The role of dental pulp cells in resorption of deciduous teeth.

OBJECTIVE To address the question whether dental pulp cells of exfoliating human deciduous teeth have some roles for controlling or regulating the root resorption via secreting key molecules (OPG, RANKL, CSF-1, TGFbeta, MCP-1 and Cbfa-1) in osteoclastogenesis, we used a sensitive reverse transcriptase polymerase chain reaction (RT-PCR) method for detection of mRNA expressions for the cytokines listed. STUDY DESIGN The dental pulps were retrieved from incisor and molar teeth in the late stage of shedding (n = 30) and from sound premolar teeth extracted for orthodontic reasons (control group; n = 30). The RT-PCR assays were used to identify targeted gene expression. RESULTS Of the cytokines examined, RANKL and CSF-1 expressions showed significantly higher occurrence in deciduous dental pulps than in permanent teeth pulpal tissues (P < .040). CONCLUSIONS The findings may suggest an interactive role for pulp tissue cells in the physiologic root resorption process. The cells of dental pulp may have some cytokine-producing cells which mediate monocyte-macrophage lineage to form osteo/odontoclasts, and the RANKL/RANK system might be involved in human deciduous teeth resorption.