Do the names Joseph Muhler and William Nebergall ring a bell? How about U.S. patent Nos. 3,445,567 and 2,876,166?

If the numbers don’t stand out, surely the invention they stand for does: fluoride toothpaste.

The National Inventors Hall of Fame is recognizing posthumously the dentists — Drs. Muhler and Nebergall — who helped develop and patent the invention credited by many as a significant factor in the widespread decline in caries that began in the 1970s.

They are among 19 who will be honored in Washington D.C. in May by the National Inventors Hall of Fame in partnership with the U.S. Patent and Trademark Office.

“The National Inventors Hall of Fame honors the innovation game-changers who have transformed our world,” National Inventors Hall of Fame CEO Michael Oister said in a news release.

Scientific research has shown that an optimal level of fluoride in community water is effective in preventing tooth decay by at least 25 percent in children and adults. This result led the Centers for Disease Control and Prevention to name water fluoridation one of Ten Great Public Health Achievements of the 20th century.

Furthermore, “home use of fluoride by brushing with fluoridated toothpaste also offers substantial protection,” said Dr. Norman Tinanoff, a member of the ADA Council on Scientific Affairs and professor of pediatric dentistry at the University of Maryland School of Dentistry. “More than 70 clinical trials show that fluoride toothpaste also is very effective in reducing dental caries. The benefit of fluoridated toothpaste is maximized by brushing twice a day.”

In the 1940s as an undergrad at Indiana University, Dr. Muhler, a dentist and biochemist, began studying fluoride and tooth decay, with the encouragement of his biochemistry professor Harry Day, according to the National Inventors Hall of Fame. Dr. Muhler “researched more than 150 fluoride compounds before establishing stannous fluoride as the most effective hardening and protective agent for tooth enamel.”

Dr. Muhler, who died at age 73 in 1996, worked with Dr. Nebergall, who used Dr. Muhler’s research to help develop stannous fluoride toothpaste. Dr. Nebergall “worked on the inorganic chemistry aspects, producing high-purity stannous fluoride and compatible abrasives,” according to the National Inventors Hall of Fame. He died in 1978 at age 63.

Thanks to their work, Crest toothpaste was introduced nationally in 1956 and became the first dentifrice that the American Dental Association evaluated and accepted for therapeutic effectiveness. The former ADA Council on Dental Therapeutics issued a report about evaluating the product, calling it “an effective anticaries dentifrice.”

Drs. Nebergall and Muhler contributed a number of papers to The Journal of the American Dental Association. To read them, visit JADA.ADA.org and search for their names.

Today, toothpastes that qualify to earn the ADA Seal of Acceptance must include fluoride. To see a complete list of products with the ADA Seal, visit AADA.org/Seal.

To learn more about Drs. Muhler and Nebergall and the other National Inventors Hall of Fame inductees, visit invent.org/honor/inductees/.