The treatment of periodontal diseases

A randomized, blinded, four-arm, placebo controlled trial.

About the project

Working hypothesis: There is no difference in long term clinical and microbiological outcome between groups of patients treated with scaling and root planing/full dentition disinfection and scaling and root planing with or without use of Metronidazole. The relevance of the project lies in the proper scientific testing of a novel treatment strategy that emphasizes the collaboration between the general practicing dentist and the specialist. Moreover, results and knowledge from basic research (antibiotics, microbiology and biofilms) are transferred to clinical research and explicitly applied in this novel treatment strategy. The project is anticipated to add to the national and international building of competence in periodontology and periodontics, through the understanding of the biofilm’s critical effect on success of treatment strategies in periodontics.


For details on the project see the project description.


Details on the ImageJ plugin developed for the project can be found in the page of this publication.


The project has received a grant from NFR (185120 / v50)


  1. Preus HR, Gjermo P, Baelum V. A critical comment to the practice of article "Analysis and Evaluation" Faveri et al. J Evid Base Dent Pract 2014;14:70-72 The Journal of Evidence-Based Dental Practice; DOI: 10.1016/j.jebdp.2015.03.013

  2. Dahlen G, Preus HR, Baelum V. Methodological issues in the quantification of subgingival microorganisms using the checkerboard technique. J Microbiol Methods. 2015;110C:68-77.

  3. Preus HR, Dahlen G, Gjermo P, Baelum V. Microbiological Observations Following Four Treatment Strategies Among Periodontitis Patients Maintaining A High Standard of Oral Hygiene. A Secondary Analysis of a Randomized Controlled Clinical Trial. J Periodontol. 2015;86(7):856-65

  4. Preus HR, Gjermo P, Baelum V. A randomized, double-masked clinical trial comparing four periodontitis treatment strategies: 5-year tooth loss results. J Periodontol Accepted Aug 16th, 2016. In Press

  5. Dahlen G, Preus HR. Low antibiotic resistance among anaerobic Gram-negative bacteria in periodontitis 5 years following metronidazole therapy. Anaerobe Accepted dec 2016, In Press

  6. Preus HR, Gjermo P, Baelum V. A randomized, double-masked clinical trial comparing four periodontitis treatment strategies: 5-year clinical results. Submitted J Clin Periodontol Nov 2016

  7. Vatne JF, Gjermo P, Sandvik L, Preus HR, Patients’ perception of own efforts versus clinically observed outcomes of non-surgical periodontal therapy in a Norwegian population. An observational study. BMC Oral Health Journal (Accepted 2015)

  8. Preus, Hans Ragnar; Torgersen, Gerald R.; Hansen, Bjørn Frode; Koldsland, Odd Carsten; Aass, Anne Merete; Larheim, Tore Arne & Sandvik, Leiv (2015). A new digital tool for radiographic bone level measurements in longitudinal studies.BMC Oral Health.  ISSN 1472-6831.  15, s 107. doi: doi:10.1186/s12903-015-0092-9

  9. Preus HR, Gjermo P, Scheie AA, Bælum V. The effect of adjunctive metronidazole in different periodontal treatment models on the presence of P. gingivalis and T. forsythia. A randomized, double blinded, four arm, 12 months clinical trial. Acta Odont Scand. In Press, Accepted March 2014
  10. Preus HR, Scheie AA, Bælum V. Combined antibiotics and periodontal therapy. J. Periodontol 2014; 85: 369-371
  11. Preus HR, Sandvik L, Gjermo P. Bælum V. Baseline and change revisited: The effect of smoking on the outcome of periodontal treatment.  Eur J Oral Sci 2014; 1–11 DOI: 10.1111/eos.12111
  12. Preus HR, Gunleiksrud TM, Sandvik L, Gjermo P, Baelum V. A randomized, double blind clinical trial comparing four periodontitis treatment strategies. One-year clinical results. J Periodontol 2013; 84: 1075-1086.
Tags: Treatment modalities, Periodontitis, Biofilm
Published Mar. 10, 2014 1:33 PM - Last modified Jan. 26, 2017 2:36 PM