DYNAMICS OF THE LEVEL OF PRO- AND ANTI-INFLAMMATORY CYTOKINES IN THE CREVICULAR FLUID AFTER DIRECT AND INDIRECT RESTORATION

Abstract

The restoration of discolored teeth is conducted by direct and indirect restoration techniques. Impairment of marginal periodontium is possible during the stages of both direct and indirect restoration in gum retraction, cofferdam application, grinding and polishing for direct restoration, removal of fixation cement residues near indirect restorations and finishing preparation of the connection boundary with the tooth. Furthermore, the restorations affect the periodontal tissues in the long term due to the formation of biofilm and dental plaque in the precervical area of the abutment teeth.
 One of the earliest ways to detect the inflammatory process in the marginal periodontium is to determine the level of pro-inflammatory and anti-inflammatory cytokines in the crevicular fluid.
 The aim of the research was to study the level of pro-inflammatory and anti-inflammatory cytokines in the crevicular fluid after direct and indirect restorations, which were performed by classical fixation and via the proposed method of fixation on the heated composite in 24 hours and 12 months.
 Materials and methods of the research. For clinical substantiation and comparison of direct and indirect ceramic restorations with classical fixation and the proposed method of fixation on the heated composite, we examined and collected the material in 24 hours and 12 months after treatment in 84 patients, aged 18-65, with dental discoloration and defects of the crown of the frontal teeth.
 All patients were divided into 7 clinical groups with 12 patients in each. Group 1 was a control, which included patients with intact dentition, without discoloration and defects of the hard tissues of the teeth of the frontal area; group 2 embraced patients who were treated by direct restoration (a day after treatment); group 3 comprised patients, treated with indirect ceramic restorations, which were fixed by conventional methods on a double-cured composite (one day after treatment); group 4 included patients, whose veneers were fixed to the heated composite (one day after treatment); group 5 embraced patients 12 months after treatment with direct restorations; group 6 included patients, treated with indirect ceramic restorations, which were fixed by conventional methods on a double-cured composite (12 months after treatment); group 7 comprised patients, whose veneers were fixed to the heated composite (12 months after treatment). The material for the study was the crevicular fluid. We determined the tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 10 (IL-10).
 The study showed that in all three study groups in 24 hours, the significant predominance of the IL-6 content as compared to the control group was observed. The presence of IL-6 in the crevicular fluid indicates inflammation in the periodontium. The level of another pro-inflammatory cytokine, TNF-α, was higher in the groups with direct and indirect restorations, which were fixed by conventional methods to the composite of double hardening, which relates to adverse factors, since this mediator activates the processes of osteoresorption and enhances inflammatory reactions in the periodontal tissues. When comparing the concentrations of pro-inflammatory cytokines TNF-α and IL-6 in the crevicular fluid between the direct and indirect restoration group, we detected their significantly lower level in the groups where indirect restorations were performed, fixed on the composite cement and on the heated composite. The concentration of IL-10 in the groups with direct and indirect restoration, fixed on the heated composite, was the same, and in the group with indirect restoration, fixed on the composite cement, it increased significantly. After 12 months, the level of pro-inflammatory cytokines TNF-α and IL-6 was significantly higher in the direct restoration group as compared to the indirect restoration groups and with fixation on the composite cement and on the heated composite. The absence of significant differences in pro-inflammatory cytokines in this period for the groups of indirect restorations indicates the absence of inflammatory phenomena in the marginal periodontium and proves the possibility of applying the method of veneer fixation on the heated composite.