Dental Implants

A dental implant is a titanium “root” device used in dentistry to support restorations that resemble a tooth or group of teeth to replace missing teeth. Virtually all dental implants placed today are root-form endosseous implants, i.e., they appear similar to an actual tooth root (and thus possess a “root-form”) and are placed within the bone (end- being the Greek prefix for “in” and osseous referring to “bone”). The bone of the jaw accepts and osseointegrates with the titanium post. The osseointegration is the component of this implant procedure that makes it resemble the look and feel of a natural tooth.

Prior to the advent of root-form endosseous implants, most implants were either blade endosseous implants, in that the shape of the metal piece placed within the bone resembled a flat blade, or subperiosteal implants, in which a framework was constructed to lie upon and was attached with screws to the exposed bone of the jaws.

Dental implants can be used to support a number of dental prostheses, including crowns, implant-supported bridges or dentures. They can also be used as anchorage for orthodontic tooth movement. The use of dental implants permits unidirectional tooth movement without reciprocal action.

The routine use of dental implants has revolutionized prosthodontics and the way missing teeth are replaced. Dental implants have become the standard of care for the replacement of teeth because dental implants allow a missing tooth (or teeth) to be restored to optimum function and appearance without invading or damaging any other teeth or tissues. 

In the past a patient missing a single tooth would often receive a fixed bridge where the teeth on either side of the space are prepared for crowns and a false tooth suspended between them. With today’s technology the patient is ideally treated by a crown supported by a dental implant, avoiding any compromise to the other teeth. Dental implants are the ultimate solution for young people with congenitally missing teeth such as lateral incisors.

Dental implants can also replace multiple missing teeth which are traditionally replaced by a removable partial denture. Occasionally dental implants can act as anchors for a fixed bridge to replace the teeth making the removable partial denture obsolete. In some cases there are too many teeth missing to use a fixed bridge; however, using a dental implant with an attachment that snaps into the removable partial denture will significantly improve its stability and improve the patient’s chewing function.

Perhaps the best known use of dental implants is treating patients without any teeth. Denture wearers often suffer due to loose and “floating” dentures, and dental implants offer many benefits to patients without teeth. Stability of the dentures is improved with the use of even two dental implants with attachments, but greater satisfaction is achieved as the number of dental implants is increased. Depending on the number of dental implants utilized to replace the teeth a denture can be made that clips onto a bar supported by the dental implants or a fixed denture that remains in the mouth can be attached to the dental implants. Dental implants also can help preserve the patient’s jaw bone and retard the shrinking of the jaw that is routinely seen in long-term denture wearers. 

Talk to a prosthodontist today about using dental implants to increase your confidence and improve your smile.

Considerations during treatment planning

For dental implant procedure to work, there must be enough bone in the jaw, and the bone has to be strong enough to hold and support the implant. If there is not enough bone, more may need to be added with a bone graft procedure discussed earlier. Sometimes, this procedure is called bone augmentation.

In all cases careful consideration must be given to the final functional aspects of the restoration, such as assessing the forces which will be placed on the implant. Implant loading from chewing and parafunction (abnormal grinding or clenching habits) can exceed the biomechanic tolerance of the implant bone interface and/or the titanium material itself, causing failure. This can be failure of the implant itself (fracture) or bone loss, a “melting” or resorption of the surrounding bone.

The prosthodontist must first determine what type of prosthesis will be fabricated. Only then can the specific implant requirements including number, length, diameter, and thread pattern be determined. In other words, the case must be reverse engineered by the restoring dentist prior to the surgery. If bone volume or density is inadequate, a bone graft procedure must be considered first. The prosthodontist may consult with the oral surgeon, periodontist, endodontist, or another trained general dentist to co-treat the patient. Usually, physical models or impressions of the patient’s jawbones and teeth are made, and are used as physical aids to treatment planning. Advanced computer-assisted tomography or a cone beam CT scan can also be used to achieve the proper treatment plan.

Computer simulation software based on CT scan data allows virtual implant surgical placement based on a barium impregnated prototype of the final prosthesis. This predicts vital anatomy, bone quality, implant characteristics, the need for bone grafting, and maximizing the implant bone surface area for the treatment case creating a high level of predictability. Computer CAD/CAM milled or stereolithography based drill guides can be developed for the implant surgeon to facilitate proper implant placement based on the final prosthesis’ occlusion and aesthetics.

Success rates for Dental Implants

Dental implant success is related to operator skill, quality and quantity of the bone available at the site, and the patient’s oral hygiene. The consensus is that implants carry a success rate of around 95%.

Contributing factors to the success of dental implant placement, as with most surgical procedures, include the patient’s overall general health and compliance with post-surgical care.

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