Bioactive Ti Metal and its Alloys Prepared by Chemical Treatments: State-of-the-Art and Future Trends

Titanium metal and its alloys are widely used as various implants in orthopaedic and dental fields, because of their good biocompatibility and high mechanical strength. However, they do not bond to living bone. Here, we review the literature showing that they will spontaneously bond tightly to living bone, if they are treated with an acid or alkaline solution and then subjected to heat treatment. This occurs due to the materials becoming negatively or positively charged on their surfaces in the bodily environment, which induces apatite deposition. Porous Ti metal subjected to such treatment exhibits not only osteoconductivity but also osteoinductivity. Examples and clinical applications are reviewed. Titanium metal and its alloys spontaneously bond to living bone if they are soaked in an acid or alkaline solution and then subjected to a heat treatment. This is because they are charged negatively or positively on their surfaces in bodily environment, inducing apatite deposition (see image). These materials may find use as various kinds of implants in orthopedic and dental fields.