OBJECTIVETo isolate Nanobacteria from dental pulp stone and perform culturing and the identification of Nanobacteria.

METHODSFreshly collected 27 dental pulp stones were divided into nine samples. Each sample contained three dental pulp stones. All samples were used for the isolation and culture of Nanobacteria. The shape and the growth characteristics of the cultured bacteria were observed. Nanobacteria were identified by von Kossa staining, immunohistochemical staining and indirect immunofluorescence staining, double staining including Hoechst staining and von Kossa staining.

RESULTSThe characteristics growth and morphology of the bacteria detected in seven samples were similar to Nanobacteria. von Kossa staining, immunohistochemical staining, indirect immunofluorescent staining were positive for Nanobacteria. In double staining method, Hoechst staining of the samples was negative for Nanobacteria, but von Kossa staining was positive. Hoechst staining of the dental pulp cells was positive. No Nanobacteria was found in the other two samples.

CONCLUSIONSThe bacteria isolated from dental pulp stone in this study was similar to Nanobacteria in terms of growth rate, morphology and staining properties. These unusual properties of the bacteria may play an important role in the formation of pulp stone.