International Journal of Health Sciences & Research (www.ijhsr.org) 280 Vol.9; Issue: 12; December 2019 International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571 Original Research Article Comparing the Effect of Three Different Fluoride Varnishes on Salivary Fluoride Ions and Streptococcus Mutants' Levels: Clinical Trial Rabab I Salama 1 , Waleed G Taju 2 1 Assistant Professor of Dental Public Health, 2 Assistant Professor of Orthodontic, Department of Preventive Dentistry, Faculty of Dentistry, Umm Al-Qura University, Kingdom of Saudi Arabia Corresponding Author: Rabab I Salama ABSTRACT Background: Fluoride content in saliva and dental plaque plays a key role in the prevention and control of dental caries. Fluoride varnish adheres to the tooth surface for longer period and prevents its immediate loss, thus acting as slow-releasing reservoirs. Aim: to evaluate the effect of different fluoride varnishes forms on the level of fluoride ions in saliva and their antibacterial action on streptococcus mutans. Materials and methods: Seventy five school children of age 12-15 years were selected fulfilling inclusion and exclusion criteria and divided into three groups: Group I (Duraphat varnish); Group II (Bifluorid 10) ; Group III (MI varnish). Salivary samples were collected and fluoride ions were recorded at baseline, one, two, 24,48 hours after applications. Salivary streptococcus mutans (CFUs X 10 6 ) was assessed at baseline and after one, two, three, and four weeks of applications. Results: Statistical significant higher mean values of fluoride ions Group II (Bifluorid 10); Group III (MI varnish) after one, two, 24, 48 hours of applications. Statistical significant reduction was detected in the streptococcus mutans level with the three used varnishes with different levels. Conclusion: After 48hrs of fluoride varnishes application, (MI varnish) fluoride varnish with CPP-ACP was superior to other varnishes to maintain high level of salivary fluoride ions. Fluoride varnish with CPP- ACP and Bifluorid 10 varnishes keep the saliva with low level of cariogenic streptococcus mutans after four weeks of application. Keywords: salivary fluoride ions, streptococcus mutans, fluoride varnishes, MI varnish, Bifluorid varnish INTRODUCTION The prevention of dental caries in children and adolescents is generally regarded as a priority for dental services and considered more cost-effective than its treatment. [1] Fluoride found to be the most effective cariostatic agent in dentistry; the actions of fluoride for caries prevention are related to its effect on cariogenic bacteria, altering the salivary and plaque contents. [2] Fluoride reducing demineralization and improving remineralization of the tooth structure, it can provide antimicrobial effect by reducing bacterial metabolism and interfering in protons extrusion. [3] Studies have shown that high concentrations of fluoride are effective in reducing acid production and acid tolerance as well as extracellular polysaccharide formation of Streptococcus mutans biofilm. [4,5] Recently, Pandit et al., [6] showed that one minute of application of more than or equal 300 ppm fluoride was able to control cariogenic biofilm through inhibition of virulence properties. Fluoride can induce remineralization even with low concentration (0.02 ppm) in saliva and