Clinical and histologic characteristics of normal gingiva in dogs

Abstract

The aims of the present study were to establish normal gingiva in dogs, to characterize the clinical conditions prevailing and to stereologically describe the structural composition of the normal gingival tissues. Three beagle dogs were subjected to regular oral hygiene procedures during 15 weeks. Measurements of gingival fluid flow and the amounts of crevicular leukocytes served to clinically assess the gingival conditions. Semi‐and ultrathin sections from biopsies of normal buccal gingival tissues from premolars were subjected to stereologic analysis based on morphometric point counting procedures. Gingival normality was achieved in two of the dogs. The normal gingival tissue in these dogs was characterized clinically by abscense of gingival fluid flow and by a minute amount of crevicular leukocytes. A gingival sulcus was most often absent. The junctional epithelium was without rete pegs, and the entire gingival connective tissue was densely filled by homogeneous collagen fiber bundles. A few isolated inflammatory cells were present in the junctional epithelium and the adjacent connective tissue. No clusters of inflammatory cells forming an infiltrate could be observed. Stereologically, the gingival tissue comprised 48% epithelium and 52% connective tissue. The junctional epithelium occupied 10% of the gingival tissue and included a fraction of 2.8% occupied by leukocytes. The latter by volume comprised 50% neutrophilic granulocytes and mononuclear cells each. The connective tissue was composed of 67% collagen fibers, 14% free cells and 19% residual tissue. The composition of the connective tissue adjacent to the junctional epithelium differed somewhat from that of more central connective tissue fractions.

Pre-clinical Models for Oral and Periodontal Reconstructive Therapies

“…Large animals allow for the study of NMF in criticalsize defects that, by definition, do not heal spontaneously during the lifetime of the animal (Hollinger and Kleinschmidt, 1990). Another advantage of large animal models is that higher-order animals generally more closely simulate the anatomical, physiological, and pathological conditions found in humans (Schectman et al, 1972;Attström et al, 1975;Brecx et al, 1985;Hollinger and Kleinschmidt, 1990). Consequently, pre-clinical studies involving dogs and non-human primates are generally preferred by regulatory bodies for demonstration of the safety and efficacy of candidate NMF (Kaigler et al, 2010).…”

The Effect of Zinc Chloride on the Development of Gingivitis in Beagle Dogs Treated with Cetylpyridinium Chloride

“…Attstrom et al 1 have described the histologic characteristics of normal gingiva in beagle dogs, noting that normal gingiva displayed no gingival fluid flow clinically and relatively few inflammatory cells histologically. These same authors2 have described initial gingivitis in this model.…”

“…Fischman et al 1 determined that a 0.5% zinc citrate solution, in combination with 0.125% zinc tribromsalan significantly reduced dental plaque over a three-day period ineffective in reducing plaque formation when compared to 0.075% benzethonium chloride used as a rinse once per day over a ten-day period. Interestingly, the plaque formation observed with the addition of zinc chloride to benzethonium chloride in this study was comparable to that of the placebo group.…”

Development of animal experimental periodontitis models

“…Dog model is widely used for periodontal study because periodontal inflammation is common in dogs and its pathological characteristics are similar to those of periodontitis in humans [5]. Periodontitis of dogs arises naturally from gingivitis with the aging process, but the time of onset is unpredictable and the defects are inconsistent, which are considered to be the drawbacks of this model [6].…”

“…To study the phenomenon of periodontal inflammation and the effect of periodontal treatment, several animal models have been adopted [2-4]. Among these animal models, dogs are one of the commonly chosen models for periodontal study because of their high occurrence rate of periodontitis and the same etiologic factors as humans [5]. However, the natural periodontitis of dogs produces inconsistent periodontal lesions with an uneven extent and localization of periodontal inflammation [6].…”