Five‐year radiological findings from a randomized controlled trial of four periodontitis treatment strategies

Radiographic findings from long‐term studies of periodontitis treatment have rarely been reported. Although bone destruction is a prominent feature of periodontitis, the long‐term effect on alveolar bone levels of different treatment strategies, with or without adjunctive metronidazole (MTZ), has not been reported. We investigated the 5‐year radiographic outcome of therapy in patient groups treated with conventional scaling and root planing (SRP) or same‐day full‐mouth disinfection (FDIS), with or without adjunctive MTZ. Following a 3‐month oral hygiene phase, 184 periodontitis patients were randomly allocated to one of four treatment regimens: (i) FDIS+MTZ; (ii) FDIS+placebo; (iii) SRP+MTZ; or (iv) SRP+placebo. Following active treatment, patients received biannual maintenance. In total, 161 patients (87.5%) completed the 5‐year follow‐up examination, at which the radiographic bone level (RBL), clinical attachment level, probing pocket depth, presence of plaque, and bleeding were recorded again. At the 5‐year follow up examination, minor radiological bone loss was observed in the intervention groups FDIS+placebo, SRP+MTZ, and SRP+placebo; by contrast, the FDIS+MTZ group did not show any change in RBL. Full‐mouth disinfection did not generally perform better than conventional SRP performed over a period of 2 to 4 weeks.