 INTRODUCTION - When the basic oral hygiene is poor, orthodontic appliances create areas where plaque gets accumulated, especially around brackets, bands, wires, and other attachments; this facilitates the development of white spot lesions. Probiotics act by competitively inhibiting the pathogenic bacteria because they have greater adhesion to the tissues while Chlorhexidine is often used as an active ingredient in mouthwash designed to reduce dental plaque around orthodontic appliances. AIM OBJECTIVE - The objectives of the study is to evaluate and compare the effects of the topical application of probiotic toothpaste and chlorhexidine mouthwash on the Streptococcus Mutans levels in the plaque of orthodontic patients hence improving the oral micro-flora of oral cavity by competitive inhibition of Streptococcus Mutans in plaque present around brackets. 