Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment

Exploring Technological Progress in Three-Dimensional Imaging for Root Canal Treatments: A Systematic Review

INTRODUCTION AND AIMS

Root canal therapy is a crucial aspect of endodontic treatment aimed at preserving natural dentition. Over the years, advancements in three-dimensional (3D) technology have revolutionized diagnosis and treatment planning. Different 3D technologies are used in dental care, such as cone-beam computed tomography (CBCT), which ensures 3D slice visualization, root canal microanatomy, and dynamic navigation throughout the pulp cavity. By exploring the latest technological progress in this field, we seek to understand how these innovations are enhancing precision, efficiency, and patient outcomes, shedding light on the benefits and potential impact of 3D imaging in improving root canal procedures.

METHODS

Literature was searched from different databases, including PubMed, ScienceDirect, The Cochrane Library, Scopus, and Google Scholar. Inclusion criteria involved studies on 3D technology in root canal therapy with comparison groups, including RCTs and non-RCTs. Excluded studies lacked 3D imaging advancements, a control group, or were review articles or case studies. Quality assessment utilized QUIN for in vitro studies and ROBINS-I for non-RCTs to evaluate the studies' validity.

RESULTS

According to the PRISMA guidelines, among 5015 initial articles, 16 were included. CBCT was the most used 3D imaging technique for root imaging followed by micro-computed tomography (MCT) and limited CBCT (LCBCT) imaging methods. 2D radiographs and 2D histological methods and clearing techniques were the most common comparative modalities. Overall, 3D imaging streamlined dental treatment as clinicians could visualize much clearer and higher-quality images. Different resolutions and voxel sizes were applied to improve imaging quality.

CONCLUSION

Three-dimensional imaging, especially CBCT, improves root canal treatments by providing superior image quality. CBCT outperforms other techniques like MCT and LCBCT, enhancing clarity. Varying resolutions and voxel sizes optimize the effectiveness of 3D imaging in root canal therapy.

CLINICAL RELEVANCE

The advancements in 3D imaging technology, particularly CBCT, have significantly enhanced the diagnosis and treatment planning for root canal therapy. CBCT provides detailed insights into intricate root canal anatomy, improving diagnostic accuracy.

Diagnostic Accuracy of a Commercial AI-based Platform in Evaluating Endodontic Treatment Outcomes on Periapical Radiographs Using CBCT as the Reference Standard

INTRODUCTION

Artificial intelligence (AI) has shown promise in dental diagnostics; however, its accuracy in assessing endodontic treatment outcomes compared to experienced clinicians remains unclear. This study evaluated the performance of an AI-driven platform (Diagnocat) against experienced clinicians in assessing endodontic treatment outcomes on periapical radiographs, using cone-beam computed tomography as the reference standard.

METHODS

This retrospective diagnostic accuracy study analyzed 376 teeth (860 roots) from 4 prospective clinical trials. Treatment outcomes were assessed using periapical radiographs, independently evaluated by 2 calibrated endodontists and the AI-driven platform. Cone-beam computed tomography scans served as the reference standard. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve were calculated.

RESULTS

The AI-driven platform demonstrated higher sensitivity but lower specificity than clinicians at both tooth (sensitivity: 67.3% vs 49.3%, P < .001; specificity: 82.3% vs 92.5%, P < .001) and root levels (sensitivity: 54.3% vs 43.8%, P = .003; specificity: 86.7% vs 94.5%, P < .001). Overall accuracy was comparable at the tooth level (AI: 76.3%, clinicians: 75.3%, P = .716) but slightly lower for the AI-driven platform at the root level (78.5% vs 81.6%, P = .021). Receiver operating characteristic curve analysis showed comparable area under the curve values between the AI-driven platform and clinicians at both tooth (0.75 vs 0.71) and root levels (0.71 vs 0.69).

CONCLUSIONS

While the AI-driven platform demonstrated potential as an adjunctive tool for assessing endodontic treatment outcomes, particularly in detecting lesions that might be missed by human assessment, its lower specificity highlights the need for clinical oversight to prevent overdiagnosis.

