| 摘要 |
<p>The stannous salts of polyphosphonic acids are useful in combination with water-soluble fluorides in caries prophylaxis. They are added to toothpastes, mouthwashes, and chewing gum. The polyphosphonic acids are prepd. by treating acetylenic cpds. of formula : R1-(C triple bond C)m-CH2X with a hydrogen dialkyl phosphite and an alkali-metal promoter (e.g. Na.). R1 = H or CH2X; X = halogen, OH, or toluene-o-sulphonyl; m is 2, 3 or 4. The stannous salt is made by treating the acid with SnCl2. The anti-caries comp. contains 100-4,000 ppm F-, 15-10,000 ppm Sn2+ and 0.05-5 wt. % of the stannous polyphosphonate.</p> |
