The longevity of teeth depends directly on the state of the periodontal tissues. Many etiologic factors can lead to the loss of a tooth. Tooth loss is frequently associated with bone resorption. The diagnosis of a condition and knowledge of its etiology are essential to assess the prognosis of the remaining teeth and to formulate the correct treatment plan. Many parameters must be investigated to ascertain an accurate diagnosis. An understanding of the patient's needs and the length and likely success of treatment guides the decision of whether to preserve teeth or extract them and place implants. Advanced periodontitis poses a major therapeutic dilemma. Judicious, strategic extractions may permit the placement of long implants in ideal positions.