CBCT-Assessed Outcomes and Prognostic Factors of Primary Endodontic Treatment and Retreatment: A Systematic Review and Meta-Analysis

INTRODUCTION

Periapical radiographs have limitations in assessing endodontic treatment outcomes, which can be addressed by cone-beam computed tomography (CBCT). This systematic review evaluates primary root canal treatment and retreatment outcomes using CBCT, focusing on periapical healing, success, and prognostic factors.

METHODS

A literature search (in PubMed, Embase, and Web of Science) was performed up to March 8, 2024, in collaboration with a medical information specialist. Three reviewers (J.F.B.M., A.C.G, P.D.N.) independently performed article selection and data extraction. Risk of bias was assessed, and evidence quality using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Meta-analysis and meta-regression established pooled periapical healing and outcome rates, 95% confidence intervals (CIs), and identify outcome predictors (P < .05).

RESULTS

Nineteen studies were included in the meta-analysis. The pooled periapical healing rate using "loose criteria" was 87% (95% CI: 81%-91%) for teeth and 84% (95% CI: 78%-88%) for roots; using "strict criteria" was 36% (95% CI: 22%-53%) for teeth, and 44% (95% CI: 16%-76%) for roots. The weighted pooled success rates for teeth were 85% (95% CI: 80%-89%) under "loose criteria" and 45% (95% CI: 31%-59%) under "strict" criteria. Meta-regression identified outcome predictors include number of visits, irrigant type, tooth type, operator experience, apical preparation size and taper, and obturation technique.

CONCLUSIONS

CBCT reveals lower success rates under strict criteria compared to loose criteria (36% vs 88%). While CBCT offers greater diagnostic accuracy, its routine use for outcome evaluation may not be necessary, as it yields results similar to periapical radiograph under loose criteria.

Five-Year Outcomes of Root Canal Treatment Comparing Sealer-Based Obturation With Calcium Silicate-Based Sealer to Continuous Wave of Condensation: A Randomized Controlled Trial

INTRODUCTION

While sealer-based obturation (SBO) with calcium silicate-based sealers has shown promise in short-term studies, including a previous randomized controlled trial comparing it to the continuous wave of condensation (CWC) technique, long-term evidence on its clinical performance remains limited. This study addresses this critical gap by following the same patient cohort for 5 years to evaluate the long-term clinical and radiographic outcomes of both techniques and investigate factors influencing long-term success.

METHODS

Patients were initially randomized at the time of obturation into 2 treatment groups, based on the obturation protocol: CWC with AH Plus sealer and SBO with Endoseal TCS (TriCalcium Silicate). Postobturation pain was assessed using a numerical rating scale. Root canal obturation quality was evaluated for sealer extrusion, filling voids, and root filling level. Five-year follow-up examinations assessed healing based on periapical index score reduction and symptom resolution. Statistical analysis included chi-square or Fisher's exact tests and multivariate logistic regression.

RESULTS

Of the initial 93 teeth, 60 (64.5% recall rate) were available for analysis after 5 years (mean follow-up: 62 months). Four teeth were extracted for nonendodontic reasons, leaving 56 teeth (CWC: 33; SBO: 23) for evaluation. Success rates showed no significant differences between groups under both loose (overall: 83.9%; CWC: 81.8%; SBO: 87.0%) and strict criteria (overall: 76.8%; CWC: 75.8%; SBO: 78.3%). No analyzed factors significantly correlated with long-term success.

CONCLUSION

The SBO technique with Endoseal TCS demonstrated comparable 5-year outcomes to the CWC technique, supporting its potential as a less technique-sensitive and clinically viable alternative for root canal obturation.

Current Trends in Endodontic Clinical Practice in Croatia: A Report From a Croatian National Survey

OBJECTIVE

To assess the state of endodontic practices and identify factors influencing the use of modern endodontic techniques among dental practitioners in Croatia.

MATERIALS AND METHODS

A questionnaire was distributed to all dental offices in Croatia, yielding 819 responses (27% response rate). Data were descriptively analyzed and statistically modeled.

