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Only a Small Percentage of Patients Experience Persistent Pain for More than 6 Months After Root Canal Therapy
REVIEW ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Frequency of persistent tooth pain after root canal therapy: a systematic review and metaanalysis. Nixdorf DR, Moana-Filho EJ, Law AS, McGuire LA, Hodges JS, John MT. J Endod 2010;36(2):224-30.
REVIEWER Analia Veitz Keenan, DDS
PURPOSE/QUESTION
Only a Small Percentage of Patients Experience Persistent Pain for More than 6 Months After Root Canal Therapy SUMMARY Selection Criteria The systematic review was limited to studies of endodontic procedures, which included cohort studies and clinical trials that had enough data to calculate the frequency of occurrence of postoperative pain. Four electronic databases (Medline via PubMed, the Cochrane Library, Trip database, and Google Scholar) were searched for articles written in any language from 1949 to 2009 with a specific search strategy. Hand searching was performed along with the search of references in relevant articles, literature reviews, and textbook chapters. Articles were screened by more than one reviewer.
The aim of the study was to assess the frequency of pain at 6 months or more in association with endodontically treated permanent teeth.
Key Study Factor
SOURCE OF FUNDING
Main Outcome Measure
Information not available
The outcome was persistent pain, reported by the patient or the practitioner, in endodontically treated permanent teeth.
TYPE OF STUDY/DESIGN
Main Results
Systematic review with metaanalysis
From the 770 articles selected, 26 articles met the inclusion criteria and were included in the meta-analysis. The articles represent 5777 teeth enrolled, and 2996 teeth were followed up after at least 6 months. A high heterogeneity was present among the studies, and variation in the quality of reporting was observed. A quality assessment of each study was performed using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) rating.1 The results show that the frequency of persistent pain, from all causes over the 26 studies, was 5.3% (95% confidence interval [CI] 3.5%-7.2%). A subgroup analysis was performed, and higher-quality studies had a higher frequency of persistent pain (8.3%), whereas lower-quality studies had a lower frequency of persistent pain (1.4%). Retrospective studies had the lowest estimated pain frequency (0.9%), and prospective studies had a higher estimate (7.6%).
LEVEL OF EVIDENCE Level 1: Good-quality patientoriented evidence
STRENGHT OF THE RECOMMENDATION GRADE Grade A: Consistent, good-quality patient-oriented evidence
The reporting unit was the tooth. A secondary objective of the review was to analyze the influence of treatment approach, study design, follow-up rate and duration, initial treatment versus retreatment, and quality of reporting.
Conclusion
J Evid Base Dent Pract 2010;10:235-236 1532-3382/$36.00 Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2010.09.001
The estimate of the frequency of all-cause tooth pain at 6 months or longer after root canal treatment of permanent teeth is approximately 5%. In the context of this review, the estimated persistent pain associated with endodontic treatment is low, but future studies with better methodological quality could be beneficial for refining the magnitude of persistent pain frequency. The knowledge could influence the decision process for patients and providers.
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
COMMENTARY AND ANALYSIS Weaknesses and Strengths This was a well-done systematic review with a comprehensive search. The inclusion of an extensive hand search and a search of all non-English language studies demonstrated that it is important to consider articles published in other languages.The total number of studies selected for this review (n = 26) included 24 published in English, 1 in French, and 1 in Chinese. A sensitivity analysis and a quality assessment of the individual studies were performed to reduce the possibility of bias. These assessments were performed using an international tool to improve reporting quality of epidemiological studies (STROBE).1 There are a total of 22 items comprising the STROBE tool assessment and the authors assigned equal weight to each item to produce a quality score range of 0 to 22. Among the 26 studies analyzed, only 6 were ranked above 19, and the median reporting quality score was 8.5. A reasonable number of studies were selected, but they were very different in study design, outcome measured, endodontic techniques performed, and follow-up time. The average loss to follow-up of patients/teeth was high at 48%. Retrospective studies had a higher risk of bias (recall bias) than prospective studies, where the outcome of interest could be more accurately analyzed and properly weighted in the review. The authors did report a slightly higher estimate of chronic pain of 6 months or longer (>7%) when their analyses were restricted to studies with higher STROBE scores and when studies used a prospective design as compared with a retrospective study design.
Implications for Dental Practice Chronic pain is an outcome we want to avoid as practitioners. Many patients want to avoid or delay dental treatment if it is known that pain will be associated with
236
the dental procedure. Also, pain is an outcome that can differ from patient to patient. Root canal treatments are always associated with acute and chronic pain, and are associated with anxiety and fear. Because root canal therapy is a very complex procedure, there are many factors that can be involved in the success and failure of the endodontically treated tooth and pain associated with the treatment. Those factors are status of the tooth before the treatment, techniques used, materials used to clean the canals, instruments used to shape the canals, cements, sealers, guta percha, microleakage, and materials and techniques to restore previously endodontically treated teeth. The present review showed that a small percentage of people will experience chronic pain for 6 months or more following root canal therapy. Although the number of people who will experience persistent endodontic pain appears to be minor statistically speaking, it is an important issue for each patient who experiences the pain. This systematic review did not address pain management issues; however, appropriate management of the pain for each individual is important.
REFERENCE 1. Vandenbroucke JP, von Elm E, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, et al. STROBE initiative. Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration. Ann Intern Med 2007;147:W163-94.
