Impact of abutment microstructure and insertion depth on crestal bone changes at nonsubmerged titanium implants with platform switch

ObjectivesTo assess the impact of microgrooved abutments and the insertion depth on crestal bone changes at titanium implants with platform switch. Materials and MethodsA total of n=3 titanium implants (conical abutment connection) were inserted in each hemimandible of n=6 foxhounds with the implant shoulder (IS) located at either epicrestal, supracrestal (+1mm), or subcrestal (-1mm) positions and randomly (split-mouth design) connected with machined or partially microgrooved healing abutments. At 20weeks, tissue biopsies were processed for histological (primary outcome: net bone loss - NET) analyses. ResultsSubcrestal positioning of IS tended to be associated with higher mean NET values (mm) at both machined (subcrestal [-0.720.32] > epicrestal [-0.34 +/- 0.21] > supracrestal [+0.20 +/- 0.64]) and microgrooved (subcrestal [-0.48 +/- 0.25] > epicrestal [-0.13 +/- 0.54] > supracrestal [+0.33 +/- 0.58]) abutments. However, these differences failed to reach statistical significance. ConclusionsThe insertion depth may have a direct influence on crestal bone-level changes at both types of abutments investigated.