Use of the feed additive sodium hexametaphosphate to prevent dental calculus in squirrel monkeys (Saimiri spp.)

Dental calculus and associated periodontal disease are serious clinical pro blems in captive squirrel monkeys. Calculus begins to appear as early as 2 years of age, with subsequent development of periodontal disease, dental ab scessation, tooth loss and other sequelae, When used as a feed additive, so dium hexametaphosphate (HMP) retards the growth of calculus on previously c leaned teeth in rhesus monkeys, lemurs, and other species. We wanted to det ermine whether HMP would reduce dental calculus in squirrel monkeys (Saimir i spp,) whose teeth had not been pre-cleaned. The study animals were divide d into two groups. One received a standard diet; the other received an iden tical diet containing the HMP additive at a concentration effective in othe r primate and non-primate species that had received dental cleaning prior t o treatment with HMP, Teeth were graded for extent of calculus formation at the start of the study and at 3 and 6 months during HMP treatment. We comp ared the results from the two groups both by total score per animal and acc ording to tooth type (e.g., incisors versus incisors in test and control gr oups), At the end of 6 months, dental calculus did not differ significantly between the experimental groups, Therefore, we conclude that HMP is ineffe ctive in squirrel monkeys with preexisting dental calculus.