In a research study Willis16 reports dental calculus is known to form routinely in most primates, including lemurs and baboons. Dental plaque, which is comprised predominantly of oral microorganisms with variable amounts of food debris and microbial remnants, forms continuously on tooth surfaces, as well as on existing calculus deposits.6
Because of the high concentration of calcium and phosphorus in saliva, dental plaque begins to calcify shortly after the microorganisms complete their life cycle (i.e., within three days of initial formation of plaque).15 Thus, since dental plaque forms continuously, calculus formation also may be considered a continuous process.
The presence of calculus is quite commonly associated with gingival inflammation, which often progresses to periodontal disease frequently resulting in the destruction of alveolar bone and tooth loss. Although calculus is not a primary factor in the etiology of periodontal disease, it is known to be a contributing factor since it interferes with the normal removal of dental plaque during mastication and its presence serves as a physical irritant to the gingival soft tissues.
Recent investigations have reported that the prevalence of periodontal disease in gorillas housed in captive colonies ranges from 67-100%.8,9 It has also been reported that captive animals have a higher prevalence of periodontal disease than animals living in their natural habitat.5
Once formed, calculus can only be removed with a professional dental prophylaxis including scaling and polishing. Dental calculus may be prevented by the meticulous removal of dental plaque on a regular basis (i.e., at least twice weekly.)
Relatively few reports have been published regarding measures to reduce dental calculus formation in exotic animals. Fagan1,2 reported that a firm-textured natural diet cleaned the teeth of carnivores more effectively than a commercial meat-based feline diet. Similar observations were made in captive timber wolves by Vosburg and coworkers14.
In another investigation, Haberstroh et al.4 provided beef femur bones once or twice weekly to captive Amur tigers (Panthera tigris altaica) and reported that the twice weekly regimen resulted in a significant reduction in calculus formation with significantly improved gingival health as compared to a control regimen without the provision of bones. Thus these prior reports have emphasized the importance of the texture of the diet for facilitating oral cleansing during routine mastication.
In dogs, research has demonstrated that the use of sodium hexametaphosphate on dry snack foods for domestic dogs results in a reduction of calculus of about 50-80%10 and similarly resulted in a 46% reduction when added to a snack biscuit11.
Research conducted at the Indiana University School of Dentistry16 and Indianapolis Zoo in ring-tailed and collared lemurs (Lemur catta and Eulemur fulvus collaris) and two studies in baboons (Guinea baboon) investigated a practical approach for calculus prevention. During the six-month study the primates were given a thorough dental prophylaxis at test initiation and were fed either a control diet or one with DentaGuard™. At the conclusion of the tests, all animals were anesthetized and examined for clinical calculus independently by two examiners.
The results? When the animals were provided the DentaGuard™ diet a statistically significant reduction in calculus formation was observed in the lemur study; these reductions were 62% and 61% for Examiners 1 and 2, respectively. At 7.5 weeks, the baboons similarly had statistically significant reductions in calculus formation of 48% and 49%. No clinically significant changes were observed in bodyweights or in blood chemistry.
A reduction of dental calculus formation reduces the time necessary to scale teeth. It also reduces probing depth which promotes healthier gums. Primates display fewer gum line cavities and loss of teeth. The studies also revealed that the addition of DentaGuard™ had no impact on the palatability of any of the MAZURI® products. In taste tests, primates displayed a marked preference for the unique, easy to hold shapes and literally ate them up. Response from zoos in the studies indicated MAZURI primate diets promoted good feed intake--which helped maintain the good condition of all animals.