Implants are used for various ways in dentistry. One is prosthodontics, the field of dentistry that aims at provision of prosthetic replacement of missing teeth and oral tissue, is the major user specialty. They are also employed in various orthodontic treatments, such as temporary anchors within the jaw or palatal bone to support orthodontic devices and implements where suitable anchorage is not already available. Prosthodontic use involves permanent implantation within the jaw bones as a replacement of natural tooth roots, and also makes use of the natural process called ossoeintegration, which is the natural attachment of bone tissue to the implant material and growing around it. Titanium and its alloys have been shown to be the best materials for permitting integration of bone to the implant.
- Strength – A primary requirement of an implant is that it should be strong enough to support the prosthesis it is meant to hold. This means it must be anchored to a sufficiently strong body structure.
- Quality and Quantity of Jaw Bones – The shape and size of the implants depends on the bone structure to which the implant is to be made. If enough bone is not available in the jaw the implant may have to be made to the cheek bone. This will demand a longer size of the implant normally called Zygotic Implant. Properly selected and installed modern implants will give satisfactory service for over a decade.
- Safety – the material used for implant fabrication must be biocompatible, and must not generate any adverse or allergic reactions in its vicinity.
For replacement of an individual tooth first an abutment is attached to the implant which has already been drilled into its position. This is done with a screw. The crown (the prosthesis) is attached to the abutment in one of various ways. These may be use of cement or a suitably small screw. The crown may also be fused to the abutment during the process of manufacturing.
The same process can be used for a prosthesis involving multiple teeth, but normally a double implant anchored at two points will have to be used, although a cantilever arrangement may have to be made in special cases. The result can be a fixed or a removable prosthesis.
Bridges typically connect to more than one implant and may also connect to teeth as anchor points. A bridge supported by an implant (fixed denture) consists of one or more teeth attached to dental implants in such a manner that the prosthesis remains fixed at its position. The supported teeth will normally outnumber the anchor points. Those teeth which are directly over the implants are called as abutments. The in between teeth are called pontics. Bridges supported on implants have to be attached to implant abutments just as in the case of single tooth implant replacement.
Implant Supported Removable Dentures
An implant supported denture may also be made removable. It may also be called as implant supported over denture. The dental prosthesis is attached to the abutments in such a way that the user can safely and easily remove it and reinstall it. The abutment in this case has to be as a small button or ball (or some other suitable shape) which will mechanically mate securely with receptacles of corresponding shapes and inner sizes in the dental prosthesis.
Facial abnormalities may result from cancer treatment, or from injuries, or may be birth defects. To correct these facial prostheses can connect to implants installed in the cheek bone. Again, the facial implant may be designed for a fixed or removable prosthesis.
Orthodontic utilization of implants is for a limited period, or temporary. These implants are not as thick, and because of their function are called Temporary Implant Devices (TAD). They should be able to bear the force necessary for the desired tooth movement and reshaping. As implants do not have a periodontal ligament forces generated will not initiate any bone remodeling. Also their shorter duration of installation will not cause much osseointegration. Hence, removal will be easy when desired.
Be sure to check back for part 2 of our dental implant series where we’ll discuss the possible complications or risk factors in having implants put in.