Clinical trials, outreach—
changing the face of dentistry
Vincent A. Segreto, DDS, professor of dental diagnostic science, has changed the face of dentistry in this country and in the tiny Central American country of Guatemala.
Every year, thousands of people participate in his research studies at the Health Science Center, with some involving as many as 1,200 participants. His creative work has led to:
- an experimental stannous fluoride dental paste that proved to be an excellent agent in reducing dental decay;
- toxicity studies on stannous fluoride to ensure safety for patients;
- development of a stain resistant, less soluble, dental restorative material for anterior teeth;
- and initiation of studies on mercury fillings—the research resulted in warnings to the dental profession about the hazards of mercury.
With Edwin M. Collins, DDS, professor of dental diagnostic science, and in cooperation with the U.S. Environmental Protection Agency, the Texas Education Agency and the Texas Department of Health, Dr. Segreto conducted a three-year study to identify significant changes in teeth caused by drinking water containing natural fluorides. Specifically, the study focused on socially unacceptable mottled enamel and discoloration of teeth.
Dr. Segreto spent part of his early career in the U.S. Air Force, where he was chief of dental research. For his outstanding service to the military, he was given the Legion of Merit and the Recognition of Outstanding Qualifications in General Dentistry, the highest level of professional achievement recognized by the Air Force.
In 1975 he was recruited by Charles R. Morris, DDS, then head of the department of dental diagnostic science, to conduct privately sponsored dental research for the Health Science Center. Stephen R. Matteson, DDS, current chairman of dental diagnostic science, joined the university in 1988.
"The most difficult job we’ve had throughout the years has been, and still is, finding subjects for our research studies," Dr. Segreto said. "We recruit people by telephone, flyers and radio ads and we still spend much of our time trying to find qualified persons to participate in our studies."
Dr. Segreto’s research efforts extend to Guatemala, where villagers walk long distances, sometimes for hours, to receive health care from him or one of his research team members. His research group includes several Guatemalan dentists and a Guatemalan physician, who trained a midwife and other local health professionals. The group travels to the country’s remote, mountainous interior to perform physicals, extractions and other basic medical and dental care.
"While serving in the Air Force as chief of dental research, one of my young officers was part of a professional group that traveled to a remote area of Guatemala to perform various volunteer health services," Dr. Segreto explained. "He found definitive dentistry was impossible since decay had destroyed the crowns of the molar teeth in most of the population. Extraction was the only treatment possible. However, when the team was doing the procedure they had tremendous difficulty removing the tooth roots, because of the density of the bone surrounding the roots.
"At the time, the ongoing theory of periodontal disease belied this occurrence. The seeming contradiction of current beliefs led to our first project in Guatemala," Dr. Segreto added. "Our findings were conclusive only to the extent that their diet is very high in calcium. This results from soaking corn in a limestone solution called ‘kai.’
"I was not satisfied with some of our clinical findings, so—if I live long enough—I will return to repeat this study," Dr. Segreto stated.
"All of our ongoing work in Guatemala is quite important," Dr. Segreto said. "The first two studies were sponsored by the Health Science Center, but now an agreement has been developed between our university and the Universidad de Mariano Galvez of Guatemala City, where I have an adjunct faculty appointment.
"Through the efforts of Wayne P. Pierson, PhD, director of the Institutional Review Board (IRB), Angie Khan, institutional coordinator, research review, and other staff members at the Health Science Center," Dr. Segreto noted, "an institutional review board has been established in Guatemala, so they can now do their own studies."
The Health Science Center has provided much of the needed equipment, supplies and building modifications in Guatemala to aid both rural and urban clinics. Clinical trials are conducted in remote areas under less than ideal conditions, and Guatemala City now hosts a fully functioning research clinic with six operatories.
"The enduring contribution to the host country, however," said Dr. Segreto, "is in the professional education for local dentists. Several promising young professionals have been trained in research procedures as examiners, and in other aspects of a grant-funded environment."
Dr. Segreto added that no complex project can succeed without cooperation from many persons. "Special kudos go to my team," Dr. Segreto said. "The easiest job in the world is to supervise talented, dedicated people—so industrious, so pleasant to work with.
"Guatemala presents special challenges," Dr. Segreto concluded, "but also special satisfaction for a job well done."
