SAN FRANCISCO -- More obvious than a sore thumb, an off-color tooth can mar the brightest smile. Yet whitening just one tooth -- without affecting its comrades -- presents so many challenges that dentists of the past have often counseled their patients to live with the problem.
Now three trends are converging to make whitening a single discolored tooth increasingly worth while, said John D. West, DDS, MSD, a Tacoma, Washington endodontist today at the American Dental Association's 148th Annual Session.
- New techniques have become available.
- Interdisciplinary teams are finding new ways to bring their skills to bear on the problem.
- People are living longer, so a bright smile is becoming a more worthwhile investment.
"We're going to live into our hundreds, and we're going to be socially and sexually active and we're going to have our teeth," said Dr. West.
From the standpoint of treatment, single discolored teeth fall into two broad categories: those with living pulp and those with dead pulp.
For the teeth with dead pulp, Dr. West described techniques of internal bleaching with "walking bleach." External bleaching with brushes works well also, he said, but it's time-consuming. So "who wants to do it?"
After cutting access for internal bleaching, the dentist fills the tooth with bleach. One of the chief problems with this approach, he said is reabsorption which occurs in about 6.9 percent of these teeth.
He attributed this problem to an anatomical characteristic found in about 8 percent of teeth: the enamel doesn't reach the cementum. "I call this the Bermuda Triangle of endodontics," he said.
As a solution, he recommended creating a barrier inside the crown, which should be molded by carefully measuring the shape of the epithelial attachment.
Afterwards, he advised, dentists should make a careful seal over the bleach. Dr. West recommended leaving the walking bleach in place for about six weeks.
Teeth with living pulps offer different options, he said. One common cause of discoloration in such teeth is calcification. In such teeth there are four possible solutions:
- A full crown or veneer
- Internal bleaching with endodontics
- Internal bleaching without endodontics
- External bleaching
Veneers are expensive and last only about 10 years, Dr. West said. Restoration, on the other hand, begins the restorative, periodontal cascade.
Endodontics can prevent further internal deterioration. On the other hand, cutting access for internal bleach may kill the pulp.
External bleaching is time-consuming and won't address the problems inside the tooth.
All these alternatives must be weighed carefully, Dr. West said.
Single-tooth treatments, he concluded, "may seem like a nickel-and-dime thing," but they can potentially bring great benefits to the patient.
