Changing the biofilm of the root canals using a paste of calcium hydroxide

Aim. To evaluate the environmental change of root canal biofilm during primary endodontic treatment under the influence of paste containing calcium hydroxide. Materials and methods. Twenty-nine patients with 68 root canals diagnosed with Chronic Apical Periodontitis were included in the study. Treatment was carried out according to clinical recommendations (treatment regimen) for the diagnosis: "Diseases of periapical tissues", approved by Resolution No. 18 of the Council of the Association of Public Association "Stomatological Association of Russia" of September 30, 2014, updated on August 02, 2018. Biological material of the root canal contents was taken before and after injection of calcium hydroxide paste into the root canal for 14 days. The following methods were used: clinical, microbiological – plate count, gram-positive and gram-negative microorganisms, fungi were determined, and polymerase chain reaction (PCR) was performed at the same time. Statistical analysis of data included description of accounting features, assessment of statistical significance of changes in the studied indicators. The critical level of statistical significance of differences (p) was chosen with a value of p < 0.05. Results. According to the conducted studies, statistical analysis showed statistically significant negative dynamics for all studied microbiological indicators. Conclusions. The obtained data allow us to conclude that preparations containing calcium hydroxide can be used in the treatment of patients diagnosed with chronic apical periodontitis as an intracanalicular drug, because it has a bactericidal effect on a limited area.