Abstract-Dental implants are used to retain and support fixed and removable dental prostheses. Over the past several decades, dental rehabilitation with implants has been widely accepted by dentists and patients because of its reliable functional and aesthetic results. In many clinical situations, local bone morphology requires dental implants that have a diameter that is significantly smaller than the typical implant diameters. In these cases, the fatigue life of the smaller diameter implants becomes a critical therapeutic parameter. According to particular situation of lateral incisor tooth, which has low space and also limited height due to the existence of the Sinus and Nerves in maxilla and mandible, respectively. Applications of various kinds of implants are being limited. This paper investigates the biomechanical behavior of a threaded dental implant/surrounding bone system under static and harmonic occlusal forces by using a three-dimensional finite element method for achieving the optimum diameter and length as the most effective parameters that are affected stress distribution in surrounding bones. The objective of this research was to select the optimum length and diameter for 26 different commercial dental implants by considering the variability in diameter and length and material of implants for missing upper/lower lateral incisor dental position by 3D finite element method. The influence of the length and diameter is considered after applying static, dynamic and fatigue loading for evaluation local/cycle failure probabilities in biodenta, CMI, DIO, implantium, and nobel implant systems. In this study, static dynamic and fatigue behaviors of the implants are investigated.Index Terms-Anterior mandible/maxilla, dental implant, finite element method, optimum diameter/length.

Abstract-Using osseointegrated dental implants allows restoration of completely or partially edentulous patients and success of this technique is linked to the connection between living bone and surface of load-bearing artificial structure, generally titanium-based. Many factors affect load transfer at the bone implant interface such as the type of loading, material properties of the implant and prosthesis, implant geometry, surface structure, implant design quality and quantity of surrounding bone, and nature of bone implant interface. The bone has the best resistance upon compressive loads, and lower resistance against tensile and shear loads. On the other hand, implants are subjected to various kinds of loads. Recently, to eliminate failures, caused by the threaded root-form implants have been introduced. In this paper, it is aimed to investigate how thread types can affect the amount, type of load and biomechanical responses induced in mandible/maxilla and implant-abutment complex by a finite element method. This problem signifies due to the usage of different kinds of thread forms made by different implant manufactures. Solid models have been developed for missing upper/lower lateral incisor dental position and 26 fixture models of 5-implant systems are made in to carry out analysis of lateral Incisor tooth of human by using FEA. The results of this paper will help in understanding the way in which stresses are distributed in dental structures. Consequently, static, dynamic and fatigue behaviors of implants are investigated.Index Terms-Dental implant, kinds of threads, kinds of loads, finite element method, lateral incisor position.

Abstract-Implants should be placed, paralleled to adjacent tooth and be vertically aligned with axial forces. However, in many clinical instances, achieving this may be impossible due to deficiencies in alveolar bone. Clinically, many implant cases with different angulation over the lower posterior area have been found. Therefore, implants must be placed in angled positions, complicating restoration using straight abutments but on the other hand, angled abutments have been introduced to correct such cases. As regards, the major load in the anterior region is being entered by tongue to teeth and according to particular situation of lateral incisor tooth that has low space and also height limitation due to the existence of the sinus and nerves in maxilla and mandible, respectively, therefore this study is evaluated effects of angled installation of implants and use of the angled abutment. This paper was to discover desirable installation of implant and compare the relation between design angle abutment, angled installation of implants and load distribution at the implant bone interface with vertical abutment implantation and evaluate how could decrease stress and promote better stress distribution on surrounding bone of single-unit dental implants. Therefore, 26 solid models of the lateral incisor were built up and were transferred to mesh models in FEM to perform a stress analysis. In this study, static, dynamic and fatigue behaviors of the implant are investigated.Index Terms-Dental implant, FEM, angle abutment, angled installation.