Periodontal diseases are a group of infectious/inflammatory diseases of tooth supporting tissues initiated by putatively virulent microorganisms in the microbial dental plaque.¹ Periodontal tissue destruction derives from a direct effect of the bacterial toxic substances and from the action of the immune system activated by the bacterial infection.² For an accurate diagnosis and a treatment choice, a reliable evaluation of periodontal inflammation is important.

The peptidylarginine deiminases (PADs) are a family of enzymes capable of converting amino acid arginine into citrulline a process known as citrullination.⁴ Citrullination is related to various physiological processes such as skin keratinization and gene regulation for immune functions, and also plays role in autoimmune diseases and inflammatory conditions.^4.5   Antibodies produced against citrullinated proteins are called anti-citrullinated protein antibodies (ACPAs).⁵  It has been hypothesized that periodontitis may be a stimulator for ACPA formation.⁶ In addition, in vitro studies have shown that one of the periodontal pathogens, Porphyromonas gingivalis, produces a variant of PAD (sometimes referred to as P. gingivalis PAD or PPAD), which is capable of citrullinating proteins.⁷ Studies have reported that increased expression of PAD2 in gingival connective tissue of patients with periodontitis compared to periodontal healthy group.⁸ Therefore peptidylarginine deiminases can be used as a biomarker for the evaluation of periodontal disease.

This study is aimed at comparing levels of PAD2 in gingival crevicular fluid of chronic periodontitis patients with before and after scaling and rootplaning alone and as an adjunct to scaling and root planing and flap surgery.