Types of Dental Implants
Since the initial introduction of titanium dental implants in 1965, dentists have tested a very wide variety of designs. Today, they are many types of dental implants from which to choose. Here’s a look at the major categories:
This implant is used to replace a single tooth or to place an implant-supported bridge for restoring more than one tooth. The implant is placed directly in the bone and works best for patients with moderate-to-good bone density. Subperiosteal implants (that replace missing jaw bone) and intramucosal inserts (to support dentures) are used for patients with more severe tooth loss and bone degeneration. We’ll just be looking at the endosteal implant today since that is the most commonly used variety.
Root Form Implants
Most dental implants are specifically designed to mimic the shape of a natural tooth root. Many implants in this category have features that encourage as much bone/implant contact as possible to ensure stability. The implant body may be screw shaped (threaded) or cylindrical. The surface can be smooth or roughly textured. Although some dental implants are solid, others are hollow or perforated with tiny holes.
Some implants are coated with a substance called hydroxyapatite (HA) to stimulate bone growth. HA is a calcium compound similar to calcium found in natural bone and is believed to speed the process of osseointegration through bio-integration. Dental implant researchers disagree on whether simply providing a more highly textured surface provides the same amount of benefit as using an HA coating. However, both approaches have an excellent success rate.
These rectangular dental implants are also called butterfly or plate form implants. They are flattened and substantially wider than a root form implant. Due to their elongated shape, blade implants are frequently used to support a bridge to replace multiple lost teeth. These implants are used when a patient has experienced some bone degeneration providing less space for a regular implant with a round circumference. They offer greater surface area for osseointegration. However, they may not be as strong as a cylindrical or screw shaped implant. Blade implants have a higher failure rate than root form implants. Since they are used in patients who are already experiencing bone loss (a major risk factor for implant failure), this is not necessarily because of a problem with the design.
Dental Implant Materials
Most dental implants are made of pure titanium which tends to be non-reactive in the body (not causing an inflammatory response). However, many modern types of dental implants are titanium alloys that include small amounts of metals such as vanadium, aluminum, tantalum, or niobium. The goal of using an alloy is to provide greater strength and stability to the implant – especially in thinner blade implants that may be prone to fracture. Ceramic implants are sometimes used in rare cases when a patient has an allergy to titanium. This material has osseointegration potential similar to titanium. However, the designs tried so far don’t seem to hold up to stress as well over the long term. Dentists are also exploring zirconium for its implant capabilities. This white metal offers an aesthetic result similar to a real tooth root with no grey metal shadow visible under the gum.
Screw vs. Cement Restoration
The type of dental implant used determines whether the crown or other prosthesis is attached using screws or adhesive. Originally, crowns were always added to the implant abutment with tiny screws. This method allowed dentists to make revisions later if needed. However, as the techniques for restoration improved, more restorations were cemented to the implant abutment. This approach is simpler and made the manufacture of implant components and restorations less complicated. Both screwed and cemented types are successfully used today.
Major Dental Implant Brands
Below are some of the largest, best known manufacturers of dental implants along with some popular brand names. The most established companies tend to have the longest running studies demonstrating the effectiveness of their products over time. However, this does not mean that newer implant designs offer poor results.
3i Implant Innovations (BIOMET 3i)
Bicon Dental Implants
SHORT®, NARROW, and MAX 2.5®
Nobel Biocare, Inc.
Brånemark Implant® and Steri-oss Implant®
The Straumann Company
You should speak with your dental specialist about his or her reasons for choosing a specific implant brand. The equipment and tools required to place each style of implant is slightly different. This means most prosthodontists and oral surgeons work primarily with only one or two brands of implants to meet different patients’ needs. Since proper placement of the implant plays a significant role in patient success rates, the expertise of the dentist is likely more important than the specific brand of implant he or she uses. Your dentist will select a specific implant for your treatment based on where it will be placed in your mouth, your bone density, and the type of restoration used to finish the implant.