The aim of this study is to justify the tactics for the restoration of partial tooth crown defects in patients with generalized periodontitis based on the results of a clinical and laboratory research.
As part of the study, 60 patients aged 21–45 years with an equal sex distribution who required replacement of partial tooth crown defects of carious origin (Black Class II), located above or at the level of the gingival margin, were examined and treated. Among the participants, 30 patients had a clinically healthy periodontal tissues; they were included in the first research group. The remaining 30 patients, assigned to the second research group, were diagnosed with chronic generalized periodontitis of stage I–II. In subjects from both research groups, partial defects of the crowns of contralateral teeth were restored, as indicated, with paired restorations: a direct composite restoration on one side and an indirect zirconia restoration, fabricated using CAD/CAM technology, on the other. Clinical and laboratory evaluations were performed prior to treatment and 12 weeks after the restoration of the dental defects.
The control group consisted of 10 volunteers aged 21–25 years with intact dentitions and clinically healthy periodontal tissues. For this group, gingival fluid samples were collected once in the area of the maxillary right first molar.
To clinically evaluate the effectiveness of the treatment provided, the condition of the restorations was assessed after 12 months using modified United States Public Health Service (USPHS) criteria, alongside an index-based assessment of the periodontal status of the abutment teeth.
Sampling and microbiological analysis of the gingival fluid were performed according to established standards using paper strips. The strips were inserted into the gingival sulci to a depth of no more than 1 mm or into the periodontal pockets until resistance was felt and left for 30 seconds. Subsequently, the collected samples were placed in sterile tubes containing 0.2 ml of phosphate-buffered saline and processed ex tempore.
The analysis included the evaluation of the area of the surface soaked with gingival fluid and the mass of the strip, determined by weighing on a torsion balance. To determine the pH of the gingival fluid, universal pH test strips were used, pre-stained blue with a solution of pH 1.0.
According to the statistical processing of clinical and laboratory data, the best prognostic characteristics were established for the bone mineral density (BMD) index calculated from computed tomography data. The sensitivity of this diagnostic method was 78.25 %, specificity was 55.94 %, and the Area Under the Curve (AUC) was 0.744 (P < 0.001). The detection of periodontopathogenic microorganisms in the periodontal pockets also demonstrated high prognostic efficiency: the sensitivity was 56.11 %, specificity was 81.16 %, and AUC was 0.727 (P < 0.001). For the index-based assessment of the clinical state of periodontal tissues, the sensitivity and specificity were 73.11 % and 62.00 %, respectively, with an AUC of 0.735 (Р < 0.001). Thus, according to the grading of AUC values, the prognostic accuracy of these research methods is classified as "good." At the same time, moderate operating characteristics were recorded for the cytokine content in the gingival fluid: sensitivity was 66.90 %, specificity was 70.05 %, and AUC was 0.668 (P < 0.05). The minimum required number of tests, determined by the median value of positive results, was 2 (95 % CI 2–3). The combined use of two research methods ensures the best operating characteristics: sensitivity of 76.54 %, specificity of 73.51 %, and an AUC of 0.800 (95 % CI 0.716–0.880; Р < 0.001).
Therefore, the comprehensive application of clinical and laboratory research methods at the commencement of prosthetic treatment in patients with generalized periodontitis allows for the identification of potential risks and the selection of the optimal dental prosthodontics tactics.
