The scientific work is devoted to complex study the features of the course of nitrous-oxidative processes, the state of pro-/antioxidant balance and calcium homeostasis of oral fluid, taking into account the age, under conditions of partial and complete teeth loss and in the case of replacement of dental rows defect by dental prosthesis. To achieve the goal, 103 practically healthy people aged from 18 to 89 years were examined, who were divided into groups of observations according to the age criterion (juvenile age – 18-24 years, the period of permanent bite formation; young age – 25-44 years, the period of formed permanent bite; middle age – 45-59 years; advanced age – 60-74 years; senile age – 75-89 years) and dental status (examined with intact dental rows, partial dental rows defects, complete teeth loss and their replacement by various types of dental constructions), and also carried out the dynamic observation during the adaptation to dental prostheses on the 7th, 14th, 30th day after orthopedic treatment. As a result of a study, it was established that the content of hydrogen sulfide in the oral fluid was consistently high in individuals from juvenile to middle age, and had the tendency to decrease with age (decreased by 14.23-15.57 %, p<0.05 in patients of advanced age, by 14.75-24.08 %, p<0.05 – in senile compared to the examined of younger age groups). The content of nitrite ion, the sum of nitrites and nitrates are the lowest at the age of 18-45 years, increasing with age by 57.31 % – in 3.70 times (р<0.05) compared to the values of patients of juvenile and young age. Such changes occurred against the background of suppression of the arginase pathway of L-arginine metabolism, especially in the examined of senile age (the arginase activity decreased by 33.33 %, p<0.05 compared to the values of juvenile age patients). The highest concentration of peroxynitrite was found in the oral fluid of advanced and senile patients, exceeding the value in juvenile individuals by 36.23-47.74 % (р<0.05). Such data characterize the activation of nitrosative processes with age, which significantly increases the risks of dental pathology development. On the 7th day after the replacement of dental rows defects, the content of hydrogen sulfide (by 10.61-57.89 %, p<0.05) and nitric oxide metabolites (by 12.16-41.45 %, p<0.05), OMP (by 51.49 – in 3.13 times, p<0.01) and lipoperoxidation (by 36.36 – in 4.09 times, p<0.05) products in the oral fluid increased against the background of inhibition of antioxidant potential (decrease the activity of antioxidant enzymes by 16.74-53.85 %, p<0.05). On the 14th day, the intensity of nitrous-oxidative stress decreases only under the conditions of CRLP installation. In particular, during the primary orthopedic treatment, the amount of OMP products decreases (by 25.09 %, p<0.05), during repeated – the DC content (by 21.38 %, p<0.05). On the 30th day of the observation, the level of oxidative processes remains high. The OMP products in the oral fluid exceed the initial values during the installation of bridge-like prostheses (BP) by 33.51 % (р<0.05), the primary production of PRLP – by 29.23 % (р<0.05) and CRLP – by 32.09 % (р<0.05). The high level of lipid peroxidation was determined under the conditions of replacement the defects with BP and primary installation of CRLP – the content of DC and TBA-AP exceed the control values, respectively, by 25.77 % (р<0.05), and 27.64 % (р<0.05), and by 93.47 % (p<0.05), and 43.19 % (p<0.05). The activity of examined antioxidant enzymes on the 14th day of observation is decreased by 18.86-57.69 % (р<0.05), but on the 30th day it reaches the control, except the activity of SOD (is decreased under the conditions of repeated orthopedic treatment with CRLP by 22.79 %, p<0.05) and GP (is suppressed by 20.69 %, p<0.05 after the installation of BP). Under such conditions, on the 7th and 14th days, the activity of ALP is decreased (by 21.99-42.53 %, p<0.05) against the background of ACP activation (by 20.30-31.69 %, p<0.05), the acid-base balance is shifted towards acidosis. The hygienic indicators of the mucous membrane of the oral cavity are least affected by the installation of BP. The informative value of peroxynitrite levels in the oral fluid as a predictor of nitrous-oxidative stress in the oral cavity has been confirmed. The diagnostic and prognostic significance of qualitative and quantitative characteristics of hydrogen sulfide in oral fluid for the development of dental pathology and in the mechanisms of adaptation to dental prostheses has been established. Key words: dental status, age groups, mucous membrane of the oral cavity, oral hygiene, complete and partial teeth loss, dental rows defects, orthopedic treatment, dental prostheses, adaptation to dental prostheses, oral fluid, biochemical parameters, gas mediators, nitrous-oxidative stress, antioxidant system, mineralization potential. Branch-Medicine.
