Doxycycline as an adjunct to scaling and root planning in diabetics


The removal and control of the plaque biofilm is the key aim of periodontal treatment. Scaling and root planning mechanically removes plaque, calculus and diseased cementum and a number of adjuncts including a variety of antibiotics have been used in order to improve outcomes.

The aim of this review was to compare the effectiveness of systemic doxycycline as an adjunct to scaling and root planning (SRP) with SRP alone in diabetic patients with periodontitis.


Searches were conducted in the Medline and Scopus databases. Randomised controlled trials (RCTs) in patients diagnosed with periodontitis and diabetes mellitus comparing the effectiveness of systemic doxycycline as an adjunct to scaling and root planing (SRP) published in English were considered.  Two reviewers independently screed the studies, extracted data and assessed risk of bias using the Cochrane tool. Weighted standard mean differences (SMD) and 95% confidence intervals were calculated, and random effects meta-analysis conducted. Overal certainty of evidence was evaluated by Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.


  • 6 RCTs were included
  • 2 studies were considered to be at high risk of bias and 4 at unclear risk.
  • For 3 months follow up a total of 276 patients were included.
  • Meta-analysis (6 studies) at 3 months follow up showed no statistically significant improvement in :-
    • Clinical attachment level (CAL), SMD = -0.22 (95%CI; -0.52 to 0.08) and
    • HbA1c levels at 3 months, SMD =  – 0.13 (95%CI; − 0.41 to 0.15)
    • Probing depth (PD), SMD =  -0.16 (95%CI;  -0.50,  to 0.18)
    • Bleeding on probing (BOP),  SMD =  -0.27 (95%CI;  − 0.80 to 0.27)
  • when systemic doxycycline is used as an adjunct to scaling and root planing compared to just SRP alone.


The authors concluded: –

Systemic doxycycline when used in addition to scaling and root planing yields no significant improvement of clinical attachment levels for periodontal status and reduction of HbA1c levels in treatment of diabetic patients with periodontitis when comparing the test group to the control group.


While this review’s protocol has been registered on the PROSPERO database only two databases have been searched and only English language publications have been included. As a result, it is likely that relevant studies will have been excluded. The impact of treatment for periodontitis on diabetic management one that has been the subject of a larger number of systematic reviews including a Cochrane review which was last updated in 2015.  We recently looked another broader review by Cao et al (Dental Elf – 16th Aug 2019) of SRP and adjuvants in diabetics. They searched 4 databases and only included 3 of the 6 studies included in this new review.  All of the 6 trials included in this review are small in size and none of them were considered to be at low risk of bias so while the reviewers rated the certainty of the evidence at moderate for changes in CAL and HbA1c levels at 3 months this seems like a generous assessment.

The 2015 Cochrane review found only low-quality evidence that the treatment of periodontal disease by SRP improved glycaemic control in people with diabetes and that was no evidence to support that one periodontal therapy was more effective than another.  Rather than additional reviews of this area what is needed is larger, well-conducted and clearly reported primary studies to provide a better evidence-base.


Primary Paper

Yap KCH, Pulikkotil SJ. Systemic doxycycline as an adjunct to scaling and root planing in diabetic patients with periodontitis: a systematic review and meta-analysis. BMC Oral Health. 2019 Sep 5;19(1):209. doi:10.1186/s12903-019-0873-7. PubMed PMID: 31488125; PubMed Central PMCID:PMC6728970.

Review protocol on PROSPERO

Other references

Dental Elf – 16th Aug 2019

Periodontal treatment and glycaemic control in diabetes

Dental Elf – 20th Sep 2017

Nonsurgical periodontal treatment: adjunctive antibiotic use in diabetics

Dental Elf – 9th Aug 2017

Scaling and root planing adjuncts for chronic periodontitis




Share on Facebook Tweet this on Twitter Share on LinkedIn Share on Google+