[Preservatives and dental caries. Can preservatives in food and beverages influence oral health?].

There has been a pronounced decline in dental caries in industrialized countries during the last decades. The most obvious explanation is exposure to fluorides. However, the decline started before fluorides were extensively used. Theoretically, a contributory factor may have been increased consumption of foods containing preservatives. The aims of the present study were to find out whether increased intake of preservatives has occurred, and to assess the effect of two commonly used preservatives, sorbic acid and benzoic acid, on bacterial growth and on plaque acidogenity in vivo. Results from five consumption reports from the Central Bureau of Statistics of Norway were used to estimate changes in consumption of basic foods containing the preservatives mentioned. A modified broth dilution method was used to determine the growth inhibitory effects on selected oral streptococci. Plaque-pH measurements were performed with a microelectrode to assess possible effects on acid production. Data pointed towards increased consumption of preservatives. Legal concentrations of preservatives inhibited bacterial growth. Similar concentrations of the preservatives had a negligible effect on acid production in dental plaque (0.4% W/V), whereas higher concentrations (2% W/V) had an inhibitory effect.