Plaque Index (PlI)	The plaque index is a clinical indicator of oral hygiene status that measures the level and rate of microbial plaque formation on the gingival margin of the tooth’s surface. PlI is also used to estimate the potential therapeutic or preventive roles of oral care products [24].
Gingival Index (GI)	The gingival index is a numeric scoring system that assesses inflammation and structural changes in gingival tissue [27].
Pocket Probing Depth (PPD)	The probing depth is the distance between the gingival margin and base of the periodontal pocket, providing one of the most accurate parameters for the clinical diagnosis of periodontal disease [23].
Clinical Attachment Level (CAL)	CAL is measured between the fixed point of the cemento-enamel junction of the tooth and the base of the periodontal pocket. The CAL is one of the most accurate and widely used measures for the clinical diagnosis of periodontal disease [23].
Bleeding on Probing (BOP)	BOP is a reliable indicator of gingival inflammation and refers to the bleeding of gingival tissue upon gentle probing [143].
Gingival crevicular fluid (GCF)	GCF is an inflammatory exudate that permits non-invasive sampling from the oral cavity and is composed of serum, leukocytes, and structural cells from the periodontium and oral bacteria. It is found in the periodontal sulcus between the tooth and marginal gingiva. The GCF flow rate and volume is used as an indicator of gingival inflammation, which can be used to assess periodontal disease severity [25].
Gingival recession (REC)	REC is a clinical measurement of the distance between the cemento-enamel junction and the free gingival margin measured in millimeters (mm) during periodontal probing [26].