Study On The Correlation Between Putative Periodontopathic Bacteria And Retrograde Pulpitis

Objective To investigate the quantity and proportion of Actinobacillus actinomycetemcomitans (Aa)、Porphyromonas gingivalis (Pg)、Prevotella intermedia (Pi)、Tannerella forsythus(Tf) and Treponema denticola(Td) in subgingival plaque and pulp tissue with retrograde pulpitis; analyze the relationship between the proportions of the five microorganisms and the status of pulp or periodontium; explore the effect of the five microorganisms play in the occurrence and development process of retrograde pulpitis; and provide a scientific basis for the clinical diagnosis and treatment of retrograde pulpitis.Methods Subgingival plaque and pulp tissue were collected from38teeth with retrograde pulpitis, and another subgingival plaque from30healthy teeth as a control. Aa、Pg、Pi、Tf, Td and total bacteria in these samples were assayed respectively using SYBR Green real-time PCR. Calculate the proportions of each microorganism in total bacteria (constituent ratio).Results The detection rate of Aa、Pg、Pi、Tf, Td in the subgingival plaque with retrograde pulpitis is13.2%、76.3%、89.5%、92.1%、92.1% reapectively, and among these microorganisms, Tf(9.01±11.27%) was detected at the highest proportions in total bacteria. Except for Aa, the rest four microorganisms were significantly higher than healthy control group (P<0.05). The detection rate of Aa、Pg、Pi、Tf、Td in the pulp tissue with retrograde pulpitis is respectively0、21.1%、63.2%、81.6%、44.7%, and among these microorganisms, Tf (2.89±4.04%) was detected at the highest proportions in total bacteria.Conclusion Pg、Pi、Tf and Td are closely related to the occurrence and development process of retrograde pulpitis. Among them, the pathogenicity of Pg is remarkable in the periodontium, and Pi、Tf and Td may play a key role in leading to pulp infection. Moreover, the proportion of the five microorganisms in the total bacteria is small, so there may be still other pathogenic microorganisms involved in the occurrence and development process of retrograde pulpitis.