Periodontal treatment and glycaemic control in diabetes


Around 8% of adults over the age of 18 are estimated to have diabetes mellitus and this is expected to increase significantly over the coming decades. Periodontitis is one of the worlds commonest disease with over 50% of adults being affected. Previous reviews have found low quality evidence that periodontal treatment can improve glycaemic control in diabetics.

The aim of this review was to evaluate the efficacy of scaling and root planning (SRP) and SRP + adjuvant treatments in improving glycaemic control in patients with type 2 diabetes mellitus and chronic periodontitis.


Searches were conducted in the Pubmed, Embase, Cochrane Library and Web of Science databases. Randomised controlled trials in adults aged ≥30 years with periodontitis and type 2 diabetes mellitus (T2DM) comparing scaling and root planning (SRP) with no treatment or SRP with adjuvant treatment or SRP and different adjuvant therapies with at least 3 months follow up were considered.  Only studies published in English reporting HbA1C% and fasting blood glucose (FBG) were considered.

Two reviewers independently screened and selected studies, extracted data and assessed risk of bias using the Cochrane domain based tool.  The blinding of outcome assessment was not assessed as for risk of bias as HbA1C% and FBG were considered objective indicators. Random-effects meta-analysis and Bayesian network meta-analysis were conducted.


  • 14 RCTs involving a total of 629 patients were considered.
  • 1 study was considered to be at low risk of bias, 5 at unclear risk and 8 at high risk.
  • Traditional meta-analysis showed additional benefits for reduction in HbA1c% compared to SRP alone compared with SRP + laser(aPDT) = 0.19 (0.08, 0.30) and for SRP + antibiotic compared to no treatment M= 0.82 (0.33, 1.31). No other differences were found.
  • The network meta-analysis showed that SRP + antibiotic =0.61(0.16, 1.1), SRP + aPDT + Doxy (doxycycline) =1.1 (0.11, 2.1), SRP + laser =0.66 (0.097, 1.3) and SRP alone = 0.40(0.086, 0.80) was significantly better than no treatment in improving HbA1c%.
  • The probabilities the most effective treatment methods of decreasing HbA1c% was SRP+ aPDT + Doxy (71.2%), followed by SRP + laser (13.6%), SRP + SDD (8.6%), SRP + antibiotic (3.8%), SRP (0.2%).


 The authors concluded: –

The results of this meta-analysis seem to support that periodontal treatment with aPDT + Doxy possesses the best efficacy in lowering HbA1c% of non-smoking CP without severe T2DM complications. However, longer-term well-executed, multi-centre trails are required to corroborate the results.


This new review of non-surgical periodontal treatment and its effect on glycaemic control in type 2 diabetics has chosen to restrict the inclusion criteria to publication in English and also to adults over the age of 30 this places some obvious limitations on the findings of the review. The 2015 Cochrane review (Dental Elf – 11th Nov 2015) looked at adults over 18 so included many more studies (35) than this current review finding low quality evidence that the treatment of periodontal disease by SRP did improve glycaemic control in people with diabetes with a  mean percentage reduction in HbA1c of 0.29% at 3‐4 months.

While this current review suggests that adjunctive treatments may provide some additional benefit the findings should be considered very cautiously. Only one of the studies was considered to be at low risk of bias, the sample sizes are relatively small (30 -66 patients) and only 7 RCTs contributed to the network meta-analysis. The reviewers also indicated that there was a high degree of heterogeneity and publication bias.


Primary Paper

Cao R, Li Q, Wu Q, Yao M, Chen Y, Zhou H. Effect of non-surgical periodontal therapy on glycaemic control of type 2 diabetes mellitus: a systematic review and Bayesian network meta-analysis. BMC Oral Health. 2019 Aug 6;19(1):176. doi:10.1186/s12903-019-0829-y. PubMed PMID: 31387569.

Other references

Dental Elf – 11th Nov 2015

Low quality evidence that periodontal treatment improves glycaemic control in diabetics


Dental Elf – Diabetes and Periodontal disease blogs


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