The Tufts Dental School had weathered the crises and uncertainties of the First World War in spite of increased costs for maintenance and for materials necessary to fulfill its obligations to its students. Two developments under the leadership of Dean William Rice were particular sources of satisfaction. During the war the federal government, recognizing the importance of dentistry to the welfare of military personnel, gave dentists rank and pay equivalent to those of doctors. Then followed an investigation and classification of dental schools throughout the country, made on the recommendation of the office of the Surgeon General. The Tufts school received the highest rating (Class A); this entitled its graduates to take examinations for commissions in both the Army and the Navy. As a result, 280 men connected with the dental school entered military service. The quality of the training at the dental school also resulted in election to membership in the Dental Faculties Association of American Universities, in which there were only eight universities at the time. The Tufts school became the first department of a college to be thus honored. The Dental Educational Council of America placed the school in the Class A category in 1923.[37] 

The enrollment of the dental school had dropped sharply when the requirement of one year of college work had become effective in the fall of 1922. The smallest entering class in the history of the school (twenty-one) had resulted, and enrollment had not approached what was considered normal until 1924-25 when the number of entering students rose to seventy-eight. Tuition was set at $250, effective the following year. President Cousens' concern in the mid-1920's about the dental school was centered around the relatively low academic and professional standards that seemed to prevail in the school proper; he put most of the blame on the

To make matters worse, the dental school found itself caught between the demands of the Dental Educational Council of the American Dental Association and the plan recommended by the Carnegie Foundation. The Carnegie Report on Dental Education recommended for entrance two years in an accredited liberal arts college, a professional course of three years, and the organization of a one-year graduate course in dental specialties. The Dental Educational Council recommended, on the other hand, two years of college and a four-year professional course. New York State elected to adhere to the so-called "two-four" plan, which automatically made graduates of schools following the "two-three-graduate" plan ineligible to take the state licensing examination. Because the proportion of New York students in the Tufts Dental School was very high, the dental school reluctantly decided to conform to the New York requirements.[38]  No one knew what plan would eventually become the standard for a Class A rating until 1934, when the members of the American Association of Dental Schools voted to adopt the "two-four" plan, effective in 1937-38. Doubt was also cast on the status of the dental school by the insistence of the American Medical Association that the work of the school be completely separated from that of the medical school. Cousens vigorously disapproved of this policy of separation and was inclined "to take a rather firm stand" and continue to allow at least some dental school

The Tufts Dental School underwent some important changes in the early 1930's, although deficits continued to accumulate during the depression period. A complete modernization of the dental infirmary in 1931, involving the replacement of much equipment over thirty years old and expenditures of over $30,000, was made possible only by an appeal to dental school alumni; over 400 contributed or pledged to the Dental Alumni Fund. The dental school lost, by death in 1932, its dean of fifteen years, Dr. William Rice. Dr. Howard M. Marjerison, Associate Professor of Prosthetic Dentistry, after serving as temporary head, became dean in 1934.[39]  Under his leadership the teaching staff was reorganized and consolidated from fifteen semiautonomous departments into four major coordinated divisions: Operative Dentistry, Prosthetic Dentistry, Oral Surgery, and Orthodontia. A new Department of Clinical Medicine was also organized, in line with a renewed emphasis on the biological aspects of dentistry and a decreased emphasis on dental technique and mechanical procedures. Dean Marjerison was strongly in favor not only of developing dentistry as a branch of medicine but of encouraging clinical research. He felt that facilities offered through the cooperation of the Departments of Clinical Medicine, Dental Pathology, and Oral Medicine would be a satisfactory equivalent of conventional hospital facilities. The greatest and most immediate personnel need seemed to be sufficient adjustment in teaching loads to enable research to be carried on.

Although the dental school did not experience the same pressure as the medical school to require college degrees of its matriculants, the proportion of holders of a Bachelor's degree did increase markedly. Almost one-half of the entering class in 1936-37 had already earned an academic degree. Yet there was the uneasy feeling, expressed by both Dean Marjerison and President Cousens, that dental education still had some distance to go before losing its status as a "trade school" and gaining full university recognition.

[37] Tufts was one of the twenty schools out of the forty-eight examined that received such a rating.

[38] In 1926-27 there were ninety students from New York. In the following year, more entering students came from New York than from any other state; New Yorkers comprised one-third of the total enrollment that year.

[39] The infirmary at the dental school was named "The William Rice Infirmary" by the Trustees in honor of the late dean.