R. Schmid

Carbohydrates in Pooled Dental Plaque

Dental plaque was collected from approximately 3,500 schoolchildren, and immediately pooled and frozen. The lyophilized plaque was processed in several batches as follows:After an aqueous extraction the water-insoluble portion was further extracted with 1 N KOH. Both aqueous and alkaline extracts were further subfractionated by precipitation at different ethanol concentrations. Nature and composition of carbohydrates in sub-fractions were investigated using acid hydrolysis and end products were identified by gas liquid partition chromatography.29.6% of plaque dry weight, containing 6.9% carbohydrates, 1.2% nitrogen and more than 4% proteins, were water-soluble. The water-insoluble portion (67.1%), contained 11.3% carbohydrates and 7.4% nitrogen; in addition, 30.7% constituents insoluble in 1 N KOH were found. In all subfractions prepared by ethanol precipitations, substantial amounts of material other than carbohydrates were found. The sugar composition of hydrolysates showed glucose to be the main sugar constituent; however, small amounts of pentoses, other hexoses and disaccharides were also present. The water-insoluble matrix polysaccharides containing predominantly α-1,3 linkages were calculated to account for 1.35% of the plaque dry weight/ 5.6% of the plaque dry weight consisted of low molecular water-soluble carbohydrates. Glucose and oligosaccharides forming the bulk of this fraction were assumed to represent intermediates resulting from enzymatic breakdown of α-1,6-linked dextran. The high content of fermentable carbohydrates in dental plaque suggests that microbial activity is not limited by the supply of fermentable substrates.

Cariogenic effects of cooked wheat starch alone or with sucrose and frequency-controlled feedings in rats

Abstract Twenty-day-old Osborne-Mendel rats, super-infected orally with Streptococcus , mutans OMZ-176 and Actinomyces viscosus Ny 1, received 111 mg of one of the following diets 18 or 36 times daily for 33 days from a programmed feeding machine: (1) powdered sucrose × 36; (2) powdered sucrose × 18; (3) cooked wheat starch × 36; (4) a 1:1 mixture of cooked wheat starch : powdered sucrose × 36; (5) alternating meals of powdered sucrose and cooked wheat starch × 36; or (6) powdered sucrose × 18/cooked wheat starch × 18. During the 33-day experimental period the animals were administered 2 ml of a balanced liquid diet by stomach-tube twice daily. Cooked wheat starch alone was cariogenic, but less so than sucrose. Thirty-six alternating meals of powdered sucrose and cooked wheat starch were as cariogenic as 36 meals of sucrose. The 1:1 mixture of cooked wheat starch : powdered sucrose was as cariogenic or more cariogenic than an equal number of sucrose meals. The additive or synergistic effect was time-dependent; the block-feeding of 18 powdered sucrose/18 cooked wheat starch meals was less cariogenic than 36 sucrose meals.

Some Dental Effects of Xylitol under Laboratory and in vivo Conditions

In vitro, xylitol was not fermented by S. mutans and A. viscosus and had no effect on cell growth. Xylitol neither interfered with the utilization of sucrose by the two bacterial species nor inhibited bacterial colonization of rat molar surfaces in sucrose-containing broth. In a rat caries test, xylitol added to starch diets and starch-sucrose diets did not affect formation of bacterial agglomerates on rat molars. Rinsing with 10% xylitol solutions did not interfere with early plaque formation in young adults consuming their habitual diet. Telemetric recordings of interdental plaque pH showed that 10% xylitol rinses and xylitol chewing gum were non-acidogenic. Xylitol did not prevent rapid sucrose glycolysis. In a 40-day rat caries test, xylitol was non-cariogenic and seemed to reduce the cariogenic potential of sucrose administered simultaneously, however, the animals consuming xylitol diets suffered from severe diarrhoea and gained less weight. In another experiment, rats drank less when xylitol was added to the drinking water.

Effect of topical application of urea peroxide on caries incidence and plaque accumulation in rats.

100 μl of 10.00/o aqueous solutions of the test substances were applied topically 3 times daily to molar teeth in 23-day-old CARA rats previously inoculated with Streptococcus mutans

Effect on rat caries of endogenous and exogenous hydrogen peroxide.

A toothpaste containing sodium fluoride and enzymes activating the anti-glycolytic lactoperoxidase-thiocyanate system was without inhibitory effects in 3 independent rat caries studies on formation of

Effects of the Topical Application of Mutanase on Rat Caries

The effect of topically applied mutanase (α-1-3-glucan, 3-glucanohydrolase) on plaque formation and caries in rats was studied in two experiments. Compounds known to strongly inhibit dental caries whe

Effect of the length and number of intervals between meals on caries in rats.

Rats, orally inoculated with Streptococcus mutans OMZ 176 and Actinomyces viscosus Ny-1, received 18 meals daily of either sucrose, cooked wheat starch or a 1:1 m

Cariogenicity of Uncooked and Cooked Traditional African Foodstuffs in Rats

To test for the presence of a cariostatic agent the cariogenicity of cooked and uncooked home-prepared maize, factory-milled maize and factory-milled sorghum was compared to cooked wheat starch and su

Cariogenicity of Traditional African Foodstuffs (Maize, Beans, Sorghum, Brown Bread) on Rat Caries

The cariogenicity of the following traditional African foods was tested in a rat model system: cooked maize and beans, cooked maize and spinach, uncooked and cooked sorghum, both plus 20% sucrose and brown bread, as well as a control (wheat starch plus 50% sucrose). Plaque extent was low in all the test groups and caries incidence was almost zero in all groups except for the cooked wheat starch and 50% sucrose group. Comparison to earlier results suggests a possible cariostatic effect of sorghum but not for the other traditional foods.

The Effects of Topical Applications of Sugar Substitutes on the Incidence of Caries and Bacterial Agglomerate Formation in Rats

In four separate studies, 50% aqueous solutions of sugar substitutes (150 or 200 μl) were topically applied 3 or 5 times daily on molar teeth in rats receiving a low cariogenic diet (20% sucrose) <