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, 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.

  2. Preus HR, Scheie AA, Bælum V. Combined antibiotics and periodontal therapy. J. Periodontol 2014; 85: 374-384.

  3. 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;122:89-99

  4. 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. J Evid Base Dent Pract 2015;15:85-86

  5. 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 Odontol Scand, 2015; 74:258-266

  6. Vatne JF, Mehlum Gunleiksrud T, Gjermo P, Sandvik L, Preus HR.  Perception of own efforts; Patient centered - vs. clinically observed outcomes of non-surgical periodontal therapy in a Norwegian population. BMC Oral Health (2015) 15:61 DOI 10.1186/s12903-015-0037-3

  7. Preus HR, Torgersen GR, Hansen BF, Koldsland OC, Aass AM, Larheim TA, Sandvik L, A new digital tool for radiographic bone level measurements in longitudinal studies. Journal: BMC Oral Health.2015, 15:107. DOI: 10.1186/s12903-015-0092-9

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

  9. 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

  10. Preus HR, Gjermo P, Baelum V. A randomized, double-masked clinical trial comparing four periodontitis treatment strategies: 5-year tooth loss results. J Periodontol. 2017; 88:144-152. doi: 10.1902/jop.2016.160332.

  11. Dahlen G, Preus HR. Low antibiotic resistance among anaerobic Gram-negative bacteria in periodontitis 5 years following metronidazole therapy. Anaerobe. 2017 43: 94-98.

  12. Preus HR, Gjermo P, Baelum V. A randomized, double-masked clinical trial comparing four periodontitis treatment strategies: 5-year clinical results. J Clin Periodontol. 2017 Oct;44(10):1029-1038

Tags: Biofilm, Periodontitis, Treatment modalities
Published Mar. 10, 2014 1:33 PM - Last modified Mar. 6, 2019 11:44 AM