The effects of five different intense sweeteners on the growth and metabolism of mixed cultures of dental plaque microorganisms or a pure culture of Streptococcus mutans NCTC 10449 were studied (a) in peptone liquid media, (b) in agar media by the zone inhibition method and (c) in tryptone soya medium by a modification of the minimum inhibitory concentration method. Acesulfam-K and cyclamate showed no activity. The effect of Talin was obscured by its tendency to precipitate from solution. Only aspartame and saccharin had any inhibitory action, with aspartame the more effective in the mixed plaque cultures and saccharin the more effective against S. mutans.

Boiled sweets formulated with Lycasin® were compared with conventional sugar-base sweets. Incubated in media containing solutions of the sweets, mixed cultures of oral microorganisms produced less polysaccharide and acid, with significantly less demineralizing action on dental enamel and hydroxylapatite, from the Lycasin than from the sugar-base products. In comparison with these differences, the effects of changing the flavouring acid combinations in the sweets were minor, but levels of citric and malic acids as high as 1.00% showed some inhibition of the activity of the oral microorganisms.

No abstract

Five new formulations of water ice lollies with a high-phosphorus (low Ca) supplementation ratio were tested for their erosiveness of dental enamel or hydroxylapatite in vitro. Compared with the basic unsupplemented lolly, all five formulations that had been prepared with additional calcium and phosphorus, but in a low Ca/P ratio, as potential inhibitors of demineralisation, were associated with significantly less attack on dental mineral, as measured by the dissolution of calcium and phosphorus.

In response to concern over the sugar content and possible dental effects of infants' rusks, a programme of research was undertaken to compare six different kinds of rusk with respect to (a) their cariogenicity in caries-active laboratory rats; (b) their capacity to serve as substrates for acid production by oral microorganisms, and the attack of this acid on dental mineral; (c) the adhesiveness of the rusks to the enamel surface. The caries scores in the animal experiments ranged from very high, with rampant dental destruction, for 31%-sucrose rusks, down to virtually non-cariogenic on a zero-sucrose variety. With only one anomaly, cariogenicity correlated well with sucrose content. The results of the studies in vitro showed good general agreement with the animal data. The sucrose in the rusks, rather than their content of other sugars such as glucose, maltose and lactose, etc, emerged as a major factor in determining their effect on teeth, but cereal components can also play a part in governing adhesiveness and fermentability.