Diseases of the soft structures of the teeth and their treatment; a text-book for students and practitioners . same poisonous nature, nematter how or where they are obtained, while the ptomains varywith the nature of the substances from which they are are \cr\ labile substances, and they are readily destroyed NECROSIS AND GANGRENE OF THE DENTAL PULP 167 by heat, direct sunlight and oxygen. Antibodies or antitoxins canbe prepared against toxins, but not against ptomains. As veryfew bacilli are known that produce specific toxins, it is plain whyso few true antitoxins have been art
Diseases of the soft structures of the teeth and their treatment; a text-book for students and practitioners . same poisonous nature, nematter how or where they are obtained, while the ptomains varywith the nature of the substances from which they are are \cr\ labile substances, and they are readily destroyed NECROSIS AND GANGRENE OF THE DENTAL PULP 167 by heat, direct sunlight and oxygen. Antibodies or antitoxins canbe prepared against toxins, but not against ptomains. As veryfew bacilli are known that produce specific toxins, it is plain whyso few true antitoxins have been artificially prepared. Again, bacteria may produce poisons within their own cellbodies; they are not usually secreted by the cells, but are alsospecific in their poisonous nature. These bodies are known asendotoxins. As yet no antitoxins have been prepared againstendotoxins, and, as most bacterial diseases are caused by endo-toxins, the preparation of sera has been greatly retarded, andconsequently, immunization against many infectious diseases isapparently impossible. Furthermore, bacteria contain poisonous. Fig. 82.—Smear obtained from suppurating pulp. Mixed infection; 1 : 1000. (Miller.) materials which form an integral part of their protein constitu-ents. These poisonous materials are not soluble, and apparentlydo not produce diseased conditions. The bacterial substancesthemselves may, however, produce inflammation and pus, or evennecrosis, when injected into living tissues. These substances arecalled bacterial proteins. Diagnosis.—In complete necrosis or gangrene of the dental pulpwhen confined to an open root canal usually no painful symptomsare manifested. As soon as disturbances of the periapical tissuesoccur, which were primarily the sequences of pressure from con-fined gasses produced by the decomposition of pulp tissue, markedprogressively increasing pain with all the additional symptoms of 168 DISE iSES OF THE DENTAL li LP an acute inflammation of the pericementum
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