Teeth smart enough to repair themselves
If teeth were able to fix themselves, those painful Novocain shots and that awful drilling would be things of the past.
It could happen. Dental researchers have created an experimental material they say will stimulate repair of defective teeth, preventing decay and eventually making fillings obsolete.
“These ingenious ‘smart’ materials could lower the number of cavities significantly,” says Dr. Frederick Eichmiller, director of the Paffenbarger Research Center of the American Dental Assn. Health Foundation in Gaithersburg, Md. The research center, in collaboration with the National Institute of Standards and Technology, has devised many of the tools that have revolutionized dentistry. “This will be the next step beyond fluoride,” he says.
Fluoride works by strengthening the tooth structure, which makes it more resistant to decay. The new material, a composite of calcium and phosphate (the essential building blocks of teeth), mimics the teeth’s natural repair mechanism.
Under normal conditions, teeth dissolve and rebuild themselves, says Eichmiller, “like any other living tissue. When this process is in balance, there are no problems. But when teeth are dissolving faster than they can be rebuilt, that’s when a tooth decays.”
Typically, teeth decay because bacteria on their surface convert the sugar in foods to lactic acids, eroding the calcium in tooth enamel. Saliva, which is rich in calcium and phosphate, can restore or repair the weakened enamel. But if the bacteria are not removed frequently, the acid eventually destroys the softer dentin underneath the enamel, creating a cavity. The new material, which can be used in dental filling materials and adhesives, tips the balance back toward reconstruction.
“The saliva penetrates this composite, and transports the calcium and phosphate ions to the surrounding tooth environment,” says Joseph M. Antonucci, a chemist at the National Institute of Standards and Technology who helped formulate the material.
The new substance has several potential uses. The first is as an adhesive cement under orthodontic brackets, which “is an area that is very prone to decay because it’s hard to clean,” Antonucci says. It also could be used to turbo charge the plastic sealants used to coat children’s teeth, and as a liner underneath conventional cavity fillers, to extend the life of fillings and prevent further decay.
The repair technology is being tested in a pilot study of 30 patients with braces, and several companies have expressed interest in using the compound commercially. Scientists hope these smart materials will become a routine part of dental practice within the next few years. “There’s definitely a big need,” says Eichmiller, “especially for people with bad teeth.”
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Beyond the drill
A new cavity-preventing substance is just one of many pioneering dental technologies that have resulted from the 75-year collaboration between the American Dental Assn.’s Paffenbarger Research Center and the National Institute of Standards and Technology, a government research laboratory managed by the Department of Commerce.
The scientists involved have helped devise the modern high-speed dental drill, protective tooth sealants, orthodontic bracket bonding materials, tooth-colored filling materials, stronger adhesives, and even those ubiquitous hand-held mirrors.
The dental industry “is fairly small,” says Dr. Frederick Eichmiller, “and the majority of manufacturers can’t afford an internal research and development program. So they license the technology that we develop.”
