Table 2.

Fluorescein Tracer from the Air-Turbine Handpiece, Collected by Settlement onto Filter Paper Samples in the Open-Plan Setting and Measured Using Fluorometric Analysis.

Experiment	Position (n Samples)	Mean Fluorescence, RFU	SD	% Reduction
Air-turbine handpiece: open-plan setting
No LEV (suction), n = 3	≤0.5 m (27)	10,726	27,367	Reference
	1–2 m (72)	164	338	Reference
	2.5–4 m (96)	66	73	Reference
LEV and suction, n = 3	≤0.5 m (27)	517	1,324	95.2
	1–2 m (72)	51	155	69.0
	2.5–4 m (96)	14	33	78.3

Data for each group adjusted for background fluorescence in the respective location by subtraction of mean negative control values from each sample (≤0.5 m = 41 RFU, 1–2 m = 41 RFU, 2.5–4 m = 39 RFU) before averaging. All experiments also used dental suction.

LEV, local exhaust ventilation; RFU, relative fluorescence units.