Dentin hypersensitivity

Aim: This study assessed the activity of neuron/odontoblast receptors and neuropeptide release, under an animal model of dentin hypersensitivity (DH). Methods: Wistar rats were allocated in two groups (n=10): in test group DH was induced by a validated protocol in which a sports drink (pH 3.08) was ingested for 45d, while in control group, the animals ingested filtered water instead. Animals were euthanized and blood samples were collected to measure plasma corticosterone levels. Dental pulp samples (n=6) were processed for Western Blot and ELISA analysis of TRPV1 (mechano-, thermo- and chemoreceptor), P2X7 (adenosine triphosphate (ATP)-mechanosensitive receptor), TRPM8 (cold-sensitive receptor) and substance P (neurogenic peptide released by neuron activation and due to TRPV1 expression). Data were analyzed using Student’s t tests (α=0.05). Results: DH significantly increased expression of TRPV1 (p=0.002), P2X7 (p=0.007) and substance P (p<0.001) but did not significantly affect the activity of TRPM8 (p=0.079). Conclusion: Under DH condition, neurons and odontoblasts expressed TRPV1 and P2X7 receptors as well as increased substance P release, demonstrating cellular and molecular mechanisms underlying DH.