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 moderate‐to‐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.