Table 1. Search parameters .

Database	Parameters	Filters	Articles retrieved
Sep 10, 2020
PubMed	("decontamination"[MeSH Terms] or "decontamination" [all fields]) or "oral hygiene"[all fields]) or "oral rinse" [all fields]) or "oral decontamination"[all fields]) or "selective oral decontamination"[all fields]) and ("oropharynx"[mesh terms] or "oropharynx"[all fields])) or ("oropharynx"[mesh terms] or "oropharynx"[all fields] or "oropharyngeal"[all fields])) and (vap[all fields] or (("VAP"[all fields] or vap[all fields])	None	580
Embase	('Selective oral decontamination' or (selective and oral and ('decontamination'/exp or decontamination)) or 'oral Decontamination':ti,ab,kw or 'oropharyngeal Decontamination':ti,ab,kw or 'oropharynx Decontamination':ti,ab,kw or 'mouth hygiene':ti,ab,kw) and 'VAP':ti,ab,kw or 'VAP':ti,ab,kw)	None	104
Scopus	(TITLE-ABS-KEY (decontamination) or TITLE-ABS-KEY ("oral hygiene") or TITLE-ABS-KEY ("oral rinse") or TITLE-ABS-KEY ("oral decontamination") or TITLE-ABS-KEY ("selective oral decontamination") and TITLE-ABS-KEY (oropharynx) or TITLE-ABS-KEY (oropharyngeal) and TITLE-ABS-KEY ("VAP") or TITLE-ABS-KEY (VAP))	None	125
Web of science	("Selective oral decontamination") or TOPIC: ("oral hygiene") or TOPIC: ("oral rinse") or TOPIC: ("oral decontamination") and TOPIC: (oropharynx) or TOPIC: (oropharyngeal) and TOPIC: ("VAP") or TOPIC: (VAP)	None	255
Cochrane library	Decontamination 789 #2 "Oral hygiene" 3765 #3 "Oral rinse" 250 #4 "Oral decontamination" 45 #5 "Selective oral decontamination" 8 #6 #1 or #2 or #3 or #4 or #5 4729 #7 Oropharynx 2135 #8 Oropharyngeal 2536 #9 #7 or #8 3941 #10 "VAP" 1341 #11 #6 and #9 and #10 34	None	34