Vasodilatation of human gingiva and neurogenic inflammation

BACKGROUND: Neurogenic Inflammation (NI) is the consequence of amyelinic-sensitive neuron activation. Recent studies on rats proved that NI could be experimentally induced by topical capsaicin application. The aim of this study is to evaluate the effects of topical capsaicin application on human periodontal mucosa and to assess if NI might have a role in the pathogenesis of periodontal diseases. METHODS: 15 patients were examined in our laboratory. NI was experimentally induced in the gingival mucosa close to: (1) the interdental papilla corresponding to the upper central incisors; (2) the interdental papilla corresponding to the lower left lateral incisor and canine after ipsilateral nerve trunk anaesthesia. The characteristics of gingival microcirculation were observed using computerised videocapillaroscopic techniques. RESULTS: axon-reflected vasodilatation was observed close to the papilla corresponding to the upper central incisors. An important correlation was observed between capsaicin application and capillary tortuosity. No significant modifications in vascular diameter and tortuosity were observed after capsaicin application close to the interdental papilla corresponding to the lower left lateral incisor and canine. CONCLUSIONS: the study shows that NI can be induced in human gingiva, and such evidence could be extremely important in the pathogenesis and treatment of periodontal diseases