Sulfonated aromatic formaldehyde condensation polymers as dental plaque barriers

An oral hygiene composition comprising an effective amount for preventing deposition of dental plaque on teeth of a sulfonated condensation polymer of formaldehyde with an aromatic compound, said polymer having repeating units selected from the group consisting of structure (A), ##STR14## wherein R.sub.1 and R.sub.2 are each independently selected from the group consisting of hydrogen, linear or branched alkyl of up to 20 carbon atoms, alkoxy of 1-20 carbon atoms, fluorine, chlorine, and bromine, provided, however, that in structure (B) R.sub.1 and R.sub.2 cannot both be hydrogen;

• R.sub.3 is hydrogen or an alkoxy group of up to 20 carbon atoms;
• X is a linkage selected from the group consisting of a direct covalent bond between the aromatic rings, a lower alkylene of 1 to 5 carbon atoms, a lower alkylidene having 2 to 5 carbon atoms, oxygen, sulfur, and O(CH.sub.2).sub.n O, where n is an integer from 2 to 20;
• p is from about 0.4 to about 1.2, the sum of q and r is between about 0.8 and about 2.4 and M is selected from the group consisting of lithium, sodium, potassium, calcium, magnesium, zinc, aluminum, hydrogen, ammonium and substituted ammonium ions derived from pharmaceutically acceptable organic amines, said polymer having a molecular weight in the range of from about 500 to about 10,000, in a pharmaceutically acceptable oral hygiene vehicle compatible with said polymer.