A bitewing radiographic study of a population of diabetic and nondiabetic rhesus monkeys

Effects of caloric restriction on inflammatory periodontal disease

OBJECTIVE

Dietary caloric restriction (CR) has been found to reduce systemic markers of inflammation and may attenuate the effects of chronic inflammatory conditions. The purpose of this study was to examine the effects of long-term CR on naturally occurring chronic inflammatory periodontal disease in a nonhuman primate model.

METHODS

The effects of long-term CR on extent and severity of naturally occurring chronic periodontal disease, local inflammatory and immune responses, and periodontal microbiology, were evaluated in a cohort of 81 (35 female and 46 male; 13-40 y of age) rhesus monkeys (Macaca mulatta) with no previous exposure to routine oral hygiene. CR monkeys had been subjected to 30% CR for 13-17 y relative to control-fed (CON) animals starting at 3-5 y of age.

RESULTS

Same sex CR and CON monkeys exhibited similar levels of plaque, calculus, and bleeding on probing. Among CON animals, males showed significantly greater periodontal breakdown, as reflected by higher mean clinical attachment level and periodontal probing depth scores, than females. CR males exhibited significantly less periodontal pocketing, lower IgG antibody response, and lower IL-8 and ss-glucuronidase levels compared to CON males, whereas CR females showed a lower IgG antibody response but comparable clinical parameters and inflammatory marker levels relative to CON females. Long-term CR had no demonstrable effect on the periodontal microbiota.

CONCLUSION

Males demonstrated greater risk for naturally occurring periodontal disease than females. Long-term CR may differentially reduce the production of local inflammatory mediators and risk for inflammatory periodontal disease among males but not females.

Non-human primates used in studies of periodontal disease pathogenesis: a review of the literature

The inability to examine initiation and progression of periodontal disease and to assess certain therapies in humans has led to a great interest in the use of animal models in periodontal research. Some of the most prominent animals used are non-human primates. This article reviews the characteristics of non-human primate models in periodontal health, in the transition from health to gingivitis to periodontitis, and in experimental gingivitis and periodontitis. Where possible, the results of these studies are compared with results from human studies. Only a few studies have compared in detail the anatomy, physiology, immunology, and tissue interactions in monkeys with those of humans. With the exceptions of differences and variations in size of the dentition, the number of each tooth type as well as larger canines, presence of diastemata between anterior teeth, and an edge-to-edge relationship of the incisors, the dental and periodontal anatomy of non-human primates seem quite similar to that of humans. Clinically healthy gingiva can be established and maintained in non-human primates, and gingivitis as well as periodontitis occur in these animals. It is possible to induce experimental periodontitis by placement of peri-dental silk ligatures or orthodontic elastics as well as by surgical removal of alveolar bone. Although the most appropriate model for studies of periodontal disease pathogenesis in non-human primates appears to involve the application of silk ligatures, some difficulties may occur in establishing periodontal break-down by using this model. Many clinical, histological, microbiological, and immunological characteristics of spontaneous and experimental marginal inflammation in most non-human primates are similar to those in humans. The most significant differences between small non-human primates and humans are the very limited number of lymphocytes and plasma cells in the inflammatory infiltrate of squirrel monkeys (Saimiri sciureus) and marmosets. Therefore, the use of squirrel monkeys and marmosets may not be appropriate in many studies of periodontal disease pathogenesis. The most significant microbial differences between macaque species and humans are a lower proportion of Actinomyces species, the presence of a catalase-producing Prevotella melaninogenica strain, and the high carrier rate for Actinobacillus actinomycetemcomitans in subgingival plaque of macaque species. The significance of these differences is presently unknown. It is concluded that the use of many non-human primate species due to the apparent close anatomic and biologic similarities to humans is appropriate in experimental studies of periodontal disease, provided the use of laboratory animals is requisite and lower species are not applicable.(ABSTRACT TRUNCATED AT 400 WORDS)

Relation of diabetes control to periodontal pocketing and alveolar bone level

The periodontal health status of 50 diabetic and 53 control subjects was examined. The diabetic group was further divided into three subgroups according to the control of diabetes. There were no significant differences between the whole diabetic group and the control group as regards the frequency of pockets and alveolar bone level. A comparison between the controls and the diabetic subgroups revealed that the well-controlled diabetic patients had better periodontal health than the controls. Within the diabetic group, the prevalence of pockets declined as the control of diabetes improved; the decrease in the number of pockets on bleeding surfaces and on surfaces containing subgingival calculus was statistically significant. Better periodontal health seems to be connected with good control of diabetes, indicating better resistance of periodontal connective tissue and alveolar bone.

Investigation of the relationship between clinically detected loss of attachment and radiographic changes in early periodontal disease

A total of 383 students, ages 12-16, were examined clinically to determine periodontal attachment loss by a trained examiner, utilizing standard techniques. 70 of these were selected, for whom bitewing radiographs were available for assessment of early alveolar bone loss by 2 radiologists and a general dentist, utilizing 4 criteria. The results indicate poor agreement between clinical and radiographic diagnoses by the 3 examiners. Variations were also found in the diagnosis of pathologic sites utilizing radiographs. The data indicate that bitewing dental radiographs were a poor screening or diagnostic procedure for the assessment of early periodontal disease in adolescents.