Supplementation With L-ornithine Increases Representation Density of CD68+ and CD163+ Macrophages in Human Periodontitis Gingiva and Can Modulate Macrophages Phenotypes. Randomized Controlled Pilot Trial

Study design The present work was the original research study. 75 individuals with a diagnosis of generalized periodontitis at stages II-III and grade B (38 women and 37 men, 51% and 49%, respectively) were included in the study. Periodontitis was diagnosed by using the criteria of the Classification of Periodontal and Peri-Implant Diseases and Conditions 2017. Stage II of periodontitis was diagnosed in the presence of 3 to 4 mm interdental CAL at the site of greatest loss, 4 to maximum 5 mm PPD, the radiographic bone loss at the root coronal third, and no tooth loss due to periodontitis. Stage III was diagnosed in the presence of ≥5 mm interdental CAL, the radiographic bone loss extending to the middle or apical third of the root, ≤4 teeth loss due to periodontitis. In all cases, periodontitis had a generalized pattern (>30% of teeth involved) and grade B as patterns of the progression, based on indirect evidence (radiographic bone loss expressed as a percentage of root length divided by the age of the subject was from 0.25 to 1.0).

Patients were grouped by stratified randomization into three groups: the SRP Group (patients received scaling and root planing as a full-mouth procedure, n=25); the Arg Group (patients received oral L-arginine aspartate (Yuria-Pharm, Ukraine) at a dose of 1 g t.i.d. for 10 days after SRP, n=25); and the Orn Group (patients received oral L-ornithine aspartate (Farmak, Ukraine) at a dose of 3 g t.i.d. for 15 days after SRP, n=25). We used arginine and ornithine according to instructions for these medicines available for use in Ukraine. During the study, all patients were on a stable diet, without changing their rations and regiments.

For all participants, gender and age were recorded, and periodontal parameters such as periodontal pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BoP) measurements were taken from six periodontal sites on all teeth (except for the third molars) by a single calibrated examiner using a manual periodontal probe (dental explorer tool labeled 0106.DT06.CP10, Den Tag, Italy). PPD and CAL were measured to the nearest 1 mm.

All patients were clinically examined before treatment and after 1 month ± 5 days.

Collection of gingival tissue samples For the precise immunohistochemical study, the gingival biopsy of approximately 3x3 mm was excised under local anesthesia before treatment and 1 month later in 5 selected patients per group. Biopsies were obtained in the same time-points, from a single site displaying the deepest pocket around suitable dental and periodontal procedures. Removal of these tissue biopsies did not interfere with the initial treatment plan or influence upon the expected clinical outcomes. After collection, biopsies were fixed in a 4% formalin solution for 24 hr of fixation, dehydrated, and embedded in paraffin.