A Randomized Double-Masked Clinical Trial Comparing Four Periodontitis Treatment Strategies: 5-Year Tooth Loss Results

Background: Tooth loss is the ultimate negative consequence of periodontitis, and reports of the extent to which different treatment strategies may influence long-term tooth loss are hard to find. This study aims to test the hypothesis that there is no difference in 5-year clinical outcome of therapy in terms of tooth mortality between groups of patients treated with conventional scaling and root planing (SRP) over weeks or same-day full-mouth disinfection (FDIS), with or without adjunctive metronidazole (MET). Methods: One hundred eighty-four patients with moderateto-severe periodontitis were randomly allocated to one of four treatment groups: 1) FDIS+ MET; 2) FDIS+ placebo; 3) SRP+MET; and 4) SRP+placebo. Total 161 patients (88%) completed the 5-year follow-up examination, and data on number and timing of tooth extractions as well as pre-extraction diagnoses and reasons for extractions were analyzed. Results: No differences were observed between groups with regard to number of, reasons for, or time of extractions in the four groups at baseline and 1, 3, and 5 years after treatment. Conclusion: If extraction or retention of teeth is regarded as a measure of failure or success 5 years after completion of periodontal therapy, none of the four strategies produced an end result better than the other. J Periodontol 2017; 88:144-152.