Table 1.

Search strategy.

DATABASE	WEBSITE	SEARCH STRATEGY	TOTAL
Medline/PUBMED via National Library of Medicine	http://www.ncbi.nlm.nih.gov/pubmed	(((((((Periodontal Diseases [mh]) OR (Periodontal Diseases)) OR (Periodontal Diseases [tiab])) OR (periodontitis)) OR (periodont*)) OR (((((gingivitis [mh]) OR (gingivitis)) OR (gingivitis [tiab])) OR (gingivitis)) OR (gingivitis*))) OR ((((((tooth loss [mh]) OR (tooth loss)) OR (tooth loss [tiab])) OR (tooth loss)) OR (tooth loss*)))) AND (((((((Stomach Neoplasms [mesh]) OR (Stomach Neoplasms)) OR (stomach cancer)) OR (gastric adenocarcinoma)) OR (adenocarcinoma [tiab])) OR (gastric cancer)))	353
Embase	www.embase.com	('periodontal disease' OR gingivitis OR periodontitis OR 'tooth loss') AND 'gastric cancer'	74
Scopus	www.scopus.com	(TITLE-ABS-KEY (periodontal AND disease) OR TITLE-ABS-KEY (periodontitis) OR TITLE-ABS-KEY (gingivitis) OR TITLE-ABS-KEY (tooth AND loss) AND TITLE-ABS-KEY (gastric AND cancer))	137
Lilacs	https://lilacs.bvsalud.org/	"(periodontal diseases OR periodontitis OR gingivitis OR tooth loss) AND (stomach neoplasms OR gastric cancer)"	0
Web of science	www.webofknowledge.com	TI=(cancer) AND TS=(periodontal* diseases OR gingivitis OR periodontitis OR tooth* loss AND gastric cancer*) AND AB=(stomach cancer OR gastric cancer AND periodontal disease OR gingivitis OR periodontitis OR tooth loss) AND TI=(stomach cancer OR gastric cancer AND periodontal disease OR gingivitis OR periodontitis OR tooth loss)	75
OpenGrey	http://www.opengrey.eu	"periodontal disease" OR “gingivitis” OR “periodontitis” OR “tooth loss” AND "gastric"	0