Resistance of Human Gingival Collagen to Human Gingival Bacteria. ∗

Abstract

Summary

In 44 tests, in which untreated human gingival tissue from cases of periodontitis simplex was incubated for 10 days in broth with its indigenous microbiota, no breakdown of collagen could be detected either chemically or histologically. All other tissue elements, however, were stripped away. In concurrent controls, bovine Achilles'tendon, stored frozen and sterilized by ethylene oxide as in a previous investigation, was used as a substrate for the same microorganisms and underwent collagenolysis in 37 of 44 tests. Freezing, thawing, and sterilization of human gingival tissue with ethylene oxide rendered its collagen susceptible to degradation by its indigenous flora in 17 of 23 tests. This action of ethylene oxide was paralleled by a striking alteration of the reaction of the tissues to the Mallory-azan stain for connective tissue. The participation of true bacterial collagenases in periodontal disease has not yet been substantiated. Conclusions to the contrary have been based on the digestion of altered collagen by other proteases.