Background.:
The measurement of the concentration of NO in exhaled air is used in the diagnosis and monitoring of treatment of inflammatory processes in the oral cavity and the respiratory tract. An increase of NO level was demonstrated in patients suffering from bronchial asthma and in patients with inflammatory processes in the oral cavity. NO in the exhaled air is a sensitive indicator of the inflammatory process.

Aim of the study.:
To analyse the impact of various oral bacterial flora on the level of NO concentration in the exhaled air of patients using removable complete and partial prosthetic restorations.

Material and methods:
The study was conducted among patients using complete and partial removable dentures. Hard dental tissues were examined with a dental mirror and a probe in artificial lighting. The DMF index for hard tissues was calculated. The gingival sulcus bleeding index GBI was used. Oral hygiene status was assessed on the basis of the plaque retention (PLI) index. The mucosa was examined and classified according to Newton’s classification modified by Spiechowicz. The cleanliness of the prosthesis plate was assessed according to the Budtz-Jørgensen index for the complete upper dentures. The NO concentration was measured with a NIOX MINO device. Microbiological examination of the oral cavity was carried out by taking a swab from the floor of the mouth and examined for microbiology. The study participants were qualified on the basis of a questionnaire on their general health and under underwent a standard dental exam. Only healthy individuals were included in the study.

Results:
The physiological microbiome of the oral cavity and the absence of inflammation of the hard and soft tissues of the oral cavity do not increase the concentration of NO in the exhaled air.

Conclusions:
The measurement of NO concentration in the exhaled air is a beneficial method for diagnosing and monitoring oral inflammatory conditions.