Outcome of secondary root canal treatment: a systematic review of the literature

By Ng YL, Mann V, Gulabivala K

Date: 10/2009
Journal: JOE

Purpose: To investigate the effects of study characteristics on the reported success rates of secondary root canal treatment; and (ii) to investigate the effects of clinical factors on the success of 2RCT.

N= 17 studies. inclusion criteria

1. Clinical study on secondary root canal treatment;

2. Stratified analyses available if primary root canal treatment cases had been included;

3. Sample size given and larger than 10;

4. At least a 6-month post-operative review.


•MEDLINE and Cochrane database 1966–2006 were searched electronically, hand searching involved 4 journals (Dental Traumatology, International Endodontic Journal, Journal of Endodontics, Oral Surgery Oral Medicine Oral Pathology Endodontics Radiology) and bibliographies of all relevant papers and review articles.

•Two reviewers assessed and selected the studies based on specified inclusion criteria.

•The pooled weighted success rates by each study characteristic (decade of publication, study-specific criteria for success, unit of outcome measure (tooth, root), duration after treatment when assessing success (‘at least 4 years’ or <4 years’), geographic location of the study and qualification of the operator) and potential prognostic factor were estimated using the random effect model.

Most highlighted Results: 

•The pooled weighted success rate of 2RCT judged by complete healing was 76.7% and by incomplete healing, 77.2%.

•The success rates by ‘decade of publication’ and ‘geographic location of study’ were not significantly different.

•the most frequently and thoroughly investigated factors were ‘periapical status, ‘size of lesion’ , and ‘apical extent of obturation’ which were found to be significant prognostic factors. Also, the quality of the coronal restoration was a significant prognostic factor.