A comparison of stress and strain distribution characteristics of two different rigid implant designs for distal-extension fixed prostheses.

: Stress and strain patterns around two rigid implant designs used as an abutment were compared and the displacement of natural teeth was investigated. The finite-element method was utilized to determine the stress and strain distributions. The results were evaluated in terms of the maximal tensile and compressive stress and strain in the bone around the abutment tooth and implants. The results indicated that the ITI 1 (hollow screw) implant led to high stress concentrations particularly in the apical region. The stress-transferring characteristics of ITI 2 (solid screw) implant were found to be more suitable than were those of ITI 1.