Immature DCs are therefore considered to be part of the innate phase of pulpal immune response.Persistent infection leads to the activation of adaptive immunity. A transition to an adaptive immune response will take place in the dental pulp as the caries and bacteria approach the pulp. Antigens are recognized individually and lines of lymphocytes are developed to produce specific antibodies which attach to the recognized cells and initiate their destruction. Phagocytes remove the remains. B cells and T cells are the major lymphocytes involved.A variety of cytokines have been observed in the pulp. Patients with symptomatic and asymptomatic irreversible pulpitis have been shown to have an almost 23-fold increase in the cytokine IL-8 in the pulp. Cytokines in the pulp interact with each other. The ultimate effect on pulpal inflammation and healing is dependent upon the integrated actions of these inflammatory mediators.In addition to the lymphocytes, macrophages also provide defense against certain intracellular pathogens. Activated macrophages can function as class II antigen-presenting cells, similar to pulpal dendritic and B cells. In addition, activated macrophages secrete many inflammatory mediators.Macrophages in the pulp become activated after receiving two signals. The first is a priming stimulus and the second is an activating signal. The priming stimulus is secreted by activated T-helper cells. The activating stimulus may include bacterial lipopolysaccharides, muramyl dipeptide, and other chemical mediators.Macrophages are professional phagocytes in innate immune responses.
There are 3 general types:

Thermal: Agents are applied to increase or decrease the temperature of a tooth and stimulate a pulp sensory response.Cold tests: Most commonly, ethyl chloride is sprayed onto a small ball of cotton wool and is applied to the tooth, which produces intense cold. Alternatively, CO2 snow and other refrigerants such as dichlorodifluoromethane (DDM) have been shown to be effective. Heat tests: Gutta percha can be heated and directly applied to the tooth to produce heat. Electrical pulp test: Electric pulp testing (EPT) has been available for over a century and is used by dentists worldwide. It is used to determine the health of the pulp and pulp-related pain.EPT is based on the stimulation of sensory nerves in the pulp. It does not provide information on vascular supply to the pulp. The probe tip of the test device is placed directly onto the tooth surface and an electrical stimulus is produced. This stimulus causes an ionic change across the neural membrane, inducing an action potential in the myelinated nerves. The threshold of pain is determined by increasing the voltage. A tingling sensation is felt once the voltage reaches the pain threshold. This threshold level varies between patients, and is affected by factors such as age, pain perception, tooth surface conduction and resistance. The requirements of an EPT are appropriate application method, careful interpretation of the results, and an appropriate stimulus. EPT must be done with tooth isolation and conduction media.