A New Model to Study Fatigue in Dental Implants Based on Probabilistic Finite Elements and Cumulative Damage Model.

María Prados-Privado,José Antonio Bea,Juan Carlos Prados-Frutos,Sérgio A Gehrke,Rosa Rojo,José Luis Calvo-Guirado

doi:10.1155/2017/3726361

Abstract

The aim of this study was to predict the fatigue life of two different connections of a dental implant as in load transfer to bone. Two three-dimensional models were created and assembled. All models were subjected to a natural masticatory force of 118 N in the angle of 75° to the occlusal plane. All degrees of freedom in the inferior border of the cortical bone were restrained, and the mesial and distal borders of the end of the bone section were constrained. Fatigue material data and loads were assumed as random variables. Maximum principal stresses on bone were evaluated. Then, the probability of failure was obtained by the probabilistic approach. The maximum principal stress distribution predicted in the cortical and trabecular bone is 32 MPa for external connection and 39 MPa for internal connection. A mean life of 103 and 210 million cycles were obtained for external and internal connection, respectively. Probability cumulative function was also evaluated for both connection types. This stochastic model employs a cumulative damage model and probabilistic finite element method. This methodology allows the possibility of measured uncertainties and has a good precision on the results.

Highlights

Dental implants have been widely employed to replace missing teeth and have become routine elements of dental practice [1, 2] with a success rate higher than 90% [3]
Load transfer from implants to bone is influenced by the type of loading, the implant geometry, the shape and characteristics of the implant surface, and the quantity and quality of the surrounding bone [5, 6]
This paper applies a probabilistic methodology for two titanium dental implants, considering the variability in loads and Young’s modulus

Summary

Introduction

Dental implants have been widely employed to replace missing teeth and have become routine elements of dental practice [1, 2] with a success rate higher than 90% [3]. Despite this high success rate, dental implant failure can occur. Many studies have reported that the most crucial factor in dental implant fatigue is the geometry of the dental implant-abutment connection, a screw preload, dental implant fixation, and crown loading [8]. Abutment connection design affects the stress concentration in the surrounding bone [11]

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