They are the releasing due to the friction between implant and bone surface during installation, the wear during debridement at maintenance visits, and the corrosion. Fretwurst et al. reported the metal particle in peri-implant soft tissue along with M1 macrophages and the increasing in titanium concentration with lymphocytes detection. In association with the metal particle releasing, the damage of implant surface during the installation procedure was also determined.

On the other hand, a study of Addison et al. using synchrotron X-ray microfocus spectroscopy in order to detect trace distribution of Ti in tissue demonstrated a scattered and heterogeneous distribution of Ti in inflamed tissues taken from around skin-penetrating Ti implants. The location and distribution characteristics of Ti particles suggested that debris from implant placement are unlikely to be the major contributors. The authors proposed that Ti in the tissue results can be derived from micro-motion and localized corrosion in surface crevices.

One of the causes of implant failure can be attributed to allergic reactions to titanium. There have been reports of hypersensitive reactions such as erythema, urticaria, eczema, swelling, pain, necrosis, and bone loss due to titanium dental implants. Despite of the limitation of the case report, these cannot be neglected. In several case reports in which titanium allergy was initially suspected, upon further investigations, the allergic agents were other metals. The reliability of the patch test for current titanium is not guaranteed for clinical use. Therefore, it seems that future studies and countermeasures are necessary.

The case for allergies after installation of titanium dental implants was recorded by Hosoki et al. at a 69-year-old male. The patient had the successful dental implantation in 2008. An allergic eczema reaction occurred in 2010 after inserting of a titanium screw due to a leg fracture. The titanium screw was removed a year later; however, the eczema was only reduced by 50%.