RESULTS

Nearly 74% of endodontic treatments in Croatia are performed by general practitioners (17 teeth per month per practitioner), while endodontic specialists handle the highest number of treatments per specialist (67 teeth per month, representing 15% of total treatments). 56% of respondents use radiography before the procedure "always" or "almost always" with intra-oral periapical radiography being the most commonly used technique. Rubber dams are used "never" to "rarely" by 74% of respondents. Apex-locators are highly prevalent, used "almost always" to "always" by 83% of practitioners. Magnifiers are rarely used, with 63% of respondents reporting they "never" use them. Lasers are never used by 92% of respondents, whereas 59% frequently use engine-driven instrumentation. 76% of respondents "always" or "almost always" determine the working length of the root canal. Sodium hypochlorite is the most common irrigant (88%), and EDTA for smear layer removal is used by 36% of respondents. The cold lateral condensation is the most popular obturation technique (64%). CBCT is unused by 59% of responders, most probably because it is not accessible.

CONCLUSIONS

Croatian endodontic practices are comparable to those in countries with similar economic status, but there is substantial potential, particularly among general practitioners, to enhance knowledge and awareness of modern technologies through continuous education. Underused techniques in Croatia include rubber dams, magnifiers, lasers, and CBCT.

A Comparative Analysis of the Quality of Root Canal Fillings of In Vivo Studies Conducted in Saudi Arabia and Worldwide: A Systematic Review

Aim

Root canal treatment (RCT) is a common procedure practiced daily by dentists worldwide. The current systematic review aimed to evaluate and compare clinical studies on the quality of root canal fillings (RCFs) carried out by dentists with different levels of experience conducted worldwide with those conducted specifically in Saudi Arabia (SA).

Materials and Methods

A full literature search was conducted in Clarivate Analytics' Web of Science, Elsevier's Scopus, Embase, CINHAL, and PubMed, without a restriction to studies published before January 2015. Also, a manual search was carried out by checking papers that may have been missed during the electronic search. The following keywords were used: [(quality of root canal filling(s)) OR (quality of root canal obturation)) and dental practitioners as (general dental practitioners; final year students; endodontist; specialist) AND (root canal obturation) OR (endodontic treatment)]. Parameters of the quality of RCFs, such as length, density, and taper, were assessed and counted.

Results

A total of 13 worldwide and nine SA studies were included in this review, published between 2015 and 2023. Molars were the most treated teeth, at 42.3% and 40.2% for the worldwide and SA studies, respectively. Cases treated by final year students had the highest percentage, at 60.0% for both study groups. The percentages of acceptable quality, with regard to the length, density, and taper of RCFs, were 70.9%, 77.6%, and 84.3%, and 73.2%, 64.6%, and 67.8% for the worldwide and SA studies, respectively.

Conclusion

The overall acceptable quality of RCFs was marginally higher in worldwide studies than in SA studies. Both prevalences can be considered as good, which indicates that the quality of RCFs is moving in the right direction.

Effect of Orthodontic Treatment on the Outcomes of Endodontically Treated Teeth: A Cone-Beam Computed Tomography Analysis

INTRODUCTION

Often there is the need of moving endodontically treated teeth. Orthodontic movement may have no effect on the prognosis of teeth with root canal treatment (RCT). To verify this subject, we evaluated the effect of orthodontic movement on the prognosis of RCT teeth using cone-beam computed tomography (CBCT) and further explored the influence of orthodontic movement on the prognosis of RCT teeth with and without apical periodontitis (AP).

METHODS

This retrospective study was conducted by evaluating 169 RCT teeth of 100 patients who had undergone fixed orthodontic treatment. AP was assessed and classified using the CBCT periapical index. Univariate analysis of RCT outcome was performed for the total RCT group, RCT without AP group and RCT with AP group. Multivariate logistic regression was performed for the total RCT group and RCT without AP group, respectively, but not for the RCT with AP group. Variables related to the prognosis of RCT were included, such as age, gender, tooth position, RCT quality, coronal restoration quality, periodontal condition, orthodontic traction distance, and orthodontic rotation angle.

RESULTS

The orthodontic traction distance and rotation angle were not significantly correlated to the RCT outcomes, regardless of the presence of AP. Among the total RCT group, teeth with unqualified RCT (odds ratio = 3.42, P = .004) and inadequate coronal restoration (odds ratio = 4.40, P = .031) had a lower success rate. Of the 97 RCT teeth without AP, unqualified RCT was a risk factor for treatment failure (odds ratio = 3.55, P = .041). Of the 72 RCT teeth with AP, the univariate analysis showed that RCT quality were significantly related to the outcome (P = .042).

