The aim of this retrospective cohort study conducted by Sim et al from the National Dental Centre, Singapore, was to examine the 5-year survival rate of teeth with cracks and to determine which factors influenced the outcome. A total of 200 patients who had root canal-treated posterior cracked teeth were recalled for a 5-year review. The cases were managed following the treatment protocol for cracked teeth. Patient records were coded to maintain anonymity. Eighty-four patients met the inclusion criteria and were included in this study.

The data for analysis were taken from the patients’ clinical records. Pretreatment data included race and sex; type of tooth; location of the tooth (maxillary or mandibular) and whether it was the terminal tooth; number of cracks (single or multiple); extent (coronal or radicular); location of crack lines (mesial, distal, buccal or palatal/lingual); presence of periodontal pocketing; soft tissue status such as presence of swelling and sinus tract; pulpal and periapical status; type of restoration before root canal treatment and pretreatment radiograph.

  • Data obtained from the patients’ followup review records included
  • tenderness to percussion and palpation
  • presence of pocketing (sites and depth)
  • soft tissue status, such as presence of swelling and sinus tract
  • type of restoration
  • periapical radiographs

When a tooth was missing at the review session, the reason for the extraction was recorded when known. Two independent clinicians were

calibrated and subsequently blinded to the evaluation of the coded pretreatment and recall radiographs. A consensus for any discrepancy that transpired was obtained by the evaluators. Statistical analyses were performed using SPSS 21.0. The outcome measure was the presence of the tooth at the time of the review.

At 5 years, 77 teeth survived (92%) and 7 teeth (8%) were extracted. Patient demographics, tooth type and location, existing restoration, number and location of cracks, presence of pretreatment signs and symptoms, and initial pulpal and periapical diagnosis did not affect the survival of the teeth. Multivariable analysis
found that extension of cracks onto the pulpal floor increased the odds of tooth loss by 11-fold (odds ratio, 11; p = .033) with other factors remaining constant. The 5-year survival estimate, in the absence and presence of crack extension onto the pulpal floor, was 99% and 88%, respectively.


The authors’ data showed that an endodontically treated cracked tooth could remain functional and may survive for 25 years. Coronal cracks are successfully treated in most cases, but radicular cracks or cracks extending onto the pulpal floor and beyond increased the odds of the tooth being extracted. However, even 81.8% of these teeth survived the 5-year follow-up period.

Sim 1GB, Lim TrS, Krishnaswamy G, Chen N —N . Decision making for retention of endodontically treated posterior cracked teeth: a 5ryear follow’up study. J Endod 2016;doi:10.1016/j.joen.2015.11.011.