The study is conducted to evaluate the invitro effect of Salvadora persica (miswak) extract on periodontal fibroblasts production of matrix metalloproteinase-9 (MMP-9) and prostaglandin E2 (PGE2) and correlating the results to clinical outcomes and biomarkers by assessing the MMP-9 and PGE2 levels in gingival crevicular fluid by a randomized controlled clinical trial comparing the use of toothbrush as the control group with miswak chewing stick as a substitute to personal mechanical plaque control in patients with stage II or III grade B periodontitis.