Many of titanium’s physical and mechanical properties make it desirable as a material for implants and prosthesis. The strength and rigidity of titanium is comparable to those of other noble or high noble alloys commonly used in dentistry, and titanium’s ductility, when chemically pure, is similar to that of many dental alloys. Titanium can also be alloyed with other metals, such as aluminum, vanadium or iron to modify its mechanical properties.
The low density of titanium provides for high-strength, lightweight prosthesis. Additionally, dental porcelain can be fused and bonded to titanium to produce an aesthetic, lifelike restoration.
Titanium has been used in cast dental prosthesis since the 1970s. Equipment is available to cast titanium into single-and multiple-unit-crown-and-bridge frameworks, implant-supported structures and partial or full denture bases.
For more than 25 years, titanium has been used for both endosseous and subperiosteal implants. Endosseous implants have taken the form of rods, posts and blades made of either pure titanium or titanium alloys. The oxide layer on the implant surface permits close apposition of physiological fluids, proteins, and hard and soft tissues to the metal surface. This process, whereby living tissue and an implant become structurally and functionally connected, is called osseointegration. Titanium also has been used successfully as a bio compatible implant material, and continual improvements in both device design and clinical implantation techniques have led to well-accepted and predictable procedures.
In 1996, the ADA’s Council on Scientific Affairs updated its position regarding the use of endosseous implants as a treatment modality for full or partially edentulous patients. In this 1996 update, the Council stated that ADA-Accepted endosseous implants, including those made of pure titanium or titanium alloys, can be used only to treat carefully selected patients with whom the relative merits of benefit and risk have been fully discussed. Before the 1996 update, the Council had not recommended endosseous implants for routine clinical practice. Nevertheless, the Council’s report indicated that many factors must be considered when deciding whether to use endosseous implants as a treatment option, and that some of these factors required further study. Some of the factors identified by the Council included the use of single-tooth implants, new methods of retaining prosthesis, effects of various surface treatments and coatings on titanium and titanium alloys, and oral hygiene issues. If endosseous implants are to be placed, however, titanium and titanium alloys are recommended due to their bio compatibility and clinical success.