Stability of loaded and unloaded implants with different surfaces.

Purpose: To compare the torsional strengths and the effects of functional loading on five different implant surface structures.

Materials And Methods: This in vivo longitudinal study of 9 months' duration examined osseointegration in 180 stepped cylindric implants placed into the mandibles of 18 healthy sheepdogs. Implants with five different surface structures were placed (n = 36 in each group): (1) smooth surface; (2) deep profile structure (DPS); (3) titanium plasma sprayed (TPS); (4) hydroxyapatite coated; and (5) sol-gel hydroxyapatite coated (SGHA).