OR24 - Mechanosensitive Piezo1 and Piezo2 Ion Channels in Dental Inflammation and Pain

Objectives: Dental pain remains one of the most prevalent pain conditions, and is associated with mechanical allodynia and spontaneous pain from increased pressure within the dental pulp. Piezo receptors are essential to mechanosensation and mechanotransduction, and recent research have indicated their presence within the dental pulp. The objectives of this study were to determine potential contributions of the Piezo receptors to dental inflammation and pain by studying the distributions of Piezo-1 and Piezo-2 receptors in symptomatic and asymptomatic pulpitis.

Methods: 45 patients consented to the study and their extracted teeth collected into three groups (n=15/group) based on the clinical diagnosis: normal pulp (NP), symptomatic irreversible pulpitis (SIP), and asymptomatic irreversible pulpitis (AIP). Histological processing followed to determine the histological diagnosis, area of primary injury, and level of inflammation. Immunofluorescent staining were performed for Piezo-1, Piezo-2, and neuronal marker PGP9.5 and imaged by confocal microscopy. Statistical analysis was performed using ANOVA.

Results: Immunofluorescent staining found Piezo-1 and Piezo-2 localized to neuronal structures and odontoblasts throughout the pulp. Semi-quantitative analyses demonstrated statistically significant increases in Piezo-1, Piezo-2, and PGP9.5 expression in SIP compared to NP samples (p < 0.05). All markers were stained the most intensely at the area immediately subjacent to injury and less intensely moving away from the area of injury.

Conclusions: Increased expression of Piezo-1 and Piezo-2 receptors in symptomatic pulpitis suggests their involvement in mechanical allodynia in dental pain. Piezo receptors may be putative targets for emerging anti-nociceptive drugs targeting dental inflammatory pain.