Titanium is a strong, lightweight, silver-gray metal that is found fairly commonly in igneous rocks and geological deposits. Titanium has a number of impressive properties, including the ability to bind with human bone in a process called biointegration or osseointegration. Because of this, and the fact that the body will not reject it, this metal can be used for a number of medical and dental purposes. Hip and knee replacements, for example, often involve the use of a titanium implant.
An additional advantage offered by titanium is that there are ways in which to treat the surface of a titanium implant so as to further encourage osseointegration. For example, giving the implant a roughened surface and treating it with a bioactive agent such as hydroxyapatite, will stimulate osseointegration and also increase the lifetime of the implant. This is of particular importance for younger patients, and also because older patients, as life expectancies increase.
The field of dentistry is increasingly finding use for titanium implants as well. A titanium implant for dental use will typically consist of a screw which resembles the root of a tooth and has either a smooth or roughened surface. The “root” is placed in the jawbone and the process of osseointegration is allowed to take place for several weeks or months. At the appropriate time, a dentist will then attach a crown to the root. Because the root is already integrated, the patient is then immediately able to use the new implant as if it were a natural tooth.
Titanium implants were successfully introduced by P.-I. Branemark and co-workers in 1969 for the rehabilitation of edentulous jaws. After 40 years of research and development, titanium is currently the most frequently used biomaterial in oral implantology, and titanium-based materials are often used to replace lost tissue in several parts of the body.
There are some alternatives to modulating the body's response after implant placement. Modifying the implant surface topography has been a successful path among the scientific community, with the primary goals of achieving faster bone contact to the implant surface and more predictable results after several years. Today, during the 86th General Session of the International Association for Dental Research, convening here, a team of Swedish researchers is reporting the results of experiments that focused on structures, so-called 'nanostructures', one million times smaller than a Canadian one-dollar coin. The results demonstrated enhanced bone response to dental implants modified with such small structures as soon as 4 weeks after implant placement.
Modifying the size and distribution of the nanostructures at the implant surface may not only represent a faster and more reliable treatment for patients, but also may help in understanding the sequence of events at the body-implant interface and provide guidelines for the further development of osseointegrated implant surfaces.
