Some histological and histochemical observations on the connective tissue of chronically inflamed human gingiva

This investigation was undertaken during the tenure of a Research Fellowship in the Institute of Dental Surgery, University of London, and a Leverhulme Research Fellowship in the Department of Dental Science, Royal College of Surgeons of England. Some of the findings were included in a Thesis submitted to the University of London for the Degree of Doctor of Philosophy.
One hundred and fifty biopsies of human gingiva, removed randomly from patients undergoing gingivectomy, were examined in the light microscope. Cold microtome and paraffin sections were prepared. Eosin, Mallory's PTAH, acid solochrome cyanine and chlorantine fast red, the Gomori aldehyde fuchsin, resorcin fuchsin and orcein methods for elastic fibres, and silver impregnation were used to colour collagen fibres; fibrin was stained by the DMAB method, and mucosubstances by the paS, DMPD, alcian blue and the aldehyde fuchsin methods. All the interdental gingival septa exhibited an ulcerated col. The intercellular substance of the connective tissue was not separated in cold microtome sections, as in paraffin sections, and probably more faithfully reflected the state of the tissue in vivo . However, cell detail in paraffin sections was clearer than in cold microtome sections. The collagen fibres in inflamed connective tissue were found to disintegrate and to lose their affinity for stains with which they usually react, but were not coloured by stains for elastic fibres during the process, nor by the DMAB method. The distribution of neutral and acid mucosubstances was found to overlap in healthy connective tissue. Neutral mucosubstances became less reactive in inflamed areas, but the reactivity of acidic mucopolysaccharides, which could also be demonstrated by two of the three stains used for elastic fibres, increased at the periphery of these areas, and was thought to be associated with fibrogenesis.