Newer materials and techniques have greatly improved dental implants.

Dental implants replace teeth that have been knocked out or extracted because of decay or gum disease. They’re called implants because a crown — which resembles the visible part of a tooth — is fitted on top of a metal screw or peg that is "implanted" into the jawbone.

What to expect with dental implants

The entire process can take about four months and involve four or more appointments. The first step is an x-ray or CT scan of your jaw to see if there’s enough bone to hold an implant. CT scans are becoming the standard, although some experts think that an x-ray is just as good. At the next appointment, an oral surgeon or dentist will make an incision in the fleshy gum tissue that covers the jawbone, drill a hole in the bone, and put the implant in. Then he or she will stitch the gum tissue back over the implant. Local anesthesia should blunt the pain. This appointment may take several hours. You’ll then have to wait several months for the bone to mend and grow around the implant. Depending on the location of the tooth being replaced, you may be given a temporary false tooth to avoid an unsightly gap in your smile. Once the healing period is over, the gum is cut open again and a little metal cylinder called an abutment is put in the implant. It takes another few days for the gum to heal before the crown is put on, and you may need several more appointments to fit the crown properly.

Not surprisingly, there’s a lot of interest in speeding up this process. Some newer implants come already "loaded" with abutments and crowns, others with just the abutment. One advantage of the multistep approach, though, is that the bone can heal while there is no pressure on the implant.

Implant Implants are screwed right into the jaw and then capped with a crown. They can last 20 years. Bridge Bridges fit over teeth on either side of the tooth being replaced. About 30%–40% of the time there’s root canal work involved.

Complications and failures

If the drill hits and damages a nerve in your jaw, you’ll experience numbness, pain, or both. If the symptoms persist, it may be necessary to permanently deaden the nerve. But the complication rate of dental implants is very low, so this is unlikely.

If a dental implant becomes loose, dentists say it has "failed." But the problem is often subtle, so only a professional can detect it. Sometimes the dentist will just start over again with a thicker, longer implant. Failures are more common in the upper jaw, because it has less bone than the lower jaw. Oral surgeons can sometimes augment the jaw with a bone graft, to increase the chances for a successful implant.

Implant history: Gaining a toothhold Implants have been around for centuries; even the ancient Egyptians and Etruscans had crude versions. It is relatively easy to drill a hole in the jaw and put something in it. The hard part has been finding a material that will stay in. Ivory, gold, even children’s baby teeth — they were all tried. Then, in the 1950s, Per-Ingvar Branemark, a Swedish scientist, discovered quite by accident that bone healed tightly around titanium, a lightweight, corrosion-resistant metal. In the 1970s and 1980s, oral surgeons and dentists improved results further using low-speed drilling and "irrigating" with lots of water, which caused less damage to bone tissue so it healed better around the implant.

Who should do the implant?

Oral surgeons, periodontists (dentists who specialize in gum disease), prosthodontists (dentists who specialize in replacing teeth), and regular dentists all place implants. The credentials may not matter as much as the person’s experience. Ask how often he or she has placed implants. A regular dentist who has done many implants may be preferable to a specialist on a learning curve.

Your alternatives

If there’s tooth to work with, it can be crowned several times. Crowns — artificial teeth that fit over an existing tooth — are less expensive than implants and more likely to be covered by insurance. A bridge also costs less than an implant and is more likely to be covered. If the teeth around the missing one are in bad shape, a bridge is a good choice, because you’re fixing several problems at once. But usually a bridge doesn’t last as long as an implant (12–15 years vs. 15–20 years) and doesn’t feel quite as natural in the mouth.