Dental Implants


A dental implant is an artificial tooth root replacement and is used in prosthetic dentistry to support restorations that resemble a tooth or group of teeth. The most widely accepted and successful implant today is the osseointegrated implant. This forms a structural and functional connection between the living bone and the implant. A variation on the implant procedure is the implant-supported bridge, or implant-supported denture.

Procedure

A typical implant consists of a titanium screw (resembling a tooth root) with a roughened or smooth surface. An osteotomy or precision hole is carefully drilled into jawbone and the implant is installed in the hole.

Implant surgery is performed as an outpatient under general anesthesia (if several implants are to be placed) or with local anesthesia (for simple cases) by trained and certified clinicians including oral surgeons and periodontists. In straight forward cases patients can be implanted and restored in a single surgery, in a procedure labeled "Immediate Placement". In such cases a provisional or temporary prosthetic tooth or crown is shaped to the implant while it integrates with the bone.

A single implant procedure that involves an incision in the gum or gingiva (to expose the jawbone) takes about an hour, sometimes longer; multiple implants can be installed in a single surgical session lasting longer.

Healing and integration of the implant(s) with jawbone occurs over three to six months in a process called osseointegration. At the appropriate time, the restorative Dentist uses the implant(s) to anchor crowns or a bridge (a prosthetic restoration containing several crowns). Since the implants supporting the restoration are integrated, which means they are stable and strong, the patient is immediately able to chew normally.

In an immediate function procedure, the gum is usually not flapped. Instead, the surgeon removes a small plug of gum directly over the drilling site. The site is drilled and the implant is installed. Then a temporary crown is immediately added.

There are different approaches to place dental implants after tooth extraction. The approaches are:

According to the timing of loading of dental implants, the procedure of loading could be classified into:

After a few months the implant is uncovered in another surgical procedure by the doctor that placed the implant, usually under local anesthetic, and a healing abutment and temporary crown is placed onto the implant. This encourages the gum to grow in the right scalloped shape to approximate a natural tooth's gums and allows assessment of the final aesthetics of the restored tooth. Once this has occurred a permanent crown will be fabricated and placed on the implant.

An increasingly common strategy to preserve bone and reduce treatment times includes the placement of a dental implant into a recent extraction site. In addition, immediate loading is becoming more common as success rates for this procedure are now acceptable. This can cut months off the treatment time and in some cases a prosthetic tooth can be attached to the implants at the same time as the surgery to place the dental implants.

Considerations

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.

In all cases, what must be addressed is the functional aspect of the final implant restoration. How much force per area is being placed on the bone and implant interface? Implant loads from chewing can exceed the of the implant bone interface and/or the titanium material itself, causing failure.

The dentist 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. The restoring dentist may consult with the periodontist, endodontist, oral surgeon to co-treat the patient.