Changes in mucosal immunity of oral cavity upon tooth loss in patients with periodontal diseases

Partial or complete loss of teeth occurs in elderly and senile people, caused, mainly, by chronic generalized periodontitis. At the same time, the impact of presence or absence of persisting teeth and periodontium, is practically not covered in the literature as a factor of balance in the oral cavity, including local immunity of the mucous membranes. Our work concerned the changes in local immunity of the oral cavity occuring with the loss of natural teeth. We have observed 45 elderly people who were divided into 3 study groups, i.e., without inflammatory periodontal pathology (1), with periodontitis (2) and with chronic periapical inflammatory processes in the absence of periodontal inflammation (3). In order to sanitize oral cavity before the upcoming dental prosthetics, the patients of study groups 2 and 3 underwent extraction of all teeth in the upper and lower jaws. Indices of local immunity of the oral cavity in the salivary fluid of patients were assessed before surgical sanitation of the oral cavity (before the teeth extraction) and 30-35 days after removal of the last tooth. We have measured the salivary levels of secretory immunoglobulin A (sIgA) as well as pro-inflammatory cytokines, i.e., interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor- (TNF), and anti-inflammatory cytokines, e.g., receptor antagonist of interleukin-1 (RAIL), interleukin-4 (IL-4), interleukin-10 (IL-10)), as well as contents of antimicrobial peptides in saliva (catelicidin LL-37 and alphadefensins 1-3 (HNP1-3). We have found that the development of inflammation in severe inflammatory periodontal diseases, in particular, chronic generalized periodontitis requiring tooth extraction for oral cavity sanitation is characterized by functional insufficiency of secretory immunity of the oral mucosa associated with decreased secretion of secretory immunoglobulin A and antimicrobial peptides of neutrophilic origin, as well as a shift in the salivary cytokine balance towards increased production of pro-inflammatory cytokines. Removal of teeth, as the main source of inflammation and the basis for maintenance of dysbiotic microbiome biofilm leads to elimination of inflammation and the restoration of immune balance in the oral cavity.