A histologic study of experimentally induced periapical inflammation in primary teeth in monkeys

Abstract

Periapical inflammation was induced in monkey primary teeth by removing the pulp tissue and leaving the root canals open to the oral cavity for up to 360 days. Fifty-two experimental teeth and a similar number of contralateral control teeth from six monkeys were used. Periapical inflammation developed in 45 teeth, Eighteen of the teeth had abscesses, granulomas and cysts without communication to the oral cavity. Thirty-one fistulae developed from the periapical area of 27 teeth. Pathologic changes in the interradicular areas were seen only in relation to periapical inflammation. Root resorption had, however, taken place in all teeth adjacent to the inflammatory process. When the dentinal tubules ended in a vital periodontal membrane, bacteria were found only in the inner third of the dentinal tubules. In cases where the tubules ended in necrotic periodontal tissues, bacteria could be observed along the entire length of the dentinal tubules. Incorporation of 3H-thymidine in epithelial cells of the periodontal membrane in connection with periapical inflammation was observed regularly. On the basis of the study, a restrictive attitude towards endodontic treatment of primary teeth with a necrotic pulp is suggested.