This article originally appeared onThe Defenderand was republished with permission.
Guest post byBrenda Baletti, Ph.D.
Japan has achieved dramatic long-termdeclines in childhood tooth decay— despite never implementing nationwide water fluoridation and only recently recommending fluoridated toothpaste, according to a new study inBMC Public Health.
The research, by Yoshihisa Yamashita, D.D.S, Ph.D., of Kyushu Dental University, describes Japan’s experience as a “natural social experiment” that could reshape how public health experts address preventing dental cavities at the population level.
Unlike many other high-income countries, Japan has historically limitedfluorideexposure during childhood — which makes the country a “unique and underexplored case.”
Using decades of national dental survey data, the study found that average rates of tooth decay among Japanese 12-year-olds fell steadily over roughly 40 years.
Levels dropped from a peak nationalDecayed, Missing, and Filled Teeth (DMFT) index scoreof 4.75 in 1984 to just 0.53 in 2023 — “well below levels historically reported in populations exposed to systemic fluoride through community water fluoridation,” according to the study. DMFT is the standard international measure of decayed, missing and filled teeth.
“This trajectory unfolded in the absence of nationwide community water fluoridation,” the paper states. High-fluoride toothpaste was not widely available in Japan until 2017 and was not officially recommended for school-aged children until 2023, according to the study.
Dr. Griffin Cole, conference chairman of the International Academy of Oral Medicine and Toxicology, said the study’s method of using national dental records across an entire population, rather than measuring fluoride exposure among a small group, provided important evidence on oral health.
“By examining real-world outcomes, Yamashita’s analysis provides strong evidence of what we already know: Oral health can improve through nutrition, behavior and broader public health measures, rather than adding fluoride chemicals to our water supplies,” he said.
Source: The Vigilant Fox
