Effect of soluble plaque factors on inflammatory reactions in the dental pulp

The present investigation was undertaken to determine whether soluble factors from human dental plaque are capable of inducing or mediating pathological alterations in the dental pulp. The experiment was performed in three monkeys and involved 40 teeth in all: 20 test and 20 control teeth. Class V cavities were prepared on the buccal surface close to the marginal gingiva. In the test cavities an extract of human dental plaque was applied once very 5 min during an 8-h period. The cavities of the contralateral teeth were treated in an identical manner but with Ringer's solution. The animals were sacrificed 10 or 32 h after the initiation of the test. Two hours prior to sacrifice the animals were injected with colloidal carbon and then perfused with 10% neutral buffered formalin. Histologic examination demonstrates that the pulp tissue response to topical application of a plaque extract was characterized by (1) increased degree of carbon retention - indicative of vascular exudation and (2) enhanced rate of emigration of neutrophils and monocytes.