As a deputy mayor of Los Angeles, Tom Houston is accustomed to getting his picture taken frequently with celebrities, visiting dignitaries and other public officials.
But he had never been comfortable with the way he looked in those photographs. Yellowed teeth and a gap separating his upper front teeth, Houston said, made him feel self-conscious. "I developed a habit of smiling with my mouth closed," he confessed recently.
But no more. Houston, 40, is now smiling with his mouth open. The gap is gone, and his front teeth look brighter and shinier, their appearance improved by a technique called bonding. After his make-over, which lasted a few hours, Houston held a mirror to his face and said matter-of-factly: "I look a lot better."
Like Houston, many people born with less-than-perfect smiles are finding that bonding can help change their looks--and sometimes, they claim, even their outlook on life. In the past several years, cosmetic bonding has been done on about 6 million teeth, according to Dr. Frank Faunce, an associate professor of pediatric dentistry at Emory University School of Dentistry in Atlanta and a bonding expert.
Bonding is a general term used to describe a variety of techniques to attach materials to the tooth surface. It was introduced about 30 years ago after the development of an adhesive material used then to repair fractured teeth and to seal teeth and prevent decay.
As materials and techniques improved, cosmetic bonding was born. Today, it can be done directly or indirectly. In direct bonding, a technique that became widely available in the early 1980s, liquid plastic materials are placed on the tooth and shaped to the desired proportions. In indirect bonding, a procedure that has become available only in the last year or so, a preformed shell (veneer), usually made of porcelain, is bonded to the tooth's surface.
Both types of bonding can disguise a multitude of dental defects relatively quickly, proponents say. Bonding can help close gaps between teeth, repair chipped teeth and lengthen teeth to more pleasing proportions. It can also whiten teeth that have been stained by the antibiotic tetracycline or that have yellowed with age.
The techniques can sometimes take the place of more expensive and extensive procedures such as a crown (cap), and some adults opt for bonding in lieu of braces.
Bonding isn't a panacea, however, as even dentists who perform the procedure point out. "Bonding materials are not as color-stable as conventional crowns," said Dr. Sam Contino, a Pasadena dentist. The potential long-range side effects of bonding materials--considered foreign substances--are not yet known, he added, and a bonded tooth is not as strong as a crowned tooth.
The costs of bonding vary widely, as a survey of four Southern California dentists shows. Costs for direct bonding range from $75-$450 per tooth; for indirect bonding, $250-$500 per tooth. (Their costs for a crown, in comparison, ranges from $415-$600.) Typically, bonding is done on four to eight front teeth--the ones most noticeable when a person smiles--but sometimes patients choose to have additional teeth bonded. Dental insurance does not normally reimburse for cosmetic bonding.
In direct bonding, generally done in one appointment, the dentist prepares the tooth by roughening the enamel, the hard outer coating. A weak acidic solution is applied to the tooth's surface and is then washed off. "That's done,"Dr. Roger Lewis, a Beverly Hills dentist explained, "to create tiny pores on the tooth so the bonding material will stick."
Next, a liquid plastic bonding material, or resin, is applied to fill in the "pores" and achieve the initial bond. Then the dentist applies a thicker plastic material to the tooth and shapes it. When the desired shape is achieved, he uses an application wand with a special light to activate a catalyst within the plastic and harden it. Finally, the new tooth surface is polished.
Thin Shell Made
Indirect bonding generally requires two appointments. During the first, the dentist roughens the enamel and then takes an impression or mold of the teeth. The mold is sent to a dental laboratory to be used in making the veneer, a thin shell that resembles a false fingernail.
During the patient's next visit, the tooth surface is cleaned, a weak acidic solution is applied and then rinsed off, and a liquid plastic material applied. Finally, the veneer is positioned and hardened with the special light.
After a brief adjustment period, most patients don't notice the presence of the veneers. "They look and feel exactly like your own teeth," said Brenda Viereck of Van Nuys, who had indirect bonding done on four upper teeth.
Although dentists claim both procedures are virtually painless, most offer patients local anesthesia or nitrous oxide ("laughing gas").