Is the implant geometry affect the peri-implant bone loss?

Objectives: The aim of this study was to investigate the influence of implant geometry in peri-implant bone loss.
Methods: There were examined 183 patients treated with osseointegrated implants, performed at FUNDECTO (University of Sao Paulo - USP) from 1998 to 2012, rehabilitated with 916 implants in function for 1 year at least. The variable marginal bone loss was assessed according to the factor type of implant (cylindrical or conical shape and internal or external hexagonal connection).
Results: The t test for means of independent samples with unknown variance showed significant greater bone loss for cylindrical implants when considering the top of the implant as coronal reference point to measure bone loss. But, when the base of smooth neck was used as a coronal reference point for measuring the conical implants have significantly higher bone loss.
Conclusions: The implant geometry and the smooth neck length have significant influence on peri-implant bone loss. Tapered implants with microthreaded and shorter smooth neck showed better outcome on marginal bone loss.