This application was developed to test the following hypothesis: A medical model of periodontal therapy, when compared to a traditional model, is as clinically effective, is more valuable, and can be realistically implemented in clinical practice. To accomplish this task a prospective, blinded, community based, cohort trial will be carried out. Two analytical techniques will be employed to compare the outcomes of periodontal therapy: clinical effectiveness and value. The two primary outcome variables for assessing clinical effectiveness will be clinician centered (attachment level) and patient centered (quality of life). The key outcome variable for value determination is cost of care. Value is then determined by dividing the outcome by the cost of care. Thus a similar outcome at reduced cost increases value. This facilitates calculating cost-effectiveness and cost-utility of care, preparing decision analysis trees, and carrying out sensitivity analysis.