A prospective cohort study evaluating the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions

Abstract

Aim To evaluate the impact of various predictors on the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions after a minimum of 2 years. Methodology One hundred and twenty previously root canal treated symptomatic mandibular first molars with periapical lesions which were diagnosed as symptomatic apical periodontitis or acute apical abscess with localized intraoral swelling were included. Root canal retreatment was performed by an experienced endodontist using a standardized treatment protocol. The teeth were followed up clinically and radiographically and the radiographic outcome was assessed using a modified periapical index scale (PAI). The cumulative success proportion and the influence of predictors on the outcome of the root canal retreatment were analysed using Kaplan–Meier analyses and log‐rank tests, and the hazard ratios for the predictors were also investigated using Univariate Cox Proportional Hazard regression analysis at a significance level of 5%. Results Of the 120 teeth, 103 teeth were re‐examined with an 85% recall rate. The cumulative success rate was 88% in which 64% were healed and 24% were healing, and failure rate was recorded as 12%. None of the preoperative predictors, including age, gender, soft tissue tenderness, intraoral swelling, size of the lesion, PAI score, apical level and density of root canal filling before root canal retreatment, nor intraoperative predictors, such as active exudate drainage, density of root canal filling after root canal retreatment and restoration type had an influence on the outcome of root canal retreatment (p > .05). The only factor that significantly reduced the success rate of root canal retreatment was the apical level of the root canal filling; when it was more than 2 mm short of the radiographic apex in teeth where apical patency was not established, the success was significantly lower (p = .023). Conclusions Root canal retreatment in symptomatic mandibular first molars with periapical lesions resulted in a success rate of 88%. None of the predictors had a significant influence on the outcome, except for the apical level of the root canal filling after root canal retreatment with short root fillings being associated with significantly more post‐treatment endodontic disease.

The outcome of single-visit nonsurgical retreatment and patients’ perception of retreatment: a retrospective cohort study with 1-year follow-up

“…In the present study, tooth type had no influence on healing rate and these results are similar to some previous studies, on the other hand opposing results identifying tooth type as an outcome predictor have been reported and lower healing rates in molars was attributed to the complexity of molar root canal anatomy (17,21,22). In accordance with previous studies, gender and preoperative PAI scores did not influence the outcome of nonsurgical retreatment in our study (13,21).…”

“…In the present study, previously formed ledges that could not be bypassed, previously separated instruments that could not be removed, and missed root canals due to the lack of use of a dental operating microscope might directly or indirectly lead to the failed cases. Unlike some of the previous studies, teeth with separated instruments were included in our study, since nonsurgical retreatment is a rational option for certain cases with separated instruments (13,15). We believe studies including cases with previous procedural complications might reflect more realistic outcomes of nonsurgical retreatment cases.…”

“…While Van Nieuwenhuysen et al (12) reported improved outcomes with multiple visits, the study of Farzaneh et al (10) showed no significant difference. Although it was shown that active exudate drainage had no influence on the outcome of retreatment, teeth with active exudate drainage were excluded due to the potential postoperative complications after singlevisit retreatment (13).…”

Macrophages in periapical lesions: Potential roles and future directions

“…The treatment success rate for PLs, including those operated on by endodontic experts or specialists, is only just over 50% after 2 years’ follow-up ( 4 , 5 ). Thus, despite “optimal treatment”, hundreds of thousands of teeth continue to be affected by PLs, causing symptomatic infection ( 5 , 6 ). Therefore, it is essential to elucidate the mechanism of development of PLs, and to identify more effective and longer-lasting treatments ( 2 ).…”

Outcome of single‐ versus two‐visit root canal retreatment in teeth with periapical lesions: A randomized clinical trial

“…However, there is no consensus about this issue in the root canal retreatment cases yet, and a multiple‐visits approach still is the most preferred endodontic management especially in teeth with periapical lesions. Although the outcome of multiple‐visit root canal retreatment have been evaluated in many retrospective (Calıskan, 2005; Dammaschke et al, 2003; Olcay et al, 2019) and prospective studies (Al‐Nuaimi et al, 2017; Davies et al, 2016; Farzaneh et al, 2004; Gorni & Gagliani, 2004; He et al, 2017; Metska et al, 2013; Ng et al, 2011; Riis et al, 2018; Serefoglu et al, 2021; Sundqvist et al, 1998; Zandi et al, 2019; Zhang et al, 2021), the number of studies evaluating root canal retreatment in a one‐visit approach is very limited, and these studies are retrospective in nature (Ashraf et al, 2007; Eyuboglu et al, 2017; Ng et al, 2011). To the best of author's knowledge, there is no prospective study comparing the success rate of single‐ and two‐visit root canal retreatments to determine the effect of the number of visits on the outcome.…”