The contact area of bone-implant interfaces places a major influence on the osseointegration of the bone to the dental implant body. The attachment between implant body and bone is vital in securing the placement of a dental implant system. As observed in many past clinical findings, the survival of dental implant is strongly dependent on the initial stability of implant body and long-term osseointegration that provide lasting incorporation in the bone media. The purpose of this study is to examine the effect of different implant thread profiles on stress dissipation within the adjacent bone via three-dimensional (3-D) finite element analysis (FEA). An image-processing software was utilised to develop a 3-D model of mandible which reconstructed from computed tomography (CT) image datasets. The selected region of interest was the left side covering the second premolar, first molar, and second molar regions. The bone model consisted of compact (cortical) and porous (cancellous) layers. Four generic models of crown and abutment, and four implant bodies with different designs of thread profile - reverse buttress (RB), buttress (B), sinusoidal (Si), and square (Sq) were created using computer-aided design (CAD) software and all models were then analysed via 3D FEA software. The top surface of first molar crown was applied with the occlusal forces of 114.6N, 17.2N, and 23.4N in the axial, lingual, and mesio-distal directions, respectively. All planes of the mandibular bone model were fixedly constrained. The result showed that implant body with RB thread design promoted the most promising stress outcomes as compared to others. This is due to the high total contact area of bone-implant interfaces which increases the implant motion resistance resulting in favourable stress level generated.
