With dual training as both an M.D. and D.D.S., Dr. Dennis was an advocate of concurrent training in scientific subjects for dental and medical students. There had been unsuccessful attempt to found a dental school in San Francisco in the 1870s, but Dr. Dennis persisted, corresponding with eastern colleagues at Penn and Harvard to plan an optimal dental school for the West. He worked closely with the UC Medical Department to develop a dental school in association with the University of California, and by 1881 the medical faculty presented an appeal to the Regents to establish such a school, stating that, “Dentistry is an important collateral branch of medical science…and dental education is necessary for the public good.” With the support of the medical faculty and the promise of shared instructional space in the Toland Medical Building, the Regents approved the request and the first class of twenty-six students matriculated in 1882. Six of seven members of this first faculty held M.D. degrees and only two held the degree of D.D.S., a fact which reflects the close alliance of dentistry and medicine in the nineteenth century. S. W. Dennis served as Dean of the UC College of Dentistry during its first year (1881-1882), and also from 1883-1885. During this time dental instruction was closely allied with the medical curriculum and both lecture and clinical training took place in the Toland Medical Building.
In 1896 Dr. Dennis severed his connection with the College of Dentistry in the midst of a debate with “more progressive faculty” over proper dental curriculum. He died of pneumonia at the age of seventy, on January 20, 1907.