Fluoride Action Network

US NIH gives over $3 million to NJ Dental School to do fluoride study in Ireland

Source: Press release from The University of Medicine and Dentistry of New Jersey | December 16th, 2008

NEWARK – A researcher specializing in pharmacogenetics at UMDNJ-New Jersey Dental School has been awarded a grant for more than $3 million to determine why the mineral fluoride is highly beneficial for dental and bone health in most children but causes permanent staining and weakens teeth and bones in others.

Water fluoridation has emerged as one of the top public health achievements in the 20th century, saving over $25 billion in dental treatment cost over the past decade alone. But scientists have become increasingly aware that the amount of fluoride needed for good health outcomes for some children is either too much or too little for others. At present, there’s no way to predict the right fluoride dose in advance. Discovering how to do this is the major goal of this new study.

The National Institutes of Health (NIH) awarded the five-year grant of $3,157,976 to Dr. Scott R. Diehl, director of the Center for Pharmacogenomics and Complex Disease Research at the UMDNJ-New Jersey Dental School. The project will evaluate some 3,400 school children ages 11 to 15 years in a region of Ireland where fluoride is added to drinking water. During the study, researchers will attempt to identify genetic and environmental risk factors for dental fluorosis, a condition characterized by permanent discoloration and weakening of tooth enamel. The study will also search for genes that influence risk of dental caries (tooth decay), which water fluoridation aims to prevent.

“Studies of human twins have shown that inherited differences are a major reason why some people have extensive tooth decay while others have no decay at all,” Dr. Diehl said. “Up until now, only a handful of places in the human genome have been searched for genes related to tooth decay and no searches at all have been conducted for fluorosis risk.”

The study will screen samples of saliva for harmful or protective bacteria and test for genetic changes that occur within DNA that cause inherited differences among individuals relative to enamel proteins and other biological pathways that involve fluoride. Dr. Diehl noted that his team’s study of fluorosis would be the first to use new techniques that allow investigators to search the entire human genome for inherited variation in fluorosis risk.

The study also will assess whether fluoride urinary excretion rates differ between dental fluorosis cases and controls and whether fluorosis susceptibility genes affect excretion rates, according to Dr. Diehl. “This represents a first step towards understanding the biological mechanisms underlying individual differences in fluorosis and caries risk.”

The findings from this study may also help to improve the oral health of Newark residents. Dr. Diehl recently began a similar study assessing risk factors for dental caries in area children who were treated at the UMDNJ-New Jersey Dental School. Though much smaller than the Irish project, “This local study will allow us to test whether the findings are unique to Ireland or apply more broadly to most populations around the globe,” said Dr. Diehl.

To arrange an interview with Dr. Diehl, please contact Jerry Carey, UMDNJ News Service, at 973-972-3000.

The University of Medicine and Dentistry of New Jersey (UMDNJ) is the nation’s largest free-standing public health sciences university with more than 5,600 students attending the state’s three medical schools, its only dental school, a graduate school of biomedical sciences, a school of health related professions, a school of nursing and its only school of public health on five campuses. Annually, there are more than two million patient visits at UMDNJ facilities and faculty practices at campuses in Newark, New Brunswick/Piscataway, Scotch Plains, Camden and Stratford. UMDNJ operates University Hospital, a Level I Trauma Center in Newark, and University Behavioral HealthCare, a statewide mental health and addiction services network.