Titanium is one of the most widely used materials for dental implants due to its mechanical strength, biocompatibility, and a long history of use. Current titanium dental implants possess a high success rate; however, failures are still being reported. Cause of these implant failures can be poor oral hygiene, uncontrolled deposition of plaque, and calculus around the implant which cause peri-implantitis or occlusal problems. In the light of new investigations in biological and mechanical aspects, the allergy response to dental implant materials and toxicity of the particle released from implant system are reported to have a role in implant failure. There are also a variety studies on titanium and its alloys as well as implant surface treatment materials to determine their toxicity behavior and its mechanism. Typical examples include bone loss due to inflammation reactions due to implant corrosion, hypersensitivity to titanium and allergic reactions, and yellow nail syndrome.

Titanium is also used commonly in industrial applications such as coatings for pharmaceuticals, processing materials for gum and confections, food additives, and paints. In the medical field, titanium and titanium alloys have been used to fabricate various of implantation and fixation systems. With the widespread use of titanium, there are concerns regarding the adverse effects of titanium accumulation and its effects on the human body. Therefore, stability and potential hazards of titanium should also be evaluated and discussed.

The purpose of this article is to provide a general overview of the stability and risk associated with titanium materials and to suggest alternative solutions. We examined the toxicity of titanium through a division into four categories: the toxicity of titanium, the toxicity of titanium alloys, the toxicity of titanium implants, and diseases related to titanium.