
Background: During scaling and root planing procedure aerosol production has been known as potent source of infection. Thus, the aim of the present study was to evaluate and compare the efficacy of two different mouthwashes containing Chlorhexidine and Essential Oils by using them as pre-procedural rinsing agent in reducing the bacterial load of the aerosol produced by ultrasonic scaler. Methods: 45 subjects, age and gender matched were randomly divided into three groups on the basis of agents used for pre procedural mouth rinsing - Group I: Distilled Water (Control), Group II: Chlorhexidine (CHX), Group III: Essential Oils (EO). The aerosols were collected on three previously prepared and sterilised blood agar plates at three different positions in the operatory. The colony forming units were counted after incubating the plates for 48 hours. Results: At all locations, the mean CFU was highest in Group I followed by Group III and Group II. Conclusion: 0.2 % chlorhexidine was found to be most effective pre procedural mouthwash in reducing the bacterial load in the aerosol produced during ultrasonic scaling followed by essential oil and distilled water.