Occlusal reduction and post-endodontic pain


The incidence of pain following endodontic treatment is a concern to both patients and clinicians and is reported to occur in between 3-58% of cases. Hyper-occlusion/occlusal trauma is a potential cause of pain so studies have assessed occlusal reduction to remoe all occlusal contacts or occlusal adjustment (maintenance of normal occlusal contacts) to reduce post-endodontic pain.

The aim of this review was to analyse the influence of occlusal reduction on postoperative pain levels after endodontic treatment.


The review protocol was registered on PROSPERO and searches conducted in the LILACS (Latin American and Caribbean Health Sciences Literature database), Cochrane Library, PubMed (Medline), Web of Science, Scopus, Scielo, and ScienceDirect databases. Randomised controlled trials comparing occlusal reduction after endodontic treatment with a control were considered. Two reviewers independently searched and selected studies, extracted data and assessed risk of bias using the Cochrane risk of bias tool.  The main outcome was the presence or absence of pain summarised as relative risk (RR) and 95% confidence intervals (CI). The certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.


  • 12 studies involving 1461 patients and endodontic procedures were included.
  • All the studies included molar and premolar teeth.
  • Visual analogue scale (VAS) was the most commonly used method of pain assessment, verbal rating scale (VRS) numerical rating scale (NRS, and questionnaires were also used.
  • 5 studies were considered to be at low risk of bias and 7 at unclear risk.
  • 9 studies contributed to the meta-analyses, involving 8 studies for post-instrumentation pain and 3 for post obturation pain.
  • No difference was seen in post-instrumentation pain levels after occlusal reduction after: –
    • 6 hours:  RR = 0.96 (95%CI; 0.77 to 1.19)
    • 12 hours: RR = 0.86 (95%CI; 0.72 to 1.02)
    • 24 hours: RR = 0.91 (95%CI; 0.73 to 1.13)
    • 48 hours: RR = 0.94 (95%CI; 0.74 to 1.18)
  • Likewise, no difference was found in post root canal obturation pain following occlusal reduction
    • 6 hours: RR = 0.89 (95%CI; 0.72 to 1.11)
    • 12 hours: RR = 0.80 (95%CI; 0.51 to 1.25)
  • The GRADE certainty of the evidence was assessed a moderate.


The authors concluded: –

… occlusal reduction does not interfere with pain after endodontic instrumentation (at 6, 12, 24, or 48 h) and the obturation (at 6 and 12 h). The certainty of evidence within the studies included in this meta-analysis was considered moderate.


We last looked at this topic in August 2020 in a review by Nguyen et al (Dental Elf – 28th Aug 2020). The Nguyen review included 7 RCTs, while this new review includes 12 RCTs including all 7 studies from the Nguyen review.   This new review has searched a wide range of databases excluding one potentially relevant study because of language. Unlike the Nguyen review which focused on pain at 6 days this review reports on the initial 48-hour period. The findings of this review suggests that occlusal reduction provided no benefit in the first 48 hours while the findings from the Nguyen review suggest that at 6 days there is a benefit.  The findings of both reviews need to be considered carefully as the included studies are small and display significant levels of methodological heterogeneity with the use of variable clinical procedures, follow up periods and pain scales. Agreement on common outcome sets for future well conducted and reported RCTs of appropriate size would be helpful to provide further clarity in this clinical area.


Primary Paper

Chagas Carvalho Alves N, Raiane Mamede Veloso S, de Andrade Silva S, de Almeida AC, Tavares Velozo Telles C, Romeiro K, de Melo Monteiro GQ, de Albuquerque DS. Influence of occlusal reduction on pain after endodontic treatment: a systematic review and meta-analysis. Sci Rep. 2021 Jul 7;11(1):14019. doi: 10.1038/s41598-021-93119-6. PMID: 34234168; PMCID: PMC8263790.

Review protocol on PROSPERO

Other references

Dental Elf – 28th Aug 2020

Occlusal reduction: Does it reduce post endodontic pain?

Dental Elf – 31st Jan 2020

Post-endodontic pain: Is it reduced by occlusal reduction?



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