The long-term success of dental implants in various clinical situations depends to a large extent on the quality of the implant and bone bond (Adell et al. 1981; Albrektsson et al. 1981; Zarb & Schmitt 1990). Because of a higher ratio of compact to trabecular bone in the mandible, implants inserted into the anterior mandible have higher survival rates than implants placed in the posterior maxilla (Adell et al. 1981; Lazzara et al. 1996; Alsaadi et al. 2007). Primary implant stability is a prerequisite for implant survival, thus preventing the formation of a connective tissue layer between implant and bone, consequently ensuring bone healing (Branemark et al. 1977; Meredith 1998; Lioubavina-Hack et al. 2006). The results of various clinical and experimental studies suggest that several factors influence the primary stability of dental implants, such as (1) the quantity and density of the bone available at the implant site (Sevimay et al. 2005); (2) the surgical technique (the relation between drill size and implant size) (Sennerby & Roos 1998; Buchter et al. 2003); and (3) the macroscopic and microscopic morphology of the implant used (Hansson 1999; O’Sullivan et al. 2004; Saadoun et al. 2004).
The aim of the present study is to quantitatively analyze the interrelationship among variables of 1. cortical thickness of bone; 2. % distribution of trabecular bone; 3. average Housfield units; 4. Thread design; 5. Implant surface area on the primary implant stability, which will be measured by implant insertion torque, implant displacement, resonance frequency analysis and histomorphometric analysis.