Good prognosis: Control of etiologic factors and adequate periodontal support ensure the tooth will be easy to maintain by the patient and clinician. Fair prognosis: Approximately 25% attachment loss or grade I furcation invasion (location and depth allow proper maintenance with good patient compliance). Poor prognosis: 50% attachment loss, grade II furcation invasion (location and depth make maintenance possible but difficult). Questionable prognosis: >50% attachment loss, poor crown-to-root ratio, poor root form, grade II furcation invasion (location and depth  make  access  difficult)  or  grade  III  furcation  invasion; mobility no. 2 or no. 3; root proximity. Hopeless  prognosis:  Inadequate  attachment  to  maintain  health, comfort, and function. Ref: Newman and Carranza’s Clinical Periodontology, thirteenth edition; page no 413