Objectives: Air pollutants in dentistry offices may cause problems for the health of staff and patients. Accordingly, the present study was performed to the assessment of bacterial bioaerosols and particulate matter (PM) characteristics in the indoor air of dentistry clinics.Methods: The sampling points were restoration, endodontics, and prosthesis wards. The PM specimens were taken using Grimm Dust Monitor and the microbial specimens were taken using QuickTake 30.Results: The maximum and minimum PM10 concentration across the different measure wards occurred as 70.31 and 30.32 μg/m3 in the Ketabchi Clinic restoration and its endodontics ward, respectively. The total number of bioaerosols was 2079. Gram‑positive Staphylococcus spp.(872), Gram‑positive Micrococcus spp.(706), and Gram‑negative Bacillus spp.(501) were present in the indoor air. The results showed a significant relationship for PM1 and PM2.5 in each sampling site.Conclusions: The low PM and bacterial bioaerosols contamination can be due to the coincidence with coronavirus pandemic, as during this period, health and hygienic protocols have been strictly observed
