Nowadays, an increasing number of dentists support non-invasive methods of treatment of dental discoloration, one of which is the in-office teeth whitening procedure. When treating teeth discoloration and taking into account the aesthetic wishes of the patient, correction of the hygienic state of the oral cavity is important. The study involved 123 people aged 18 to 35 years with sanitized oral cavity and no somatic pathologies. The patients were divided into 3 groups depending on the type of the used whitening system. To assess the hygienic state of the oral cavity, the OHI-S index (GreenVermillion) was used. The presence of the inflammatory process in the periodontal tissues and its intensity was checked using the gingival sulcus bleeding SBI index (MuhlemanSon). The indices were assessed 2 weeks before the office teeth whitening procedure, immediately before it, and 2 weeks, 6 and 12 months after the procedure. Teeth in-office whitening has a positive effect on oral hygiene. Good oral hygiene is noted both in the immediate and long-term follow-up, which is due to the high level of patient motivation. The study of the dynamics of the gingival bleeding index indicates the absence of the adverse effect of in-office teeth whitening on the condition of the periodontal soft tissues.