Methods: In an in vitro trial, a 3D finite element model of a partial dentate mandible with designed DERPD and dental implants was established to analyze stress distribution in bone around terminal abutment teeth and implants with different lengths and angles.
Results: The stress in the PDL of first premolar teeth ranged between 0.133 MPa in 10 mm implants with the angle of 15 degree and 0.248 MPa in 7 mm implants with the angle of 0 degree. The minimum analyzed stress was specified to the implants with 10 mm length with the angle of 0 degree with the stress of 19.33 MPa and was maximized in 25.78 MPa for implants with 10 mm length with the angle of 15 degree. In implants with the fixed length of 7 mm, with the increase of transplanting angles, the stress on implants was gradually elevated. Similarly, in implants with the fixed length of 10 mm, increasing transplant angles resulted in quantize increase in the stress on implants.
Conclusions: With respect to minimizing stress on implants, not only the length and diameter of implant could be considered, but also the angle of implantation is concurrently necessary. Results showed vertical implanting resulted in lower stress on implant and therefore by increasing this angle, the distribution of stress could be gradually increased.