Proceedings of COBEM 2011 21 st Brazilian Congress of Mechanical Engineering Copyright © 2011 by ABCM October 24-28, 2011, Natal, RN, Brazil ANALYSIS OF THE STRESS DISTRIBUTION GENERATED BY MASTICATORY LOADS ON DENTAL IMPLANTS USING FINITE ELEMENT METHOD. Selma Hissae Shimura da Nóbrega (1) , nobrega@ufrnet.br Gutemberg Morais Serrano (2) , guto_140@globo.com Arthur Álax de Araújo Albuquerque (2) , arthuralax@yahoo.com.br Álvaro Benevides (3) , alvarobenevides@bol.com.br UFRN – CT, Av. Senador Salgado Filho, 3000 – Lagoa Nova - Natal/RN (1) Professor, Programa de Pós-graduação em Engenharia Mecânica (2) Undergraduate students, Civil Engineering (3) Graduated student, Programa de Pós-graduação em Engenharia Mecânica Abstract. The evaluation of the biomechanical behavior of dental implants structures and their interaction with cortical and cancellous bones are of extremely importance for dentists. During years, these professionals have had only clinical histories, accompaniments or clinical trials of high costs to evaluate these implants structures. Nowadays, however, computational analysis based on Finite Element Method has proven its efficiency and its reliability when studying the following aspects: stresses that arise from the masticatory loads on dental implants and their distribution in adjacent structures; the location of implants; proposal of new geometries, implants composition and structure, and prosthetic components, prosthetic planning, and interaction with surrounding tissues. This work deals with linear elastic analysis of implants when submitted to specific masticatory action and evaluates new implants and threads geometries in order to mitigate the effects of bone loss typically observed in the neck of the implant and to provide a better stress distribution in cancellous bone. For this purpose, three implants geometries with different threads geometries were analyzed using 2D finite elements for Plane Strain. The results show that cylindrical implants with rectangular threads have a better performance on stress distribution. Keywords: finite element method, bioengineering, biomechanics, dental implants. 1. INTRODUCTION In 2010, the World Health Organization published that almost 50% of Brazilians between the ages of 35 and 44 have lost, at least, 12 teeth and 80% of the elderly have less than 20 teeth. To solve this problem it is necessary not only an oral health care orientation for those with lower educational level and financial conditions, but also provide a cost reduction of the process and the refinement of the implants insertion techniques. Araújo et al. (2008) have described that implants are used to replace teeth roots and usually made, commercially, of pure titanium, a bioinert and biocompatible material. The bone-implant system is basically composed by the implant , the prosthetic component that includes abutment and its screw, the prosthesis formed by copping and crown, and the supporting bone formed by cortical bone and cancellous bone. Figure 1 – Tooth structure and bone implant system. (adapted from http://www.icoc.com.br/outros2.php) Figure 1 shows, on the left, the tooth structure with a thin tissue involving its root. It is called periodontal ligament whose function is to protect the root of sudden and intense masticatory forces and, moreover, it is responsible for producing a natural damping effect. This tissue does not exist in an implant system because there is a direct contact between the component and the surrounding bone tissue. In this case, when these natural and artificial elements are adapted to each other, it is said that the implant is osseointegrated . Many factors influence the osseointegration process. In fact, it does not occur immediately after implant insertion, but six or eight weeks later and during all life. The osseointegration depends on: blood supply, no trauma occurrence