Table 1.

Representation of the PICOS of the systematic review

PICOS	Inclusion Criteria	Exclusion Criteria
Population	Studies assessing cultured macrophage cells	Studies assessing cells other than macrophages
Intervention	Studies evaluating the effect of P. gingivalis	Studies evaluating the effect of bacteria other than P. gingivalis
Comparison	Studies evaluating a group of macrophages without exposure to any bacterial species	-
Outcome	Studies assessing the rate of foam cell formation from macrophage cells	-
Study Design	In-vitro studies	Case reports, narrative reviews, systematic reviews with or without meta-analysis, letters to the editors, short communications, in-vivo studies, ex-vivo studies, animal studies, and non-comparative studies.