Faculty Bibliography

History of Dentistry starts from the moment the Late Paleolithic Man used a toothpick fashioned from a bone or wood splinter, or the moment our human ancestors began to manipulate the surface of a tooth to remove its retentiveness, so food does not get stuck. That was at least 14,000 years ago, based on available evidence. The current timeline, compiled in this article, is one of many published over the years. However, this timeline incorporates three new strategies. First, it extends to select medical and fundamental dental discoveries, as the History of Dentistry can only be told with the main events within the History of Medicine. Second, it is more detailed (350 entries) than any previous timeline the author has encountered. Third, several critical primary references to support events listed in this timeline characterize this effort. Finally, 130 illustrations are included to improve the visualization of dates. The manuscript also includes a new display of the five main stages of dentistry throughout its history.

Responses to capsaicin are reduced following repeated exposure, a phenomenon known as capsaicin desensitization. Heavy consumers of chilies consistently report reduced oral burn relative to infrequent consumers, presumably due to chronic desensitization. However, the mechanism(s) underlying capsaicin desensitization remain poorly understood. We hypothesized that reduced response to capsaicin due to repeated oral exposure may result from a change in the expression of the capsaicin receptor (TRPV1) gene. To test this, we conducted two longitudinal desensitization studies in healthy human volunteers. In Study 1, 51 adults completed a 17-day capsaicin desensitization protocol. The study consisted of three in-person visits where they were asked to sample stimuli, including 3, 6, and 9 ppm capsaicin, and rate intensity on a general labeled magnitude scale (gLMS). Between days 3 & 17, participants rinsed at home with 6 ppm capsaicin (n = 31) or a control (n = 20) solution (20 uM sucrose octaccetate; SOA) twice a day. Before and after the oral exposure protocol, a clinician collected fungiform papillae. Participants randomized to the capsaicin rinse showed a statistically significant reduction in oral burn ratings that was not observed in controls, indicating repeated low-dose exposure can systematically induce desensitization. TRPV1 expression was not associated with reported capsaicin burn, and there was no evidence of a decrease in TRPV1 expression following capsaicin exposure. In Study 2, participants (n = 45) rinsed with 6 ppm capsaicin in a similar protocol, rating capsaicin, vanillyl butyl ether (VBE), cinnamaldehyde, ethanol, menthol, and sucrose on days 1, 3, & 17. Burn from capsaicin, VBE, cinnamaldehyde, and ethanol all showed a statistically significant change - capsaicin, VBE and cinnamaldehyde burn all dropped ∼20 %, and a larger reduction was seen for ethanol - while menthol cooling and sucrose sweetness did not change. Collectively, this suggests reductions in oral burn following chronic capsaicin exposure generalizes to other stimuli (i.e., cross desensitization) and this cannot be explained by a change in TRPV1 mRNA expression. More work is needed to elucidate the underlying mechanism for capsaicin desensitization in the oral cavity.

If one could attend the same College of Dentistry repeatedly, every twenty years, starting in 1880, the evolution and comparison of student life would be historically meaningful. Such a time travel, as a perpetual dental student through 140 years, is the purpose of this paper. To illustrate this unique perspective, New York College of Dentistry, was chosen. This large East-Coast private school has been in existence since 1865, and reflects the typical dental educational environment at that time. The changes that occurred over 140 years, however, may or may not be typical of most private dental schools in the United States due to a multiplicity of factors. Likewise, the life of a dental student has changed over the past 140 years, as dental education, oral care, and dental practice have significantly evolved.