RESUMEN
STATEMENT OF PROBLEM: Adequate bone quality and quantity were important to achieve initial stability and to prevent early failures. However there were few published data available regarding the actual effect of dimensional change in implant geometry on initial stability. PURPOSE: The purpose of the current study was to investigate the influence of diameter and length changes on initial stability of implants. MATERIAL AND METHODS: Four types of dummy bone (D1, D2, D3 and D4) consisted of cortical and cancellous layers with different thickness were simulated. Implants which had similar surface area to each other (3.5 x 13.0-mm, 4.0 x 11.5-mm, 4.5 x 10.0-mm, 5.0 x 8.5-mm) were inserted in dummy bones. Implant stability as a function of peak insertion torque and resonance frequency values were recorded for each implant. RESULTS: 1. Bone quality was a major influential factor to achieve initial stability (P .05), however insertion torques were increased with wider and shorter implants (P < .05). 3. In D4 dummy bone, implant stability quotient values and insertion torques were decreased with wider and shorter implants (P <. 05). CONCLUSION: From a point of view of initial stability, it is suggested that use of wide and short implant may be helpful in avoiding bone augmentation procedures in area of adequate bone quality.