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Eight-year retrospective study investigating tooth survival after primary non-surgical root canal treatment in a UK military cohort
  1. Richard Blake Smith1,
  2. G E Bryce2,
  3. Y Ng3,4,
  4. K Gulabivala4 and
  5. M A Dermont5
  1. 1Dental Centre Colchester, Defence Primary Healthcare, Colchester, UK
  2. 2DCRD, Aldershot Garrison, Aldershot, UK
  3. 3Endodontology, University College London, London, UK
  4. 4Restorative Dentistry and Endodontology, UCL Eastman Dental Institute, London, UK
  5. 5Defence Public Health Unit, Defence Medical Services, Lichfield, UK
  1. Correspondence to LtCol Richard Blake Smith, Dental Centre Colchester, Defence Primary Healthcare, Colchester C02 7UT, UK; Richard.smith740{at}


Introduction Root canal treatment (RCT) plays an important role in preserving the dentition by deferring other invasive treatments. Data on tooth survival and predictive factors for tooth loss after RCT in the military cohort are lacking. This investigation aimed to determine the proportion of teeth surviving in an 8-year period after RCT and identify potential predictive factors for tooth loss in a UK military cohort.

Methodology A retrospective review of an integrated electronic health record for military patients who had received RCT was performed in a random sample of 205 patients (n=219 root-filled teeth) who had received RCT between 1 January 2011 and 1 January 2012. Tooth survival was defined as tooth presence, regardless of signs or symptoms, and measured from the point of root filling until either the end of the designated study period or time of extraction. Survival was evaluated using Kaplan-Meier estimates and association with tooth loss using the χ2 test. Potentially significant predictive factors were investigated using univariate Cox regression.

Results Tooth survival following RCT was 98% after 24 months; 88% after 48 months; 83% after 72 months; and 78% after 96 months. Four predictive factors were found to affect tooth loss as follows: preoperative pain (HR=3.2; p<0.001), teeth with less than two proximal contacts (HR=3.0; p=0.01), teeth with cores involving more than two surfaces (HR=2.0; p=0.03) and postoperative unscheduled dental attendances (UDA) (HR=2.7; p=0.01).

Conclusions Within the limitations of this study, the presence of preoperative pain; teeth with less than two proximal contacts or with cores involving more than two tooth surfaces; and occurrence of postoperative UDA were found to significantly increase the hazard of tooth loss.

  • clinical audit
  • oral & maxillofacial surgery
  • audit

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  • Contributors Basic study idea by RBS and GEB. Approval as service evaluation by RBS and MAD. MOD data protection impact assessments and data access approvals by RBS and MAD. Protocol editing and review by KG and YN. Pilot data collection by RBS and GEB. Manuscript editing and review by RBS, GEB, KG and YN. Guarantor: RBS.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.