maleic-acid and Dental-Plaque

The sorbitol fermentation by Actinomyces viscosus and Actinomyces naeslundii was studied with washed sorbitol-grown cells. The fermentation was followed by titration of acids produced at pH 7.0 under anaerobic conditions. Metabolic end-products and intracellular levels of NAD, NADH and glycolytic intermediates during the fermentation were also analyzed. Cell extracts were examined for certain enzyme activities. Bicarbonate was required for acid production from sorbitol and from a mixture of glucose and sorbitol. Malate and fumarate could also support the acid production of A. viscosus. The main end-products were succinate and lactate but not ethanol. Cell extracts showed no activities of alcohol and aldehyde dehydrogenases, but they had activities of malate dehydrogenase and fumarate reductase. In the absence of bicarbonate, malate or fumarate, the intracellular NADH/NAD ratio increased and the levels of 3- and 2-phosphoglycerate and phosphoenolpyruvate decreased. The results indicate that oral sorbitol-fermenting actinomyces lack the ethanol pathway that can contribute to NADH oxidation. To maintain intracellular redox balance during anaerobic sorbitol fermentation, these bacteria can oxidize surplus NADH through a succinate pathway.

Topics: Actinomyces; Actinomyces viscosus; Dental Plaque; Fermentation; Fumarates; Glucose; Glycolysis; Humans; Lactates; Maleates; NAD; Sodium Bicarbonate; Sorbitol; Succinates

An electrostatic complex of 0.1% benzethonium chloride (BTC) plus 0.05% copolymer of methoxyethylene and maleic acid was evaluated in vitro for antibacterial effect. The complex by itself showed as much antibacterial activity as 0.1% BTC. The adsorption of 14C-BTC on saliva-coated hydroxyapatite disks and teeth in vitro was lower from the complex than the BTC solution, although in vivo activity was the same. The complex, BTC, and polymer solutions were evaluated in a 28-week study in 16 beagle dogs against plaque, gingivitis, and calculus formation. BTC and the complex significantly (alpha = 0.05) reduce plaque and gingivitis. There was no significant difference between the two active groups. BTC (0.1%) significantly increased calcified deposits at 22-28 wk compared to the water control group, while the complex and the polymer groups showed significantly (alpha = 0.05) less calculus. Thus, the complex was not only effective in vivo, but also significantly (alpha = 0.05) reduced tendencies of cationic antibacterials to induce calcified deposits on teeth.

Topics: Adsorption; Animals; Bacteria; Benzethonium; Dental Calculus; Dental Plaque; Dogs; Gingivitis; In Vitro Techniques; Maleates; Polyethylenes; Quaternary Ammonium Compounds