Presentation of a Mathematical Model to Predict Longterm Behaviour of Implants and their Prosthesis based on Probabilistic Fatigue

Research Article

J Dent & Oral Disord.2017; 3(1): 1050.

# Presentation of a Mathematical Model to Predict Longterm Behaviour of Implants and their Prosthesis based on Probabilistic Fatigue

¹Department of Medicine and Surgery, Faculty of Health Sciences, Rey Juan Carlos University, Madrid, Spain

²Applied Modelling and Instrumentation Group, Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza, Spain

*Corresponding author: Prados-Privado M, Department of Medicine and Surgery, Faculty of Health Sciences, Rey Juan Carlos University, Spain

Received: January 19, 2017; Accepted: February 15, 2017; Published: February 17, 2017

## Abstract

A key element for the success of a dental implant and its superstructures is related to bite forces, quality and quantity of jaw bones and implant design, among others. The goal of this study was to analyze load distribution in implantsupported dentures using probabilistic fatigue. 3D models were created employing the CAD software. An oblique load of 150 N with a 30° inclination in the linguo-buccal direction was applied. Calculations of stresses of the prosthesis and the bone were made. Then, the fatigue life (mean and variance) and the probability of failure were obtained.

Keywords: Finite element method; Probabilistic fatigue; Dental prosthesis

## Introduction

A key element for the success of a dental implant and its superstructures is related to bite forces, quality and quantity of jaw bones, implant design, implant surface texture and surgical procedures [1,2]. As Li detailed in his study [3], implant diameter and implant length are well accepted as an important factor in success because they directly influence the primary stability. Clinical observations indicate that the most common cause of implant failure is incomplete osseointegration [4]. Other two potential causes of implant failure are parafunctional habits and excessive occlusal forces [5] and the passive fit and seal between the implant and its abutment components [4].

The quality of the bone varies strongly depending on the anatomic region in the mandible [3,6]. Density of bone is an essential factor in treatment planning and clinical success and it determines the surgical approach, the implant design and the healing time [7,8]. Cortical thickness tends to decrease as its moves to the posterior region of the mandible but increase its trabecular porosity. Some clinical phenomenon can be understood with a good knowledge of the bone density in different areas of the maxilla and mandible [9]. Some studies have described the close relationship between the bone density and the success of dental implants where dental implants placed in low-density areas have a higher failure rate [9,10]. According to Chugh’s study [9], the density in the maxilla and mandible increases progressively from the midline to the posterior region because of the stress distribution.

Type of loading, material and geometric characteristic of the implant, bone-implant interface and the quantity and quality of the surrounding bone have influence on the load transfer from implants to surrounding bone [1,11,12].

The use of finite element method in the analysis of implant biomechanics furnishes many advantages in the simulation of complex clinical situations. This method makes possible, from a bioengineering point of view, to design and analyze dental implants with geometry that minimize the peak bone stress [11].

The aim of the present research was to evaluate the biomechanical behavior in the bone around the implant as well as to assess the stress transfer in the implant and it superstructures using a threedimensional finite element analysis and predict the long-term behavior of the whole structure.

## Finite element model

3D models were created employing the CAD software Solid works 2016 [Dassault Systemes, Solid Works Corp., Concord, MA, USA]. Dental implants were provided by the manufacturer and bone geometries were created employing Solid Works.

A D2 bone type [13] was simulated and their characteristics were obtained from Vootla and coworkers [14]. Dimensions used in the bone geometry ensure avoid any undesired boundary effects shows in Figure 1. Figure 2 details the prosthesis model analyzed in this study.