Comparison of stress distribution in partially and completely edentulous mandibles around splinted and non-splinted implant prostheses: A finite element study

Article type: Research Article

Authors: Ozeki, K.^a; | Nishio, H.^a

Affiliations: [a] Major in Mechanical Systems Engineering, Graduate School of Science and Engineering, Ibaraki University, Nakanarusawa, Hitachi, Ibaraki, Japan

Correspondence: [*] Corresponding author: K. Ozeki. Tel.: +81 294 38 5040; Fax: +81 294 38 5047; E-mail: kazuhide.ozeki.365@vc.ibaraki.ac.jp

Abstract: BACKGROUND:In some treatments using multiple dental implants, the implants are inserted in the bone with splinted or non-splinted implant prostheses. There are some reports about the influence of the splinted and non-splinted implants on stress distribution in the bone using the finite element method (FEM), and there is a controversy in the literature regarding whether the splinted or non-splinted implants prostheses reduce the stress generated on the implant-surrounding bone more efficiently. Additionally, the simple shape of the jaw bones with limited bone area was used for FEM analysis in many studies at the expense of accurate analysis. OBJECTIVE:The aim of this study was to evaluate the difference in stress distribution in the bone between the splinted and non-splinted implants, and between completely and partially edentulous mandibles. METHODS:The implants were inserted in the first premolar, second premolar, and first molar regions of the partial and complete mandibles, and the splinted and non-splinted crowns were attached to the implants. Vertical load (100 N) or oblique load (70 N, 30° from its long axis towards the lingual) was applied on the first premolar. RESULTS:When vertical load was applied to the partially edentulous mandible model, the stress was concentrated intensively on the cortical bone around the first premolar regardless of whether splinted or non-splinted implants were used. On the other hand, the vertical load applied to the completely edentulous mandible model caused the stress to be concentrated intensively on the cortical bone around the first premolar with non-splinted implants. With respect to the oblique load, the stress was concentrated intensively on the cortical bone around the first premolar only with the non-splinted implants, in both the partial and complete mandibles. CONCLUSION:This study shows the different stress distributions of the cortical bone around the implants between the partial and complete mandible. This indicates that the complete mandible should be used for the analysis of bone stress distribution around the implants using FEM.

Keywords: Finite element method, splinted, non-splinted, dental implant

DOI: 10.3233/BME-201077

Journal: Bio-Medical Materials and Engineering, vol. 31, no. 1, pp. 19-33, 2020