Titanium and titanium alloys, based on their excellent physicochemical properties and superior biocompatibility, appear to be suitable for medical devices. In addition to the original titanium properties, many functional enhancement such as shape-memory function, low elastic modulus, super-hydrophilic and antibacterial effect has been achieved by alloying and surface modification.
Titanium has been around since 1790 and gets it name from the Greek God “Titan”. Until the mid-1940s, 150 years since the discovery of the ore, it could not refining to create the “industrial” market. It is a new metal that has only 70-year history, compared to the iron (2000-3000 years ago). For decades titanium was considered an “aerospace metal” and was used exclusively in this application.
Beginning that Linkow has introduced a blade-type implants in the 1960s, resulted the widespread use of titanium implants in current dentistry. In the 1970s, Andreasen et al. found that the alloyed nickel and titanium exhibit shape memory and superelastic function. Nickel titanium wire is commonly used in orthodontic. Study of titanium began to increase in the dental materials science from the 1980s. Titanium casting in dentistry has now almost reached the stage to compete with dental casting using conventional base-metal alloys. Research efforts to overcome some problems associated with titanium casting, including the development of new titanium alloys suitable for dental use, have been continued.
On the other hand, the progress of the computer technology brings the innovation of the fabrication method, and dental CAD/CAM is developing from cutting process into the additive manufacturing technologies. It is still in the research stage to the fabrication of dental prosthesis by additive manufacturing of titanium and titanium alloys, but the application also is entering the field of view.
Titanium has enabled dental use with surrounding technological advances. Titanium is active metal originally and different from the noble metals such as gold alloy. It is found titanium can be easily corroded in the presence of an alkaline peroxide and the presence of an acid to form a complex ion such as hydrofluoric acid. Titanium and its alloys as viable options to more traditional noble and base metal alloys, but careful selection of processing methods and considering their characteristics are necessary to ensure success.
While reviewing the development of titanium and titanium alloys, I’d like to introduce the forefront of titanium research in dentistry.