Effects of lateral cortical anchorage on the primary stability of implants subjected to controlled loads: an in vitro study

Our aim was to evaluate the effects of lateral cortical anchorage on the primary stability of implants subjected to immediate loading. Implants were placed into bovine bones with monocortical anchorage (implant placed through the cortical bone of the crest) and bicortical anchorage (the crest cortical bone plus one cortical bone on the lateral side). Loads of 25 N and 50 N were applied to the implants in different cycles. The implant stability quotient (ISQ) was measured before and after the cyclic loadings. Under 25 N load there was no difference in ISQ between 1800 cyclic loading and preloading, but the values decreased significantly after 3600 cyclic loading in both groups (p < 0.05). Under a 50 N load the ISQ value after 1800 and 3600 cyclic loading decreased in the monocortical group (p < 0.05), but there was no difference between 1800 cyclic loading and preloading in the bicortical group, and the ISQ in the bicortical group was higher than in the monocortical group after 1800 cyclic loading (p < 0.05). Our results suggest that the stability of implants with bicortical anchorage decreased more slowly under higher loads.