Table 2 Mean and standard deviation (StD) of the fraction of particles smaller than 100 nm (F< 100) and total number concentration for the dental sprays under investigation
Sprays | F< 100 | Total number concentration | |
|---|---|---|---|
Mean (%) | StD (%) | ||
Mean background concentration |  |  | (780 ± 580) cm−3 |
Spray A | 83.0 | 1.6 | (5.3 ± 1.0) * 105 cm− 3 |
Spray B | 73.2 | 1.1 | (3.3 ± 0.4) * 105 cm− 3 |
Spray C | 93.1 | 2.8 | (5.0 ± 0.5) * 105 cm− 3 |
Spray D | 15.6 | 15.0 | (1.3 ± 0.5) * 105 cm− 3 |
 - Propellant D alone | 100.0 | 0.0 | (0.3 ± 0.2) * 105 cm− 3 |
Spray E | 9.0 | 6.9 | (2500 ± 900) cm− 3 |