saha S., Roychowdhury A.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 2

11--20

EN

Bone quality varies from one patient to another extensively; also, Young’s modulus may deviate up to 40% of normal bone quality, which results into alteration of bone stiffness immensely. The prime goal of this study is to design the optimum dental implant considering the mechanical response at bone implant interfaces for a patient with specific bone quality. Method. 3D model of mandible and natural molar tooth were prepared from CT scan data while, dental implants were modelled using different diameter, length and porosity and FE analysis was carried out. Based on the variation in bone density, five different bone qualities were considered. First, failure analysis of implants, under maximum biting force of 250N had been performed; next, the implants, those survived were selected for observing the mechanical response at bone implant interfaces under common chewing load of 120N. Result. Maximum Von Mises stress did not surpass the yield strength of the implant material (TiAl4V). However, factor of safety of 1.5 was considered and all but two dental implants survived the design stress or allowable stress. Under 120N load, distribution of Von Mises stress and strain at the bone-implant interface corresponding to the rest of the implants for five bone conditions were obtained and enlisted. Conclusion. Implants, exhibiting interface strain within 1500-3000 microstrain range show the best bone remodelling and osseointegration. So, implant models, having this range of interface strains were selected corresponding to the particular bone quality. A set of optimum dental implants for each of the bone qualities were predicted.

2

Relationships between structure, density and strength of human trabecular bone

Mazurkiewicz A., Topoliński T.

Acta of Bioengineering and Biomechanics

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2009

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Vol. 11, nr 4

55-61

EN

The article deals with the examination of the relationships between density, structure parameters and strength of human trabecular bone. The tests were carried out on the samples taken from osteoporotic and coxarthrotic human femoral heads. The samples cylindrical in shape had the diameters of 10 mm and the height of 8.5 mm. During the tests with uCT scanner the parameters of a sample structure were measured. Bone mineral density (BMD) was measured as well. The samples were subjected to compression in order to assess the ultimate compression strength (fi)c. The relationships between two-element combinations (BMD and one of the structure parameters) and the compression strength of the samples have been studied. The consistence of the results for multiple regression and response surface regression was estimated based on the correlation coefficient R. For the examined pairs of parameters, the value R increased in the range of 7÷30% in comparison with the case where for the strength description only BMD was used. Additionally, the authors' own models of two-variable regression was calculated. The comparison of the results obtained for all models of regression based on the coefficient E proved the consistence of these results.

3

Analiza wskaźników oceny struktury kości in vitro i in vivo

Mazurkiewicz A., Topoliński T.

Przegląd Mechaniczny

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2005

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nr 6

40-44

PL

W pracy przedstawiono wybrane wskaźniki oceny struktury kości wykorzystywane w ocenie ich wytrzymałości in vivo, których wartości ustalane są w badaniach in vivo lub in vitro. Celem pracy była także ocena możliwości wykorzystania i przydatności pomiaru równomierności rozkładu gęstości (a więc i równomierności budowy strukturalnej) jako wskaźnika służącego do wstępnego określania wytrzymałości posiadanych preparatów kostnych przed próbami wytrzymałościowymi. Stwierdzono, że równomierność rozkładu gęstości w próbce jest wyższa dla kości koksartrycznych niż osteoporotycznych przy podobnej gęstości średniej struktury, a uzyskane rozkłady dla preparatów o porównywalnych gęstościach prześwietleniowych są istotnie różne.

EN

Selected indicators of bone structure evaluation have been presented. These indicators are used in bone strength evaluation in vivo (values of indicators are established in vitro or in vivo). The aim of the work was also estimation of utilization possibility and suitability of uniformity of density distribution uniformity measurements (uniformity of bone struc-ture) as an indicator for preliminary determination of bone samples strength. It was found that uniformity of density distribution in the sample is higher for coxarthritic bones than for osteoporotic ones with the same average density. Distribution of the uniformity for samples with comparable densities was essentially different.