Periodontitis is one of the most prevalent diseases affecting nearly one third of the adult population. It is characterized by loss of connective tissue attachment to the tooth and pathological migration of the junctional epithelium apically, which leads to pocket formation, tooth mobility, and finally loss of tooth. There is enough evidence supporting the microbial etiology of periodontal diseaseLocal antimicrobial therapy in periodontitis involves direct placement of an antimicrobial agent(s) into subgingival sites, minimizing the impact of the agent(s) on non-oral body sites. The decision of the local drug delivery during active treatment or maintenance should be based on clinical findings, responses to therapy, desired clinical outcome and the patient's medical history. Success of any drug delivery system depends upon its ability to deliver the antimicrobial agents to the base of the pocket at a bacteriostatic or bactericidal concentration. This book addresses the principle of local delivery of antibacterial agents and their clinical applications in dentistry.