Foreign Bodies in Proximity to Failing Dental Implants

Introduction: Recent studies suggest the potential role that foreign bodies play in the pathogenesis of implant failure. The aims of this investigation are: (1) to evaluate the presence of foreign bodies in proximity to failing dental implants that have been removed; (2) to examine the effect that these foreign bodies have on the surrounding hard and soft tissues. Materials and Methods: A total of 21 patients possessing 34 dental implants were enrolled in this prospective, cross-sectional ex vivo study. Five of these 34 implants were removed for restorative reasons and were used as positive controls. A total of 6 implants (5 failed, 1 control) were assigned to group E (enzymatic digestion) and 28 implants (23 failed, 5 control) were assigned to group GS (ground section). Group E implants underwent enzymatic digestion in collagenase/dispase. Foreign bodies were isolated and imaged using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). Group GS implants were ground to 100 µm thick sections. Specimens were imaged using light microscopy, SEM, and EDS. Results: One patient dropped out prior to implant removal, resulting in 33 total implants. Group E specimens primarily contained organic elements and minerals (carbon, oxygen, nitrogen, calcium, phosphorus, sodium, and chloride). Zinc was found in select specimens. Light microscopy of group GS revealed a greater number and size of titanium particles associated with failed implants. Titanium particles were commonly observed in proximity to soft tissue, demineralized bone, and inflammatory cells. Failed implants displayed surface delamination and bacterial colonies with accompanying titanium particles. Titanium particles were observed near the lumen of intrabony blood vessels in both failed and control implants. SEM and EDS of failed implants revealed countless titanium particles exfoliated from the implant surface. EDS of positive controls revealed the presence of titanium within the bone-implant interface. Conclusion: A greater number and size of titanium particles are associated with failed implants when compared to controls. Titanium particles are correlated with bacteria, inflammation, implant surface delamination, and local vasculature. Implant surface distortion and titanium exfoliation may produce an environment that is not compatible with health