Table 4.

Current OMFS literature and guidelines on the surgical mask or respirator use During the COVID-19 pandemic

		NonAerosol-Generating Medical Procedures (non-AGMP)		Aerosol-Generating Medical Procedures (AGMP)		USA Mask/Respirator Levels	European Mask/Respirator Levels
COVID-19 Negative		Standard PPE			✓✓ 13,14	PAPR/CAPR15 Use HEPA or ULPA filters Filtration efficiency: •$\ge$ 99.97% @ 0.3 micron	PAPR/CAPR16 Use HEPA or ULPA filters Filtration efficiency: •≥ 99.95% @ 0.3 micron
					✓ 17
Unknown COVID-19 status	No symptoms - or - Infection unlikely		✓✓ 18,19 (no valve, with overlying surgical mask or visor)		✓✓ 14,20	N10021 Filtration efficiency: •≥ 99.97% @ 0.3 micron		RESPIRATORS
			✓✓✓✓✓✓✓ 18, ∗ 17 [6/12 (50%) sources recommend FFP2 mask or equivalent]		✓✓✓ 19 (withouta valve and with overlying surgical mask or visor),18,20	N9921 Filtration efficiency: •≥ 99% @ 0.3 micron	FFP322 Filtration efficiency: •≥ 99% @ 0.3 micron
			✓ 23(outpatient exam)		✓✓✓✓✓✓✓✓✓✓✓✓ 24,25 (if “risk of exposure is high”), 18,∗ 17 [8/12 (67%) sources recommend FFP2 mask or equivalent (change after each patient)], 20 (if PAPR or FFP3 not available)	N9521 Filtration efficiency: •≥ 95% @ 0.3 micron	FFP222 Filtration efficiency: •≥ 94% @ 0.3 micron
			✓✓✓✓✓ 17,19,24,25 (exam only),23 (outpatient exam)		✓ 25		FFP122 Filtration efficiency: •$\ge$ 80% @ 0.3 microns
	Symptoms - or -Infection likely		✓ 18		✓✓✓ 14,17,20	ASTM Level 326 Filtration efficiency: •BFE ≥ 98% @ 3 microns •PFE ≥ 98% @ 0.1 micron High fluid resistance: 160 mmHg	Type IIR27 Filtration efficiency: •BFE ≥ 98% @ 3 microns	MASKS
			✓✓ 23 (outpatient clinical exam),18		✓✓ 18,20	ASTM Level 226 Filtration efficiency: •BFE ≥ 98% @ 3 microns •PFE ≥ 98% @ 0.1 micron Mod. fluid resistance: 160 mmHg	Type II27 Filtration efficiency: •BFE ≥ 98% @ 3 microns
			✓✓✓ 17,24,25		✓✓✓✓✓✓✓ 18,20,24 (if does not have PAPR or FFP3),28 (if PAPR not available),17 (N95 with surgical mask over it if PAPR unavailable),25 (consider Hazmat suit if the risk of exposure is high),29
COVID-19 Positive			✓ 18		✓✓ 14,17	ASTM Level 126 Filtration efficiency: •BFE ≥ 95% @ 3 microns •PFE ≥ 95% @ 0.1 micron Low fluid resistance: 80 mmHg	Type I27 Filtration efficiency: •BFE ≥ 95% @ 3 microns
			✓✓✓✓✓✓✓✓✓✓✓✓ 23,24 (inpatient exam room with patient contact, or outpatient exam), 18, ∗ 17 [9/12 (75%) sources recommend use of FFP2 mask or equivalent]		✓✓✓✓ 23(In the patient room/exam room/negative pressure operating room), ∗17 [3/12 (25%) sources suggest the use of FFP3 masks or equivalent if available.]
			✓ 23 (inpatient exam room without patient contact)		✓✓✓✓✓✓✓✓✓✓✓✓ 17 (with a surgical mask over it), ∗ 17 [10/12 (83%) sources recommend the use of an FFP2 mask or equivalent (changed after each patient)], 18	Low performance26 Physical barrier only
			✓✓ 17,23 (inpatient exam room without patient contact)		✓✓✓ 18,24,29

Note: medical masks and surgical masks are the same in this table; AGMPs were described slightly differently in each paper, but generally involve operating room procedures or the use of drills or ultrasonic instruments.

Abbreviations: AGMP, aerosol-generating medical procedure; ASTM, American Society for Testing and Materials; BFE, bacterial filtration efficiency; CAPR, controlled air-purifying respirator; PAPR, powered air-purifying respirator; PFE, particle filtration efficiency.

✓ = tally of references recommending each type of PPE.

(PAPR/CAPR³¹) (N100³²) (N99/FFP3³²) (N95/FFP2³²) (FFP1³²) (FFP1³³).

^∗Cochrane review of the national recommendations for the re-structuring and reopening of dental services from 11 countries with 12 guidance documents (produced between March 18 and May 5, 2020).³⁰