In this blog article, we look at the modern dental history of the 20th century. This text serves as the first installment of a two-part document--the first covering the front half of the 20th century, from 1900 through 1949. The next AlgerBlog will round out the 1900s by covering dental developments from 1950 through the rest of the century. This two-part blog continues our exploration of “modern” dental history, which began with the previous AlgerBlog article “Dental History: Modern Dentistry of the 19th Century,” which in turn was set up by the article “Dental History: Dentistry in the Age of Enlightenment.” Our look at “Ancient Dentistry” completes the historical accounts of dental history, practice, profession, and conceptualizations currently available on the AlgerBlog. If you’ve not read the entire series, we invite you to do so at algerinc.com.
The first half of the 20th century was a pivotal period for dentistry, marked by significant advancements in technology, public health, and the professionalization of the field. Understanding this era provides insight into how the field of dentistry evolved during this time and how societal attitudes toward oral health followed this upward trend of modernization.
Developments in 20th Century Dentistry
Continuing 19th Century Dentistry Traditions
Dentistry of the 19th century was heavily defined by the discovery of essential modern dental tools, such as anesthesia, and the formation of formal dental associations, including the American Dental Association (ADA). The earliest years of the 20th century were defined heavily by the expansion of these 19th-century contributions. The ADA grew its influence in promoting standardized education and ethics within the profession, and formal dental education offered through dedicated dental schools and universities became increasingly common. 
Anesthesia
While 20th-century dentists continued to use dental anesthetics established in the previous century, such as ether, nitrous oxide (laughing gas), and cocaine, the early 1900s also saw innovation in this area with the discovery of a new, safer anesthetic option: Novocain. German chemist Alfred Einhorn discovered procaine (which was trade named Novocain) in 1904 while researching anesthetics. Novocain proved to be a comparable aesthetic alternative to the ever-popular cocaine and one that did not carry its predecessor’s negative health effects and addiction concerns. Einhorn patented his finding in 1906, and shortly thereafter, Novocain became the standard local anesthetic for dentists of the day.
Novocain’s superiority as a local anesthetic remained until the 1940s when Swedish chemists Nils Löfgren and Bengt Lundqvist invented lidocaine in 1943. Lidocaine provides the same level of local anesthetic as Novocaine, but it takes effect much more quickly, lasts longer, and has fewer recognized side effects. Thus, lidocaine became and remains the industry standard.
X-ray Technology
Wilhelm Conrad Roentgen, a Professor at Wuerzburg University in Germany, discovered X-rays in 1895. By the early 1900s, dental radiography was beginning to emerge as a diagnostic tool. This innovation allowed dentists to identify problems beneath the surface of the gums and teeth, significantly improving diagnosis and treatment planning. However, the risks associated with radiation exposure were not fully understood at the time, leading to later advancements in safety protocols.
The Popularization of Preventive Dentistry
The 1900s also saw a shift in focus towards preventive dental care, which significantly amended the conceptualization of dentistry by both practitioners and patients. With increasing awareness of the link between oral health and overall health, dentists began emphasizing the importance of regular check-ups and preventive measures, while new inventions, advancements in dental technology, and new knowledge pushed patients into a modern area of active dental involvement.
The Role of Dental Education in Prevention
While some historical dentists explored--even promoted--preventative dentistry in previous centuries (see: John Greenwood), these examples are outliers of their times. By the early 20th century, however, dentists and scholars were actively promoting preventative knowledge and practice. For instance, Thaddeus P. Hyatt, known as "The Father of Preventative Dentistry," encouraged dentists to help patients prevent tooth decay. Hyatt was also an early advocate for the acceptance of dental hygienists, a position that was formally launched when Dr. Alfred Civilion Fones opened the first dental hygiene school in Bridgeport, CT in 1913. Fones also began the Bridgeport Demonstration Project, which employed his graduates to provide dental care in public schools. Additional schools and programs followed in Connecticut’s wake, training hygienists and emphasizing the importance of cleanings and patient education in preventing oral disease.
Fluoride and Cavity Prevention
In the 1930s, research began to reveal the relationship between fluoride and dental health. Although fluoride was not yet widely used in dental products, the groundwork for its future incorporation into dental care was being laid. Concerns about high fluoride levels in discarded mine water led to epidemiologic studies conducted by the newly formed National Institute of Health (NIH) to determine what health effects high fluoride concentrations could have on the general public. US Public Health Services officer and founder of the NIH’s Dental Hygiene Unit, Dr. H. Trendley Dean, led this research and discovered a causal link between high fluoride intake and “dental fluorosis,” damage to the tooth enamel that is most commonly seen as cosmetic discoloration. While these findings initially spurred a public health concern, Dean’s continued research ultimately determined that the beneficial effects controlled levels of fluoride intake have on preventing tooth decay far outweigh the risk of dental fluorosis. This pivotal discovery introduced fluoride as a staple ingredient in dental care.
Water Fluoridation
Heavily influenced by Dean’s findings, the introduction of fluoridated water began to gain momentum in the late 1940s, with communities starting to adopt fluoride water fluoridation programs by 1945. The cities of Grand Rapids, MI; Newburgh, NY; Evanston, IL; and Brantford, Ontario in Canada led the charge as the first North American cities to start adding sodium fluoride to their public water systems. By 1948 (the same year the National Institute of Dental Research was formed), evidence from these studies showed significant reductions in cavities in populations with fluoridated water, leading to expansions of water fluoridation and other public health initiatives promoting fluoride’s use as an effective cavity preventative. 
The Toothbrush
The toothbrush was another preventative tool that 20th-century patients had to protect their teeth from decay. Bristle toothbrushes have been in use since their invention in China in 1498. Boar bristles were the most popular material for pre-20th-century toothbrushes. However, in 1938, Dupont de Nemours introduced the first nylon toothbrush, which it branded “Dr. West’s Miracle Tuft Toothbrush.” Following the end of WWII, returning soldiers brought with them the modern preventative toothcare practices that wartime dentists had taught them, further expanding the application of preventative dental healthcare across the nation and making the modern toothbrush a central tool in combating cavities at home.
A Transformative Era
The years from 1900 to 1949 were transformative for dentistry. What started as an era carrying forth the traditions of the previous century gave way to breakthrough innovations. Key advancements in anesthesia and X-ray technology gave dentists new tools that set the stage for modern dental practices. New education and discoveries about dental hygiene emphasized the importance of preventive care, changing how both practitioners and patients approached oral health. We will continue charting the advancements of modern dentistry of the 20th century in the next AlgerBlog, which will look at the second half of the 1900s. Please visit algerinc.com to continue your education of dental history, learn about other interesting topics, and--if you’re a practicing dentist or orthodontist--read about Alger Inc.’s prized piece of dental technology: the AlgerLight with LED.