Half the anxiety patients suffer in a dental office is created by the dentist himself," says Mardy Doyle. Those are uncommon words coming from a D.D.S., but Doyle is not the average tooth doctor. To start, his informality is disarming. Patients, including such luminaries as Joyce DeWitt of Three's Company and Natalie Wood, call him Mardy. He will sometimes wear the dentist's traditional white jacket, but prefers a shirt and tie instead. "The dental gown is an intimidating symbol," he explains. When patients enter Doyle's Century City, Calif. office, he doesn't say, "Sit down and open," but chats for a while before the work gets under way. His innovations are not just style. Recently Doyle perfected a new cosmetic technique called veneer capping which he calls "the most exciting thing that has happened in dentistry" since he began practicing nearly 35 years ago.

Doyle has applied veneer caps to hundreds of patients. Actor Denzel Washington Jr., who plays opposite George Segal (another Doyle fan) in the upcoming Carbon Copy, needed the caps to cover a gap between his front teeth. Another Doyle patient was a fledgling actress whose teeth had been stained as a child by the antibiotic tetracycline.

Veneer crowns were developed in 1973 at the University of Michigan School of Dentistry. They are made of acrylic no thicker than a fingernail and are cemented directly onto the front of a natural tooth. No anesthetic is required, nor does a healthy tooth have to be filed down to a spiky stump as with porcelain caps. Doyle believes veneers will last as long as porcelain caps (an average of six years), and decay cannot develop under them because they are sealed to the tooth.

There are other advantages. While conventional crowns cost from $300 to $800 each, veneer caps are one-third to one-half that. If need be, the entire procedure can be done in one sitting, though two are preferable. Doyle recently placed 14 caps in a woman's mouth during a three-hour session. With conventional caps, the patient would have spent at least nine hours in the chair.

During the first visit, Doyle makes plaster impressions of the patient's teeth. These serve as "patterns" for the veneers, which are custom-shaped. On the second visit, the translucent cap is painted on the underside to blend with the patient's other teeth. The veneer is then applied to the front surface of the tooth, extending one millimeter under the gum for a natural look, and just to the edge of the tooth. An ultraviolet curing light sets the adhesive. If necessary, the veneer can be ground off. Veneers are seldom used for molars, which require conventional caps to withstand the brunt of the chewing process.

Veneer capping has yet to win wide acceptance. Doyle estimates only about 10 percent of the dentists in Los Angeles use the method. One explanation comes from Kenneth Hochman, who teaches at the New York University College of Dentistry. "Veneers can be bulky, causing gum problems," he says. "They may discolor, chip and become dislodged more readily than porcelains."

Doyle offers another reason for this lack of enthusiasm. "It takes skill, training and an infinite amount of patience to learn this technique," he says. "It requires a lot of time to complete the procedure in one appointment. And there's a financial reason. There's more money in conventional crowns."

The 60-year-old Doyle was the son of an Oak Park, Ill. dentist. After graduating from Loyola University in Chicago, he entered the Navy Dental School in Bethesda, Md. He practiced on ships and naval bases for a dozen years, rising to the rank of commander before going into private practice in 1958.

Doyle lives in Malibu with his second wife, Maria, an amateur artist. He first heard about veneer caps while attending a 1977 seminar and began applying them in 1978. He has advanced the technique so that it now can be used for 20 of the 32 teeth in the mouth.

Doyle's approach to his craft, which he calls "humanistic" dentistry, has made an impression on his patients. Says actress DeWitt, "I was in my late 20s before I could get rid of the terror I felt toward dentists. Mardy's made that possible." Doyle has often heard such sentiments. "Too many dentists are trained to deal with the tooth rather than the patient," he says. "I believe in beautifying without terrifying."