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Distribution and ultrastructure of subgingival plaque in beagle dogs with gingival inflammation
Author(s) -
Theilade Jørgen,
Attström Rolf
Publication year - 1985
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.1985.tb00420.x
Subject(s) - beagle , ultrastructure , bone decalcification , gingivitis , electron microscope , pathology , biology , premolar , anatomy , dental plaque , dentistry , medicine , genetics , physics , molar , optics
The present study was designed to describe the distribution and ultrastructure of subgingival plaque in beagle dogs in an attempt to establish a correlation between these deposits and some aspects of the adjacent soft tissue destruction. Biopsies comprising one premolar with adjacent buccal gingiva were obtained from six beagle dogs approximately two years old with clinically diagnosed chronic gingivitis. After prefixation and decalcification the biopsies were cut axially to yield 0.5 mm thick slices, after which the tissue was postfixed and embedded in Epon. From each dog one slice was randomly selected for the study. Each block was semi‐serially sectioned to provide axial sections. From the blocks of five dogs one semithin section for light microscopy and an adjacent thin section were obtained for every 50 μm in mesiodistal direction. From one dog only semithin sections for light microscopy was cut, and a section retrieved for each 10 μm interval. Light microscopy revealed that in three of the biopsies examined no subgingival plaque colonies were present on the tooth. In three biopsies, varying numbers of subgingival plaque colonies were present. Electron microscopy revealed that in one of the biopsies Gram‐negative cocci or rods predominated in all subgingival colonies observed. In the other biopsy in which subgingival colonies were present, spirochetes predominated. In all five biopsies examined in the electron microscope a few single bacteria or small groups of microorganisms were observed either between the tooth and the junctional epithelium or between the most superficial cells of the latter. Evidence of phagocytosis of microorganisms was seen, but to a limited extent. Single organisms were regularly encountered adjacent to the tooth surface in the region between the most apically established plaque colony and the first intact hemidesmosome. The distance from the gingival margin to the most apical subgingival plaque averaged 0.25 mm (S.D. ± 0.05 mm). The distance from the gingival margin to the most coronal hemidesmosome was 0.43 mm (S.D. + 0.06 mm), and this distance did not seem to be influenced by the presence or absence of subgingival plaque colonies in the section or in the biopsy slice.