Metformin as an adjunct to periodontal treatment


Metformin is widely used for the treatment of type 2 diabetes. It has also been shown to stimulate bone formation consequently it might have a role in the treatment of periodontal bone defects.

 The aim of this review was to evaluate the efficacy of metformin as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis.


Searches were conducted in the Medline, Embase and the Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register. This was supplemented by manual searches of the Journal of Clinical Periodontology, Journal of Periodontology and Journal of Periodontal Research.  Randomised controlled trials (RCTs) in patients with moderate to advanced periodontitis where adjunctive metformin and scaling and root planing (SRP) was compared with placebo and SRP in trials involving more than 10 patients were considered.

Two reviewers independently screened and selected studies extracted data and assessed risk of bias using the Cochrane tool.  The primary outcome was clinical attachment gain with bone depth fill (BD) and reduction in probing depth (PD) as secondary outcomes. The weighted mean differences (WMD) of outcomes and 95% confidence intervals (CI) for each variable were calculated using the random effects model.


  • 5 RCTs involving 256 patients were included.
  • Risk of bias was considered to be high in 2 trials, moderate in 1 and low in 2 trials.
  • All 5 studies reported significantly higher improvements in the metformin + SRP group compared with the control group (SRP + placebo).
  • 3 studies contributed to the meta-analysis
  WMD (95%CI)
Clinical attachment level gain −2.83 (−3.32 to −2.34)
bone depth fill −2.96 (−3.99 to −1.93)
probing depth reduction −3.11 (−3.63 to −2.59)


The authors concluded: –

Adjunctive use of metformin delivery in periodontal treatment appears to be effective in BD fill, reducing probing depth and gain in the clinical attachment level. Further multi-centered RCTs are warranted in future to prove additional benefits of metformin as an adjunct to SRP in the treatment of chronic periodontitis


The reviewers have search three major databases as well as hand searching 3 key periodontal journals. They have also restricted their search to RCTs. The reviewers have only assessed 2 of the included trials as being at high risk of bias although they indicate that they considered 3 of the 5 trials at high risk of bias for allocation concealment. The follow up period for the studies ranged from 24-36 weeks and all 4 out of 5 studies involve some of the same authors. All 3 of the studies contributing to the meta-analysis were conducted by the same group.  So while the findings suggest a benefit the quality of the studies is limited and further high quality studies from a range of research groups and of longer duration are required.


Primary Paper

Akram Z, Vohra F, Javed F. Locally delivered metformin as adjunct to scaling and root planing in the treatment of periodontal defects: A systematic review and meta-analysis. J Periodontal Res. 2018 Jun 2. doi: 10.1111/jre.12573. [Epub ahead of print] Review. PubMed PMID: 29858876.

Original review protocol on PROSPERO

Other references

 Dental Elf – Jul 6th 2018

Statins as an adjunct to periodontal treatment?




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