NIDR scientists led the field of connective tissue research during the 1960s and 1970s. In February 1971, a team led by Dr. George Martin announced the discovery of soluble collagen, or procollagen, which gives rise to collagen, the protein forming skin, bone, and connective tissue in the entire human body.

Seymour Kreshover led the NIDR intramural program before becoming director in 1966. Kreshover introduced developmental biology, facial anomalies, and oral medicine into both intramural and extramural programs, and brought timely attention to autoimmune and allergic disease, pain and anesthesiology, and social science and behavioral research. Kreshover launched the National Caries Program, furthering the Institute's initial public health mission, and retired in 1975.

In a 1964 paper in the Archives of Oral Biology, intramural researchers Harold Jordan and Paul Keyes published the results of experiments confirming that given a particular diet, a bacteria found in plaque would cause periodontal disease. Subsequent research identified the bacteria, Odontomyces viscous, and detected its presence in humans.

In 1960, NIDR intramural scientists Robert J. Fitzgerald and Paul Keyes published a Journal of the American Dental Association article entitled "Demonstration of the Etiologic Role of Streptococci in Experimental Caries in the Hamster." One of the most influential in the history of dental research, the paper demonstrated that tooth decay was both infectious and transmissible.

In December, scientists and clinicians gathered in Gatlinburg, Tennessee, to discuss craniofacial disorders, particularly cleft lip and palate, which are still among the most common birth defects. Funded by NIDR's first grant for the multidisciplinary study of cleft palate, the conference touched off a new research field and creation of university-based NIDR-funded cleft lip and palate interdisciplinary programs.

Carl J. Witkop, Jr. was a specialist in inherited dental abnormalities. By 1956, studies of a tightly-knit Southern Maryland community convinced Witkop that dentinogenesis imperfecta was hereditary. In 1957 Witkop established the NIDR Section on Human Genetics, the first intramural genetics laboratory at NIH and edited the first textbook on dental genetics in 1962.

As inventors devised ever-faster dental drills, concerns grew about damage to dental pulp. In the mid-1950s, NIDR scientists Harold Stanley and Herbert Swerdlow evaluated different tools, speeds, and coolants and set guidelines enabling widespread adoption of high-speed drills. This "applied" research effort made NIDR a leader in studies of the nerves, blood vessels, and connective tissues in the dental pulp.

Francis Arnold was Trendley Dean's assistant in the Grand Rapids fluoride study. Becoming NIDR director in 1953, Arnold continued Dean's emphasis on caries research and extended it into periodontal studies, genetics, and investigation of cleft lip and palate. Arnold expanded training and built up the intramural program, opening a dedicated lab in 1963. Arnold retired in 1966.

American Dental Association research fellow Edward Hampp was the first microbiologist at NIDR. In 1949 Hampp isolated the spirochete that caused acute necrotizing ulcerative gingivitis, or "trenchmouth," and laid the foundation for a strong periodontal disease program at NIDR.

Rachel Harris Larson was the first woman scientist in the NIDR intramural program. Larson began at the NIH Industrial Hygiene Laboratory in 1942 and was among the first 27 staff members hired by NIDR, earning M.S. and Ph.D. degrees in chemistry during off hours. Larson's research involved microbiological and genetic studies of dental caries in rats. Read the NIH Record story about Dr. Larson and her sister, “Dot” Murphy, a fellow long-time NIH employee.