Chlorhexidine chip as adjunct to scaling and root planing in patients with chronic periodontitis


Chronic periodontal disease is common and left untreated is an important cause of tooth loss in adults. The main basis of treatment is scaling and root planning alone or in combination with adjuncts. These adjuncts may include locally antimicrobials (chlorhexidine chips, doxycycline hyclate gel and minocycline microspheres) or systemic antimicrobials at standard and sub-anti-microbial dosages and other adjuncts.

The aim of this review was to assess the efficacy of sub-gingival chlorhexidine chips when used as adjunct to scaling and root planing for non-surgical treatment of periodontal pockets in patients with chronic periodontitis.


Searches were conducted in the Medline/PubMed, Cochrane Central Register of Controlled Trials (CENTRAL)and Scopus databases. There were supplemented by manual searches of the journals; Clinical Oral Investigations, European Journal of Oral Sciences, Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Dentistry, Journal of Periodontal Research, Journal of Periodontal and Implant Science, and Journal of Periodontology.

Randomised controlled trials (RCTs) employing chlorhexidine chips as an adjunct to scaling and root planing (SRP) in patients with chronic periodontitis with a follow up period of at least one month and published between 2006-2020 were considered. Outcomes included probing pocket depth (PPD), clinical attachment level (CAL), gingival inflammation and microbiological findings. Data was extracted by two reviewers independently with continuous data being pooled using the mean differences (MD) with 95% confidence intervals (CI).  Risk of bias assessment was also conducted by two reviewers independently used the Cochrane domains-based tool.


  • 15 RCTs (9 split mouth, 6 parallel) involving a total of 620 patients and 998 treatment sites were included.
  • The chlorhexidine (CHX) chips had 2.5mg CHX embedded in a collagen matrix.
  • 4 studies were considered to have a low risk of bias, 8 a moderate risk and 3 a high risk.
  • 14 studies contributed to the meta-analyses.
  • Meta-analyses showed that sites treated with SRP and CHX chip had better PPD and CAL outcomes than the sites treated with SRP alone at 1,3 and 6 months follow up.
Follow up period No. of studies PPD Reduction

MD (95%CI)

CAL gains

MD (95%CI)   

1 month 10 0.63 (0.44 – 0.82) 0.54 (0.26 – 0.81)
3 months 13 0.69 (0.43 – 0.95) 0.64 (0.36 – 0.92)
6 months 4 0.75 (0.72 – 0.77) 0.68 (0.65 – 0.70)
  • Meta-analyses also showed better improvements for gingival inflammation for sites treated with SRP and CHX that with SRP alone at 1 and 3 months:-
    • 1 month; MD = 0.29 (95%CI; 0.06–0.52), [5 studies].
    • 3 months; MD = 0.32 (95%CI; 0.15–0.48), [6 studies].


The authors concluded: –

…..our results indicate that clinical outcomes may be significantly improved in patients undergoing non-surgical therapy for periodontal pockets with the adjunctive use of CHX chip after SRP as compared to SRP alone. The overall quality of evidence is moderate. Further trials focusing on microbiological outcomes are needed to assess the efficacy of CHX in reducing the load of periodontal pathogens.


The American Dental Association (ADA) conducted a review of SRP with and without adjuncts (Smiley et al, 2015) for their 2015 clinical practice guideline on nonsurgical treatment of chronic periodontitis. There have also been a number of other relevant reviews of this area (Dental Elf – 8th Jul 2020), and in addition to the review considered here another on the same topic was recently published (Wang CY et al, 2020).

The authors of this review have searched a wide range of databases although they have used a restricted time frame (2006-2020) which could have excluded relevant studies. While the text of the paper suggests that 4 of the included studies were at low risk of bias the risk of bias figure indicates that only 3 studies were a low risk in all six domains. Seven of the RCTs included in this review were published after the ADA review, however of the other 8 included only two were included in the ADA review. A majority of the included studies were split-mouth studies and while the CHX chips provide local delivery it is worth considering if there is any potential for cross-over effects. Although interestingly the meta-analyses shown comparing split-mouth and parallel studies suggest a smaller effect in parallel studies.

The ADA review (Smiley et al, 2015) provides a suggestion for interpreting CAL results in a clinical context

CAL Difference Range (mm) Judged clinical relevance
0 – 0.2 No benefit
>0.2 – 0.4 Small benefit
>0.4 – 0.6 Moderate benefit
>0.6 Substantial benefit

While this would suggest that there is a substantial clinical benefit for CAL at 3 and 6 months from using CHX chips. It should be noted that the confidence intervals are quite wide and that the analyses was based on tooth site rather than patients or whole mouth measurements.


Primary Paper

Ma L, Diao X. Effect of chlorhexidine chip as an adjunct in non-surgical management of periodontal pockets: a meta-analysis. BMC Oral Health. 2020 Sep 21;20(1):262. doi: 10.1186/s12903-020-01247-8. PMID: 32957945; PMCID: PMC7507294.

Other references

Wang CY, Yang YH, Li H, Lin PY, Su YT, Kuo MY, Tu YK. Adjunctive local treatments for patients with residual pockets during supportive periodontal care: A systematic review and network meta-analysis. J Clin Periodontol. 2020 Oct 3. doi: 10.1111/jcpe.13379. Epub ahead of print. PMID: 33010026.

Smiley CJ, Tracy SL, Abt E, Michalowicz BS, John MT, Gunsolley J, Cobb CM, Rossmann J, Harrel SK, Forrest JL, Hujoel PP, Noraian KW, Greenwell H, Frantsve-Hawley J, Estrich C, Hanson N. Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts. J Am Dent Assoc. 2015 Jul;146(7):508-24.e5. doi: 10.1016/j.adaj.2015.01.028. PMID: 26113099.

Dental Elf – 8th Jul 2020

Antiseptics as adjuncts to nonsurgical periodontal treatment

Dental Elf – 7th Feb 2020

Chlorhexidine gel as an adjunct to non-surgical periodontal treatment

Dental Elf – 9th Aug 2017

Scaling and root planing adjuncts for chronic periodontitis




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