Mast cells and lymphocyte subsets in pulps from healthy and carious human teeth

To evaluate the presence of cytolytic T lymphocytes (CD8+), memory T cells (CD45RO+), helper T lymphocytes (CD4+), and mast cells in pulps from healthy and carious human teeth.

The teeth were separated into groups: I = unerupted; II = partially erupted, without caries; III = erupted, without caries; IV = erupted with shallow dentine caries; and V = teeth with pulp polyps. The immunoperoxidase staining procedure was used to detect CD8, CD45RO, CD4, and tryptase (mast cell marker) antigens. The number of each cell type was obtained by counting the number of cells per mm2.

Mast cells were only present in pulp polyps. Pulps from carious teeth contained more CD4+ and CD8+ cells than from noncarious teeth. There was a significant decrease in the number of lymphocytes in pulp polyps in comparison to the other groups.

Mast cells probably do not contribute to the early vascular or specific immune responses in the initial dental pulp pathosis, although they may be involved in a chronic phase of pulp inflammation such as pulp polyps. On the other hand, CD4+ and CD8+ T cells participate mainly in initial phenomena of the immune response to incipient caries and seem not to substantially contribute to the response in pulp polyps.