Goodbye Dentures !

Goodbye, Dentures: Improved Dental Implants Gaining Favor

By JULIE BAIN

Carol Cotter vividly remembers the time when, as a squeamish 14-year-old, she had to help her grandmother put in her false teeth.  "I thought, `I don't ever want that to happen to me,' " said Ms. Cotter, 58, a social worker in Marlboro, N.J.  But by the time Ms. Cotter was in her mid- 30's, she had already lost several teeth.  "Then, over the years, I developed periodontal disease, and my teeth began to loosen and shift, and I was just a mess," she said.

Now, she is confident that she will never have to resort to dentures. Four years ago, she had all her upper teeth and several lower ones replaced with dental implants. The implants look and feel natural, she said, and she can eat anything she likes. All in all, she is thrilled with the results.

A dental implant is an artificial tooth made of metal with a porcelain coating designed to make it look real. Its most important component is its root, a titanium screw anchor that is surgically implanted into the jawbone, usually by an oral surgeon or periodontal surgeon. Patients usually need just local anesthesia.

Initially, the anchor is implanted alone, without the tooth. Gradually, during a healing period that can take several months, the bone grows around the implant, securing it. Then a replacement tooth, or crown, is attached to the metal post. Implants can also be used to anchor bridges and permanent dentures when more than one tooth is missing.

As with any surgery, the main risk is infection, though it is not common.

Ms. Cotter said the implant surgery was less arduous than she expected. "Having the teeth removed years before was so much more traumatic than having the implants," she said. "I was really frightened, but it was nothing. I would much rather have the implant procedure done than have root canal or an extraction."

Many Americans lose their teeth, mainly because of cavities and periodontal disease. According to the Centers for Disease Control and Prevention, by age 17, 7 percent of people in the United States have lost at least one permanent tooth because of decay.

Among adults from 35 to 44 years old, 69 percent have lost at least one permanent tooth. By age 50, Americans have lost an average of 12 teeth (including wisdom teeth). And among adults 65 to 74, 26 percent have lost all their teeth.

The number of implant procedures has tripled in the last 10 years, according to the American Dental Association. About two million implants are done each year. As the materials and techniques have improved, so have success rates.

"Implant dentistry today has among the highest success rates of any medical procedure," said Dr. Michael R. Wiland, who has practiced restorative dentistry in New York for 35 years and implant dentistry for 15 years. He is also co-author of a recent book about implants, "Smile: How Dental Implants Can Transform Your Life."

Dr. Martha Somerman, associate dean for research at the University of Michigan School of Dentistry, and president of the American Association for Dental Research, said: "Implants are much better designed than they used to be. Individual implants today are quite successful. However, the success depends on the integrity of the patient's own bone, and the ability to build new bone if needed."

Success rates of screw-type implants vary, depending on where in the jaw the implants are placed, ranging from about 96 percent in simple individual implants with good bone structure underneath, to about 85 percent in some cases where bone grafts are needed. A successful implant is defined as one that lasts 10 years or more. Many last a lifetime, Dr. Wiland said.

"And frequently, the failed ones can be replaced or repaired," he added. "It doesn't mean the case is not successful."

Still, implants are not for everyone. Patients' health and medical history may preclude them from being good candidates for implants, especially if they have bone loss, diabetes or certain cardiac problems.

But, said Dr. Babak R. Ghalili, a New York periodontal surgeon who specializes in difficult cases, "there are so many modalities now in bone grafting and implant technology that you can find a solution for nearly every patient" who has a suitable medical history and is motivated to take care of the implant so plaque does not form and cause bone loss.

Implants have come a long way since their early history. The first implant, said Dr. Wiland, was found to be a copper peg hammered into the upper jawbone of an Egyptian king about 3,000 years ago.

"But this may have been done by the undertaker to improve his smile in the underworld," Dr. Wiland said.

Researchers have found that about 1,000 years later, in what is now Honduras, people tried to replace their lost teeth with animal ones, or with teeth purchased from slaves and the poor. But throughout most of history, false teeth proved easier and less painful than such experimental transplants.

Dentists in the United States began experimenting with devices called blade implants in the 1950's and early 60's. They sat in a trough of bone and were held in by fibrous tissue. But the bone did not grow in around around the blade.

Dr. Wiland said: "I tried them and stopped doing them because they were 50 or maybe 60 percent successful, and when they weren't, they caused damage. So the discipline sort of stagnated for a while."

Then, in the mid-60's, Dr. Per-Ingvar Branemark, a professor at the Institute for Applied Biotechnology at the University of Goteborg, Sweden, discovered that titanium would fuse to bone. He created methods and materials that have been used as models for implants for more than 30 years.

At first, the implants were placed only in the front part of the lower jaws where no nerves were involved. The technology evolved in America, and in the early 80's dentists began putting implants in the back of both the upper and lower jaws, where the bone is less dense than in the front and the anatomy is harder to work with.

The next step was to restore bone where it had deteriorated because of tooth loss or gum disease. Further advances are being made in bone grafting, making implants possible for people who would have been considered untreatable just a few years ago.

Dr. Harold Slavkin, dean of the dental school at the University of Southern California and former director of the National Institute of Dental and Craniofacial Research, said, "The superb and meticulous research provided by Dr. Branemark and his colleagues and many other clinical scientists over the past 50 years has provided a rationale and a solid foundation for dental implants."

Materials and techniques are still evolving. For example, although screw fixtures have not changed much in structure recently, they are now coated with different substances that increase the surface area to which the bone can adhere. Dr. Wiland said implant companies had also engineered better ways to attach the teeth to make them stronger and better looking.

Another improvement is in the timing of the procedure. Traditionally, implants took three to six months for the bone to fill in around the titanium post before the crown could be put on over the surface. But with new techniques, Dr. Ghalili said: "You can put implants in and put the teeth on them in two or three weeks. However, you have to be a good candidate for those techniques."

A good candidate would be someone with healthy gums and enough bone to hold the implant.

Dr. Slavkin cautioned that, despite all the advances, "a well-educated and well- trained clinician is imperative."

Dr. Ghalili agreed, and said: "Implants are really great. They help a lot of people, but they have limitations and require expertise from whoever is doing them. That's key in their success. But it's very lucrative, so everybody wants to do implants."

He said he advised people considering implants to talk to others who had them.

"Come to me and ask for the names of five patients who have had implants so you can talk to them and see what their experience was like," Dr. Ghalili said. "People seem reluctant to do that, but they should."

Ms. Cotter said that although she was pleased with her implants, she wished they were less expensive. The cost varies widely, from about $2,500 for a simple individual implant to tens of thousands of dollars for full reconstruction. Some dental insurance plans cover part of the cost, but in many cases, the coverage may be only a small percentage, or none at all.

Dr. Somerman said: "As it becomes a more routine procedure, the prices of implants are going to come down because of the demand and the competition. On the other hand, implants are sometimes cheaper than putting a bridge on that same area."

Dr. Slavkin said that someday, implants might become obsolete. "Bioengineered tooth replacement using stem cells from the individual who will receive the implant is on the horizon," he said. "Through continued public and private sector investments into research, we may see a prototype within the next decade."