Appendix 1 Air turbine procedure description including procedure detail, operatory type, duration of procedure and scavenging variation. EOS = extraoral scavenging, HVS = high-volume suction, ES = saliva ejector, RD = rubber dam. Frequency (n) denotes the mean number of times sites within that procedure were contaminated and mean intensity (%) of contamination. Clinician and assistant sites are reported separately

Procedure	Code	Operatory	Duration of procedure	Variation of procedure	Overall frequency of operatory site contamination (n)	Overall mean intensity operatory (%)	Maximum intensity operatory (%)	Maximum intensity operatory site name	Overall frequency of clinician contamination (n)	Overall mean intensity clinician (%)	Maximum intensity clinician (%)	Maximum intensity clinician site	Overall frequency of assistant contamination (n)	Overall mean intensity assistant (%)	Maximum intensity assistant (%)	Maximum intensity assistant site
Occlusal cavity preparation of 36; veneer preparation of 31 and 21 using air turbine handpiece	A1	Closed	20 minutes	HVS and SE	10	1.5	62.64	Patient	7	4.24	51.94	Visor front	2.00	0.22	3.42	Visor front
	A2			EOS, HVS and SE	10	0.61	10.49	Patient	6	2.31	19.11	Left shoe	2.00	0.04	0.53	Left shoe
	A3	Open		HVS and SE	11	9.49	94.12	Patient	6	0.22	1.47	Visor front	4.00	3.20	44.24	Visor front
	A4			EOS, HVS and SE	6	1.7	5.24	Patient	4	0.30	3.55	Visor front	4.00	0.36	4.20	Left forearm
	A5			HVS and SE (short visor)	7	15.87	98.88	Patient	5	0.31	1.82	Chest	6.00	0.39	1.82	Chest
	A6			EOS, HVS and SE (short visor)	6	1.33	3.58	Patient	7	0.40	2.08	Visor front	5.00	0.17	1.67	Right forearm
Labial veneer and palatal access cavity preparation of 21 using air turbine handpiece	B1	Closed	10 minutes	RD, HVS and SE	9	0.34	6.46	Patient	5	1.57	11.48	Chest	3.00	0.15	1.45	Head back
	B2			RD, EOS, HVS and SE	7	0.11	0.99	Site 18	6	0.82	5.49	Visor left	2.00	0.06	0.62	Left shoe
Occlusal cavity preparation of 36 with air turbine handpiece	C1	Closed	5 minutes	HVS	8	3.28	88.8	Patient	6	0.80	4.80	Chest	4.00	0.60	7.01	Right forearm
	C2			EOS and HVS	6	1.91	69.01	Site 24	6	1.38	13.17	Chest	3.00	0.28	3.80	Left forearm
	C3			EOS and SE	4	0.19	4.72	Patient	1	0.06	1.12	Mask	1.00	0.13	2.29	Left forearm
	C4			No suction	10	2.53	56.93	Patient	7	3.24	23.28	Chest	No assistant present
Occlusal cavity preparation of 46 with air turbine handpiece	D1	Open	5 minutes	HVS and SE	3	1.27	2.87	Patient	4	0.12	0.84	Right forearm	3.00	0.11	0.72	Visor front
	D2	Closed		RD, HVS and SE	2	0.03	0.83	Site 18	5	0.34	2.11	Chest	3.00	0.17	2.04	Right forearm
	D3			RD, EOS, HVS and SE	4	0.18	4.29	Patient	4	0.19	1.04	Left forearm	3.00	0.13	0.95	Right forearm