Meta-analysis Assessing Persistent Pain Following Root Canal Therapies

The incidence of persistent pain following root canal therapies is not well known, even thought 16.4 million are performed yearly in the USA.

Objectives: Determine the incidence of ‘all cause' pain ³6 months following endodontic procedures, via meta-analysis of published literature, and describe the quality of the reported research.

Methods: MEDLINE database search, from 1950 to November 2007, using PubMed keywords associated with pain and endodontic procedures. Citations were screened by 2 reviewers following training with acceptable inter-rater reliability. Criteria for article selection were: 1) endodontic procedures including pulpectomy, pulpotomy and apical surgery but not root desensitization, pulp capping or concomitant extraction; 2) procedure performed on human secondary teeth, with a tooth as unit of observation; 3) ‘all-cause' pain defined as any pain report including those provoked by percussion, palpation or biting; and 4) follow up duration of ³6 months. Quality of reported research was determined by means of applying a modified version of the STROBE criteria. Consensus between reviewers was required for all end-points. Random effects meta-analysis was used to derive a pooled estimate of the incidence.

Results: The search identified 463 articles and abstract screening eliminated 285 articles. Inter-rater reliability was good (k=0.79). Full article review of the remaining 187 articles resulted in 18 meeting the selection criteria; 5 with ‘fair' quality and 13 with ‘marginal' quality. Notable publications did not meet the criteria, while 2 foreign language articles fitted and were included after translation. The overall incidence of ‘all-cause' persistent pain was determined to be 6-9% (95%CI=4-8% and 95% CI=6-12%). Study quality did not influence estimates in a meta-regression (P=0.77 or P=0.78).

Conclusions: The ‘all-cause' incidence of pain following root canal therapies was 6-9% based on available literature that was not of high quality. Further research of better quality is needed.

Supported by NCRR K12-RR023247 (DR Nixdorf)