RT - Journal of Oral & Facial Pain and Headache ID - 10.11607/jofph.19248 T1 - Vanilloid Receptor 1 Expression in Human Tooth Pulp in Relation to Caries and Pain A1 - C. R. Morgan A1 - Helen D. Rodd A1 - Nick Clayton A1 - John B. Davis A1 - Fiona M. Boissonade K1 - blood vessels; inflammation; pain K1 - tooth pulp; vanilloid receptor 1 YR - 2005 SP - 248 AB -

Aims: To investigate the presence of vanilloid receptor 1 (TRPV1) in human dental pulp and to correlate any expression with caries and pain. Methods: Permanent mandibular first molars were col-lected and categorized as intact or grossly carious. Grossly carious teeth were further categorized as carious asymptomatic or carious painful samples. Coronal pulps were removed and processed for indirect immunofluorescence using antibodies raised against TRPV1 and a neuronal marker, either protein gene product 9.5 or alpha-smooth muscle actin, in conjunction with Ulex europaeus agglutinin 1 lectin to fully label the pulp vasculature. Results: Analysis revealed that TRPV1 labeling was not confined to pulpal nerve fibers. TRPV1 was also consistently expressed within pulp microvasculature. Expression of neuronal TRPV1 was signifi-cantly increased throughout the pulp in grossly carious samples (P < .05). No significant differences were found between carious asymptomatic and carious painful samples. A significant increase in vascular TRPV1 expression was observed in arterioles present in the midcoronal pulp in carious painful compared with carious asymptomatic samples (mean area ± SEM [%] of TRPV1 to vascu-lar labeling; 6.48% ± 4.5% for carious asymptomatic teeth, n = 9; 31.21% ± 9.6% for carious painful teeth, n = 9; P = .02). Conclusion: Expression of TRPV1 in pulpal nerve fibers under-goes marked changes with caries. This may be of relevance in the development of pulpal inflammation, but its relationship to dental pain is still unclear. However, vascular TRPV1 expression does appear to be positively correlated with dental pain, thus providing new insights into symptomatic pulpitis.