Dental Implants: When and How They Are Used

As a prerequisite to placing a dental implant, there must be sufficient bone in the placement site. In situations where the patient’s remaining bone in the implant site is inadequate, either artificial or cadaver bone may be added. However, each case is unique and must be properly evaluated clinically and radiographically before treatment. Despite many patients’ misconceptions, dental implant placement usually results in minimal discomfort. This is because the implant site has no nerve innervation and consequently little or no resulting pain.

A conscientious dentist always tries to save teeth when the probability of treatment success is reasonable, but there are times when treatment would be an imprudent and costly decision rendering poor results, so an implant is often used to replace a tooth. Following are six instances when the option of replacing a missing tooth with a dental implant should be considered:

1. A tooth may have advanced periodontal disease and presents with a poor prognosis and should be extracted and replaced.
2. A tooth may have extensive decay below the bone level and cannot be restored and must be extracted.
3. A tooth may have been previously treated with endodontic (root canal) therapy that has failed and there is a poor prognosis for retreatment success of the root canal.
4. The individual may have a space due to a congenitally missing tooth or a previous extraction.
5. A tooth may appear to be a candidate for root canal therapy due to extreme decay, but upon radiographic review the prognosis is extremely low for success.
6. A tooth is fractured or broken to an extent where restoration is not feasible or possible.

After the implant has been placed and osseointegration has occurred, an abutment—which is a metal attachment—is placed into the implant. At that point, an impression is taken of the abutment and sent to the dental laboratory. The laboratory technician then fabricates a crown and sends it back to the dentist’s office. At this stage, the patient returns and the crown is cemented onto the abutment, completing the procedure of replacing the missing tooth.

Dental implants can also be used when there is an area in the mouth where multiple teeth in a row are missing. The option does exist to replace each tooth individually with an implant; however, when cost is a consideration, it is less expensive to place a fixed implant-supported bridge. For example, if three teeth are missing, one implant is placed in the location of the missing tooth next to the remaining natural tooth. The second implant is placed where the third tooth is missing. When both of the implants have undergone osseointegration, abutments are placed in each implant, and an impression is taken and sent to the dental lab, where a three-unit implant bridge is fabricated. It is then returned to the dentist and is permanently cemented onto the abutments. The resulting appearance is natural and when done properly, it is virtually impossible to detect that any teeth were missing.

When a patient is missing all of their teeth in one or both arches, dental technology has enabled us to replace teeth without the “old fashioned” traditional denture that has been used for centuries. Without implants, on the maxillary (upper) arch, the hard palate is completely covered by the denture’s acrylic base and taste is severely compromised. In addition, despite the amount of gingiva (gums) and the existing underlying bone support for the dentures, retention varies depending on the patient’s actual bone formation and the amount of existing bone. Consequently, despite the dentist’s best efforts and utilizing the finest impression techniques, the patient may still need to resort to using denture adhesives to enhance retention of their dentures. Many patients find their end results very disappointing. Fortunately, with the advancement of dental implants, these problems have been virtually eliminated.

There are two excellent options, utilizing different types of implants, to replace a full arch of teeth. The need for covering the palate is eliminated and the extent of the acrylic denture border is minimized, thereby greatly increasing patient comfort. With implants, the support of the prosthesis is no longer dependent upon the patient’s ridges and bone, but is transferred to the implants.

The first technique utilizes a removable overdenture, which locks into the supporting implants and stays firmly in place. It stays in the patient’s mouth the entire day and evening and is removed only for a brief period while brushing the implants and prosthetic teeth at bedtime. It is then placed back in the mouth until the following day when the process is repeated.

The second technique, “All-on-4”, is a fixed prosthesis which is screwed into the underlying implants which are placed with varying angulation. This technique utilizes a different type of implant than the removable procedure. The advantage of the All-on-4 technique is that the prosthesis is permanently screwed into the supporting implants and is only removed periodically (recommended every six months) for a routine cleaning. It is the most stable way to replace a full arch of missing teeth, with the exception of replacing each tooth with an individual implant. The All-on-4 technique allows for the greatest stability and results in the closest simulation of having your own teeth.

Both techniques can be performed in one day. The patient arrives at the office, has all the teeth removed and implants immediately placed, and leaves with the prosthesis in place that same day—and with a beautiful smile. Many patients report that after treatment, the discomfort is minimal and they have little difficulty adapting to their new teeth.