REVIEWER Analia Veitz Keenan, DDS Clinical Assistant Professor Private Practice, PI PEARL NETWORK Brooklyn, NY 11229 718-934-1020 [email protected]
December 2010
REVIEWER Analia Veitz Keenan, DDS
PURPOSE/QUESTION
Only a Small Percentage of Patients Experience Persistent Pain for More than 6 Months After Root Canal Therapy SUMMARY Selection Criteria The systematic review was limited to studies of endodontic procedures, which included cohort studies and clinical trials that had enough data to calculate the frequency of occurrence of postoperative pain. Four electronic databases (Medline via PubMed, the Cochrane Library, Trip database, and Google Scholar) were searched for articles written in any language from 1949 to 2009 with a specific search strategy. Hand searching was performed along with the search of references in relevant articles, literature reviews, and textbook chapters. Articles were screened by more than one reviewer.
The aim of the study was to assess the frequency of pain at 6 months or more in association with endodontically treated permanent teeth.
Key Study Factor
SOURCE OF FUNDING
Main Outcome Measure
Information not available
The outcome was persistent pain, reported by the patient or the practitioner, in endodontically treated permanent teeth.
TYPE OF STUDY/DESIGN
Main Results
Systematic review with metaanalysis
From the 770 articles selected, 26 articles met the inclusion criteria and were included in the meta-analysis. The articles represent 5777 teeth enrolled, and 2996 teeth were followed up after at least 6 months. A high heterogeneity was present among the studies, and variation in the quality of reporting was observed. A quality assessment of each study was performed using the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) rating.1 The results show that the frequency of persistent pain, from all causes over the 26 studies, was 5.3% (95% confidence interval [CI] 3.5%-7.2%). A subgroup analysis was performed, and higher-quality studies had a higher frequency of persistent pain (8.3%), whereas lower-quality studies had a lower frequency of persistent pain (1.4%). Retrospective studies had the lowest estimated pain frequency (0.9%), and prospective studies had a higher estimate (7.6%).
LEVEL OF EVIDENCE Level 1: Good-quality patientoriented evidence
STRENGHT OF THE RECOMMENDATION GRADE Grade A: Consistent, good-quality patient-oriented evidence
The reporting unit was the tooth. A secondary objective of the review was to analyze the influence of treatment approach, study design, follow-up rate and duration, initial treatment versus retreatment, and quality of reporting.
Conclusion
J Evid Base Dent Pract 2010;10:235-236 1532-3382/$36.00 Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2010.09.001
The estimate of the frequency of all-cause tooth pain at 6 months or longer after root canal treatment of permanent teeth is approximately 5%. In the context of this review, the estimated persistent pain associated with endodontic treatment is low, but future studies with better methodological quality could be beneficial for refining the magnitude of persistent pain frequency. The knowledge could influence the decision process for patients and providers.
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
COMMENTARY AND ANALYSIS Weaknesses and Strengths This was a well-done systematic review with a comprehensive search. The inclusion of an extensive hand search and a search of all non-English language studies demonstrated that it is important to consider articles published in other languages.The total number of studies selected for this review (n = 26) included 24 published in English, 1 in French, and 1 in Chinese. A sensitivity analysis and a quality assessment of the individual studies were performed to reduce the possibility of bias. These assessments were performed using an international tool to improve reporting quality of epidemiological studies (STROBE).1 There are a total of 22 items comprising the STROBE tool assessment and the authors assigned equal weight to each item to produce a quality score range of 0 to 22. Among the 26 studies analyzed, only 6 were ranked above 19, and the median reporting quality score was 8.5. A reasonable number of studies were selected, but they were very different in study design, outcome measured, endodontic techniques performed, and follow-up time. The average loss to follow-up of patients/teeth was high at 48%. Retrospective studies had a higher risk of bias (recall bias) than prospective studies, where the outcome of interest could be more accurately analyzed and properly weighted in the review. The authors did report a slightly higher estimate of chronic pain of 6 months or longer (>7%) when their analyses were restricted to studies with higher STROBE scores and when studies used a prospective design as compared with a retrospective study design.
Implications for Dental Practice Chronic pain is an outcome we want to avoid as practitioners. Many patients want to avoid or delay dental treatment if it is known that pain will be associated with
236
the dental procedure. Also, pain is an outcome that can differ from patient to patient. Root canal treatments are always associated with acute and chronic pain, and are associated with anxiety and fear. Because root canal therapy is a very complex procedure, there are many factors that can be involved in the success and failure of the endodontically treated tooth and pain associated with the treatment. Those factors are status of the tooth before the treatment, techniques used, materials used to clean the canals, instruments used to shape the canals, cements, sealers, guta percha, microleakage, and materials and techniques to restore previously endodontically treated teeth. The present review showed that a small percentage of people will experience chronic pain for 6 months or more following root canal therapy. Although the number of people who will experience persistent endodontic pain appears to be minor statistically speaking, it is an important issue for each patient who experiences the pain. This systematic review did not address pain management issues; however, appropriate management of the pain for each individual is important.
REFERENCE 1. Vandenbroucke JP, von Elm E, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, et al. STROBE initiative. Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration. Ann Intern Med 2007;147:W163-94.
REVIEWER Analia Veitz Keenan, DDS Clinical Assistant Professor Private Practice, PI PEARL NETWORK Brooklyn, NY 11229 718-934-1020 [email protected]
December 2010