The long-term effectiveness of periodontal therapy in a clinical practice.

A retrospective study was conducted of 620 patients in a periodontal practice over the years 1960 to 1982. Various periodontal therapies were assessed by using careful office protocols, meticulous record-keeping and well-defined outcome criteria. Four treatment outcome categories were used: two representing satisfactory outcomes (referred to as "STABLE"), and two unsatisfactory outcomes ("UNSTABLE"). The percentages of patients in the STABLE categories following different therapies were: (1) nonsurgical treatment, 63.6%; (2) closed curettage, 73.1%; (3) open curettage, 95.0%; (4) modified Widman flap, 91.6%; (5) full flap and osseous surgery, 71.1%. The major conclusions were that the modified Widman flap and open curettage were more effective than flap and osseous surgery, and much more effective than closed curettage when it was employed as an alternative treatment (54.8% STABLE) to the osseous surgery (71.1% STABLE). Thus, moderate surgical therapies appear to be at least as effective as ostectomy procedures in the treatment of periodontal disease, while nonsurgical and closed curettage therapies appear to be less effective.