BackgroundRecently, a composite outcome measure (COM) was proposed to describe the short‐term results of periodontal regenerative treatment. The present retrospective study aimed at evaluating the prognostic value of COM on clinical attachment level (CAL) change over a 4‐year period of supportive periodontal care (SPC).MethodsSeventy‐four intraosseous defects in 59 patients were evaluated at 6 months and 4 years following regenerative treatment. Based on 6‐month CAL change and probing depth (PD), defects were classified as: COM1 (CAL gain ≥3 mm, PD ≤4 mm); COM2 (CAL gain <3 mm, PD ≤4 mm); COM3 (CAL gain ≥3 mm, PD >4 mm); or COM4 (CAL gain <3 mm, PD >4 mm). COM groups were compared for “stability” (i.e., CAL gain, no change in CAL or CAL loss <1 mm) at 4 years. Also, groups were compared for mean change in PD and CAL, need for surgical retreatment, and tooth survival.ResultsAt 4 years, the proportion of stable defects in COM1, COM2, COM3, and COM4 group was 69.2%, 75%, 50%, and 28.6%, respectively, with a substantially higher probability for a defect to show stability for COM1, COM2, and COM3 compared with COM4 (odds ratio 4.6, 9.1, and 2.4, respectively). Although higher prevalence of surgical reinterventions and lower tooth survival were observed in COM4, no significant differences were detected among COM groups.ConclusionsCOM may be of value in predicting CAL change at sites undergoing SPC following periodontal regenerative surgery. Studies on larger cohorts, however, are needed to substantiate the present findings.