The two most common forms of oral disease, dental caries and periodontal disease, share their main etiologic factor, dental plaque. By specifically targeting their main etiologic factor, bacteria in dental plaque, cause-related therapy allows clinicians and patients to achieve successful control of these diseases. Clinicians should continuously guide and educate patients to understand the pathophysiology of their diseases so that patients will actively participate in the therapy by mechanically removing dental plaque at home. When this is combined with professional intervention (ie, removal of active caries and periodontal mechanical debridement) as well as frequent maintenance therapy, dental caries and periodontal disease can be successfully managed and controlled. This review outlines the steps and components of cause-related therapy as well as its proven long-term clinical benefit. Keywords: dental plaque, gingivitis, nonsurgical periodontal therapy, oral hygiene, periodontitis