Featherstone on ingested fluoride and tooth decay

PREVENTION AND REVERSAL OF DENTAL CARIES: ROLE OF LOW LEVEL FLUORIDE by JD Featherstone, Department of Restorative Dentistry, University of California at San Francisco, 94143, USA. jdbf@itsa.ucsf.edu / Community Dent Oral Epidemiol. 1999 Feb;27(1):31-40.

ABSTRACT
Dental caries is a bacterially based disease that progresses when acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the mineral, that is, demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors which include salivary calcium, phosphate and proteins, salivary flow, and fluoride in saliva can balance, prevent or reverse dental caries.

Fluoride works primarily via topical mechanisms which include (1) inhibition of demineralization at the crystal surfaces inside the tooth, (2) enhancement of remineralization at the crystal surfaces (the resulting remineralized layer is very resistant to acid attack), and (3) inhibition of bacterial enzymes.

Fluoride in drinking water and in fluoride-containing products reduces tooth decay via these mechanisms. Low but slightly elevated levels of fluoride in saliva and plaque provided from these sources help prevent and reverse caries by inhibiting demineralization and enhancing remineralization.

The level of fluoride incorporated into dental mineral by systemic ingestion is insufficient to play a significant role in caries prevention. The effect of systemically ingested fluoride on caries is minimal. Fluoride “supplements” can be best used as a topical delivery system by sucking or chewing tablets or lozenges prior to ingestion.

From the UCSF faculty profile of John D. Featherstone, PhD,MSc:
John Featherstone, MSc, PhD, is Professor of Preventive and Restorative Dental Sciences at the University of California, San Francisco (UCSF) and Dean of the School of Dentistry…His research over the past 34 years has covered several aspects of cariology (study of tooth decay) including fluoride mechanisms of action, caries risk assessment, de- and remineralization of the teeth, apatite chemistry, salivary dysfunction, caries (tooth decay) prevention, and laser effects on dental hard tissues with emphasis on caries prevention and early caries removal. He is currently active in implementing caries management by risk assessment in several dental schools across the nation.