Background/Aims : Many dental procedures are considered aerosol-generating-procedures (AGPs), producing saliva-contaminated bioaerosol. The study aims were: (1) to characterize the size, concentration and biological content of particles, and (2) to characterise the microbiome of bioaerosols; generated during routine dental care in an Irish community dental surgery. Methods :  An initial assessment of indoor air quality was carried out using the AirVisual Pro (IQAir) air monitor in seventeen dental surgeries. An average surgery was identified and sampled for 2-weeks during routine dental-care. Continuous real-time aerosol monitoring used a Waveband Integrated Bioaerosol Sensor (WIBS)-4 (Droplet Measurement Technologies), accompanied by a clinical care record. Environmental air sampling was conducted using: (1) a SKC Universal-Deluxe-MTX-pump (SKC Ltd) with filter assembly containing a sterile polyethersulfone membrane; and (2) an AberTrap Mk.3 device with two laser-cut, greased impactor paddles. Ten patients undergoing AGPs gave saliva samples and three air samples were taken: before, during and after the AGP, using a Coriolis®µ (Bertin Instruments) cyclonic sampler. Negative controls and field blanks were incorporated. Samples were processed using a DNeasy PowerSoil Pro Kit (Qiagen) and subject to 16S rRNA gene amplicon sequencing and analysis.  Results : Particle counts from seventeen surgeries showed typical diurnal patterns in carbon dioxide and bioaerosols, correlated to room occupancy and AGPs. This was confirmed by WIBS measurements. Preliminary data from 16S rRNA-based analysis of microbial communities and correlations between physical and biological particle dynamics will be presented. Conclusions:  The impact of clinical activity on diurnal particle dynamics in a dental surgery was determined.