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

J Periodontol. 2017 Feb;88(2):144-152. doi: 10.1902/jop.2016.160332. Epub 2016 Oct 21.


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.

Trial registration: ClinicalTrials.gov NCT01318928.

Keywords: Anti-bacterial agents; dental scaling; metronidazole; periodontal debridement; tooth extraction; tooth loss.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Infective Agents, Local / therapeutic use*
  • Chlorhexidine / therapeutic use*
  • Dental Scaling / methods*
  • Disinfection / methods*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Metronidazole / therapeutic use*
  • Middle Aged
  • Norway / epidemiology
  • Periodontitis / therapy*
  • Root Planing / methods*
  • Tooth Loss / epidemiology*
  • Treatment Outcome


  • Anti-Infective Agents, Local
  • Metronidazole
  • Chlorhexidine

Associated data

  • ClinicalTrials.gov/NCT01318928