Medicine: Engineering Dentures

An estimated 37 million Americans, just under a quarter of the population, wear false teeth (i.e., upper or lower plates, or both), and about 10 million more use partial dentures. For the great majority, regular removable plates are sufficient, but others find ordinary false teeth uncomfortable and irritating. For these “denture neurotics” one possible solution is a feat of tiny-scaled civil engineering known as the dental implant, i.e., fastening the denture to the jawbone to hold it in place permanently.

Dozens of implant techniques were tried over the years but most failed because the permanent denture either worked loose or irritated surrounding tissue. In recent years, dental surgeons hit on new methods that may solve the problem. Two basic types are now in use:

¶ The semiburied implant, using a Vitallium latticework placed on the mandible, or lower jaw. As the process is described in Implant Dentures (Lippincott; $12) by Drs. Aaron Gershkoff and Norman I. Goldberg of Tufts University School of Dental Medicine, soft tissues are sutured over the lattice, leaving four posts protruding in the mouth to support and anchor dentures.

¶ The completely buried implant, used by Dr. Stanley Behrman of Cornell University Medical College. The Behrman method, aided by modern physics, uses tiny (onequarter inch long) cobalt-platinum alloy magnets, the most powerful of their size ever developed. Inserted into the upper or lower jaw, the magnets attract other small magnets placed in the overlying denture to keep them in place. The mesh-covered magnets are strong enough to last the life of the denture-user.

To date, the semiburied method has shown better powers of retention, stability and chewing efficiency, but because chewing sets up great stresses and mandibles change shape over periods of time, the Vitallium lattice tends to become ill-fitting and protrude from the gums. The magnet implant stays in place longer, and observations over a five-year period show no loosening or irritation. Says Dr. Behrman confidently: “This is a technique with a future.”