Influence of different curette insertion depths on the outcome of non-surgical periodontal treatment

This study was undertaken to compare the effects of scaling and root planing (Sc/RP) performed from approximately 1 mm coronal to (test Sc/RP) or at the bottom of (control Sc/RP) the probeable pocket to the gingival margin. 2 male and 5 female patients with moderate to severe periodontitis participated in the study. Initial examination was performed with respect to probing pocket depth (PPD) and probing attachment level (PAL) using a pressure-controlled periodontal probe and stents. The patients received repeated instruction in oral hygiene, and their plaque control reached an excellent level. Baseline examination including PPD and PAL measurements was then performed. Following the baseline examination, single-rooted teeth in 1 quadrant of each dentition were randomly selected and subjected to the test Sc/RP (test teeth) or control Sc/RP (control teeth). The PPD and PAL were measured 1 and 3 months following Sc/RP. It was demonstrated that: (i) the PPD reduction following Sc/RP was larger at the sites with initially deep pockets than at the sites with shallow pockets; (ii) the mean PPD reduction at the sites with an initial PPD greater than or equal to 3.5 mm was significantly larger in the control teeth than in the test teeth; (iii) there was a significant PAL gain in the initially deep pockets but not in the initially shallow pockets; (iv) the PAL gain in the initially shallow pockets was significantly larger in the control teeth than in the test teeth. In the treatment of periodontitis, trauma caused by Sc/RP to the most coronal part of the connective tissue attachment seems to be of minor importance compared to the effective removal of subgingival deposits.