Outcome of selective root canal retreatment-A retrospective study

Abstract

Aim: Selective root canal retreatment is when the treatment is limited to root(s) with radiographic evidence of periapical pathosis. The goals of this retrospective study were as follows: (i) evaluate the clinical and radiographic (periapical radiographs [PR] or cone-beam computerized tomographs [CBCT]) outcome of selective root canal retreatment after ≥12 months follow-up; (ii) evaluate the periapical status of the unretreated roots; and (iii) assess tooth survival.

Methodology: A retrospective study (January 2018 to April 2021) was conducted to identify permanent multirooted teeth that underwent selective root canal retreatment. Clinical records, PR and CBCT were examined to ascertain variables of interest. Outcomes (per root and per tooth) were classified into 'favourable' or 'unfavourable' using well-established clinical and radiographic healing criteria. Treatment outcomes for the whole tooth and per root were compared as well as bivariate associations between the treatment outcome of the retreated roots and the treatment-related parameters (quality of root filling, sealer extrusion, iatrogenic mishaps and type of restoration) were analysed using Fisher's exact test (α = .05). Survival was recorded in months.

Results: A total of 75 teeth (195 roots) in 75 subjects were available for outcome analysis. The favourable outcome per tooth was 86.7%. At follow-up, 92.6% of the retreated roots had a favourable outcome. From the unretreated roots, 3.5% showed radiographic signs of an emerging periapical lesion. No statistical difference was shown between the outcomes per root and per tooth between both groups. None of the treatment-related parameters had a direct influence on the outcome of the retreated roots. The survival rate at 12-48 months after retreatment was 91.5%.

Conclusions: Selective root canal retreatment is associated with a favourable outcome in a majority of cases. Unretreated roots rarely developed radiographic signs of a new periapical lesion at follow-up. Future high-quality clinical trials with larger sample sizes and longer follow-up periods are required to confirm these findings.

Keywords: cone-beam computed tomography; endodontic outcome; minimally invasive; nonsurgical retreatment; periapical radiography; selective root canal retreatment.

FIGURE 1

Flow chart describing the process of inclusion and exclusion of cases for the purpose of participation eligibility. (S, subjects; T, teeth; R, roots).

FIGURE 2

Pre‐treatment (a), post‐treatment (b) and follow‐up (c) periapical radiographs used for outcome assessment. 2A reveals an example of complete resolution of periapical radiolucency of tooth 26 after selective retreatment of the mesiobuccal and distobuccal roots at 15 months follow‐up; 2B shows an example of a case with a reduction in size of the periapical radiolucency after selective retreatment of the mesiolingual canal on the mesial root of tooth 36, at 12 months follow‐up; 2C shows an example of an unfavourable case – at 24 months follow‐up, a pre‐existing periapical radiolucency remained unchanged after selective retreatment of the mesiobuccal root of tooth 26.