Special Series: The Winds of Change in Dentistry-1950 and 2000

American science was remarkably productive from 1950 to 2000. In 1951, the chemist Carl Djerassi completed the first complete synthesis of progesterone. In 1960, the Food and Drug Administration approved the use of this hormone as a birth control pill. With the leadership of Betty Friedan in the early 1960s and Gloria Steinem in the early 1970s, the Women’s Liberation Movement marched forward. By the 1980s, women had become more empowered.

Women’s reproductive rights received another boost in 1973 when the US Supreme Court ruled in Roe vs Wade that abortion was legal. Greater civil rights for women affected their career choices. No longer limited to teaching and nursing professions as was the case for their mothers and grandmothers, women began entering the fields of medicine and law. Dentistry was no exception: the number of female applicants to US dental schools increased through the 1980s and 1990s. By 2007, women constituted 45% of students in American dental schools.

With the end of World War II, scientists turned their attention to basic problems in the biologic sciences, namely the mechanism of heredity transmission—the transference of traits such as eye and hair color. In 1942, Avery, McCarty, and MacLeod provided a major boost to this theory by publishing their findings that genetic material was made of DNA, not protein, as some had suggested. A second major advancement came 10 years later, when Watson and Crick published their paper that established the DNA structure and provided a mechanism to explain hereditary transmission. For the next 40 years, research in molecular biology continued, culminating in 2001 with the publication of the human genome sequence.

These discoveries were recognized in the 1980s and 1990s as challenges to traditional views of infectious diseases. Prior to 1950, medicine considered these illnesses to be caused by microbes—bacteria, parasites, and viruses. A few of these theories were supported by the success of antibiotics, such as penicillin. By 2000, the genetic constitution, or DNA sequence, was considered equally important. Genetics affected the body’s susceptibility and response to microbes. Subsequent discoveries revealed that some genetic abnormalities could cause cancer. For dentistry, the recognition that genetics might influence dental diseases, such as caries and periodontal disease, did not come as quickly. With time, these discoveries would set the stage for a new understanding of dental diseases and become the basis for the dental practice to advance in the 21^st century.

The practice of dentistry changed during these 50 years, paralleling the significant transformations in science, politics, and society. These evolutions had a significant impact on the dentist and patient, as well as the public’s perception of dentistry. One such innovation was the suction apparatus to extract saliva from the mouth. Patented by H.A. Adler in 1979, this device allowed the patient to recline. In addition to enhancing patient comfort this way, the dentist could sit during the procedure. Another advance was John Borden’s invention of the high-speed handpiece in 1957 (Figure 1). Upon its introduction to the marketplace in the 1960s, this instrument was easily accepted into the dental office because other innovations changed the patient’s experience. These included the advancements in local anesthetic chemistry and administration, improvements in impression materials, and M.H. Tsai’s discovery in 1980 of a gold alloy that fused better with gold and did not turn green in the mouth. Consequently, a dental visit in 1990 was quicker and less painful and produced more esthetically pleasing results compared with a visit in 1950. Consequently, Americans altered their perceptions of dentists. These changes encouraged more people to see the dentist and spurred an influx of young Americans to careers in dentistry.

During these 50 years, the dental profession produced other advances that helped save teeth. One was the discovery of fluoride’s effect on tooth structure, and another was the success of the campaign to supplement public water with fluoride. This achievement was as significant for oral health as vaccination and pasteurization were for general health. Another advancement was the success of endodontics, which formed in the 1930s and emerged in the 1960s and 1970s as a specialty that prevented thousands of tooth extractions. This also led to a reduced need for bridges and partial or full dentures.

Like other areas of society, dentistry was significantly affected by the invention of television, which was patented in 1927 by Philo Farnsworth. From 1950 to 2000, the effect of marketing toothpaste began to influence the American population. By the 1980s and 1990s, Americans were overwhelmed with pictures of movie stars and celebrities with beautiful, white, perfectly aligned teeth. These images compelled people to visit the dentist and more young Americans to attend dental school. These technological innovations from Novocain to television had a major effect on dentistry: from how it was practiced to what was practiced and even its depiction within society.

However, the biologic and bioscience discoveries of these 50 years did not impact either dentists or their practice. In contrast, many of these innovations emerged from the discovery pipeline, entered the medical marketplace, and are used daily in medical practices. Part 4 of the series will explore why dentistry has lagged behind medicine in adopting these bioscience innovations.

The author wishes to express his gratitude to Dr. Scott Swank, Curator, The Dr. Samuel D. Harris National Museum of Dentistry, for his review of the article and assistance with providing historical images.

Edward F. Rossomando, DDS, PhD, MS
Professor
University of Connecticut School of Dental Medicine
Farmington, Connecticut

Director
Center for Research and Education in Technology Evaluation
Farmington, Connecticut