The next issue involves looking at the potential threats of titanium. Titanium is currently used in a wide range of fields. As such, there are many studies with regard to environment safety in the field and basic science. Such titanium is primarily used as titanium oxide nanoparticles. Animal experiments, especially in rodents, are being conducted to study the effects of titanium oxide nanoparticles on the human body. In these experiments, titanium was overdosed in rats and the distribution of titanium in the liver, spleen, bone marrow, lungs, brain, and kidneys and titanium-related problems were found in each tissue. In particular, lung problems, cytotoxic reactions, inflammation reactions, fibrosis, and tumors were observed. Current reports showed the possibility that particle accumulation and ions due to titanium corrosion could be a potential systemic risk. This could be seen in the report that abrasive particles of orthopedic prosthesis were observed in the bone marrow of other tissues. Additionally, there were concerns about the potential of these nanoparticles exhibiting neurotoxicity. There was a report that nanoparticles passed through the BBB, and studies of the effects of these particles on the CNS have been conducted. In the rat experiment mentioned above, titanium was observed to be distributed in the CNS, which was of necessary concern. Although the effects on the human body are not yet known, it is necessary to pay attention to the potential hazards as shown in the animal testing results.

Potential dangers from such an accumulation of titanium include yellow nail syndrome. We consider this as a possible side effect of titanium dental implants as well. In addition to this, it has been reported that patients with periodontal treatment medicines or processed foods coated with titanium, as well as implants, have developed symptoms of yellow nail syndrome. Titanium can accumulate in the body through various pathways, and implant erosion can be an additional pathway; therefore, dentists and other specialists also need to be concerned with these potential risks.