Prosthetic and biomechanical factors affecting bone remodeling around implants.

Bone remodeling and, consequently, soft tissue levels around osseointegrated implants may be influenced by many variables that are considered of prosthetic or biomechanical nature: implant-abutment connection type and geometry (external vs internal), timing of abutment connection (at uncovering vs delayed), abutment material (titanium vs gold vs ceramic), abutment shape and dimensions (convex versus concave, flush with the implant’s collar versus narrower), abutment surface topography (smooth vs microgrooved), number of abutment removals and reconnections (single vs multiple), type of prostheses retention (screw vs cement), loading modality (axial vs off axis, dynamic vs static), parafunctional habits (none vs clencher/bruxer). Many of these variables have been addressed in a previous EAED Closed Meeting by Happe and Körner.1 Therefore, this review will be focused only on the consequences of abutment or reconstruction micromovement on bone and soft tissue stability. Micromovements may occur whenever the abutment screw loosens, or when a prosthetic protocol that contemplates repeated connections and disconnections is selected. These situations may create mechanical irritation of the tissues and pumping of the fluids with bacterial toxins contained in the implant cavities. Thus, they may have negative repercussions on the stability of the peri-implant hard and soft tissues. The topics that will be investigated are: Implant-abutment connection geometry and its influence on screw stability. Abutment insertion protocol.