Mini-surgical approaches in 4 to 7 mm probing depths have been shown to facilitate improved deposit removal as compared to closed instrumentation. At the same time this treatment is less traumatic than more extensive flap reflection for root planing. The purpose of this study was to compare the clinical effects of closed root planing (C/SCRP) to those of root planing augmented by papilla reflection and fiber optic illumination (PR/SCRP) over a 6-month period. Fourteen patients with moderate/advanced adult periodontitis received each therapy in 2 experimental periodontitis sites (PS = greater than or equal to 5 mm probing depth and greater than 5 mm attachment loss) and one non-periodontitis site (NPS = less than or equal to 3 mm probing depth and no recession). Presence of supragingival plaque, bleeding on probing, probing depths, and clinical attachment levels were measured before treatment and 6, 12, and 24 weeks posttreatment. Mean supragingival plaque levels were high and did not vary significantly over the course of the study, but bleeding on probing was significantly reduced in PS following both C/SCRP and PR/SCRP (P less than or equal to 0.0001). Mean probing depths were significantly reduced after 6 months (P less than or equal to 0.01) in NPS-PR/SCRP from 2.8 +/- 0.1 to 2.0 +/- 0.2 mm, in PS-C/SCRP from 5.5 +/- 0.2 to 4.5 +/- 0.4 mm, and in PS-PR/SCRP from 5.8 +/- 0.2 to 3.2 +/- 0.1 mm. In periodontitis sites, PR/SCRP demonstrated greater probing depth reductions than C/SCRP at all time periods (P less than or equal to 0.004). PS attachment levels also improved following C/SCRP and PR/SCRP at all postoperative times (P less than or equal to 0.01). PR/SCRP appears to provide better short-term mean probing depth reduction (2.6 mm) than C/SCRP (1.0 mm), presumably due to apical positioning of the papillae and periodontal repair following improved access for root planing.