CONCLUSIONS

Orthodontic movement had no effect on the prognosis of RCT teeth regardless of the presence of AP.

GIRFT and Measuring Outcomes in MCNs: endodontics in 646 teeth treated in Tier 2 (Primary Care) and Tier 3 (Secondary Care) settings in England

AIM

This paper aims to assess the complexity, quality and outcome of endodontic treatment provided in Managed Clinical Networks (MCNs) in England to understand if we are "getting it right first time" (GIRFT).

METHODS

In a convenient sample of endodontic treatments provided between May 2011 and April 2017, the complexity of teeth treated, the quality of treatment procedure, the radiographic appearance of root fillings, as well as clinical and radiographic healing were retrospectively assessed using records taken as part of treatment. Trained, calibrated examiners independently scored radiographs using previously published scoring systems.

RESULTS

646 teeth were followed up for 24.7 months (standard deviation [SD] 17.08). The average age of those patients treated was 46.7 years (SD 15.38) with 48.3% being male. Of teeth treated, 70.4% were of complexity level 3. 88.2% of teeth were asymptomatic, and 80% demonstrated complete radiographic healing. Procedural errors inhibited achieving correct working length and taper, with more voids within root canal fillings. When patency filing was reported as being carried out, complete radiographic healing was more likely.

CONCLUSIONS

It is possible to collate outcome data in the NHS system, especially if there is provision for ongoing follow up and time allocated for collection of data. Endodontic treatment provided within primary and secondary care settings are of high quality, with outcomes being better with single operators carrying out high volumes of endodontic treatment.

Biological response to endodontic treatment in one versus two-visit: a systematic review and meta-analysis of animal studies

OBJECTIVES

To perform a systematic review of animal studies that compared the histopathological characteristics between teeth with apical periodontitis after endodontic treatment in one or two visits.

MATERIALS AND METHODS

This systematic review was registered on the International Prospective Register of Systematic Reviews (PROSPERO) - CRD42022340849. Studies were collected from PubMed/MEDLINE, LILACS, EMBASE, Livivo, SciELO, Web of Science, Scopus, and Cochrane Library and manual and gray literature searches. Animal studies that evaluated histological characteristics after endodontic treatment of teeth with apical periodontitis in one or two visits were included. Risk of bias analysis of the included studies was performed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. Data synthesis of the included studies with quantitative data was performed, and meta-analysis was conducted with the Comprehensive Meta-Analysis software, using the random effects model and odds ratio (OR).

RESULTS

Eighteen studies met the inclusion criteria (Kappa = 0.891). Meta-analyses indicated values in inflammatory infiltrate intensity with effect size of 5.5% (95% CI: 0.020-0.148; p < 0.001), periodontal ligament thickness: 25.6% (95% CI: 0.134-0.487; p < 0.001), dentin resorption: 13% (95% CI: 0.015-1.141; p = 0.066), cementum resorption: 7.1% (95% CI: 0.015-0.325; p = 0.001), bone resorption: 1.4% (95% CI: 0.002-0.130; p < 0.001), mineralized tissue resorption: 42.8% (95% CI: 0.110-1.671; p = 0.222), biological apical sealing: 13.1% (95% CI: 0.055-0.314; p < 0.001), and presence of microorganisms: 10.3% (95% CI: 0.014-0.747; p = 0.025).

CONCLUSIONS

When considering animal studies, the two-visit endodontic treatment, using calcium hydroxide-based intracanal medication, resulted in better biological repair characteristics.

CLINICAL RELEVANCE

A two-visit endodontic treatment with calcium hydroxide-based intracanal medication yields superior histopathological outcomes.

Methodologies used for testing the sealability of endodontic temporary fillings in vitro: A narrative review

Introduction

The ability of the temporary filling to seal endodontic access cavities may be crucial for the success of endodontic treatment. Numerous in vitro studies have investigated the sealability of the temporary fillings used in endodontic treatments. However, in vitro sealability studies have been criticized for their inconsistent results and questionable clinical relevance. Some journals have imposed moratoriums on publishing such studies to encourage researchers to test their validity and clinical relevance. Since the implementation of this moratorium, little progress has been made in this field. To further encourage researchers to investigate the reliability of these studies, this review presents an overview of the methodologies of studies that examine the ability of temporary filling materials to seal the endodontic access cavity in vitro and discusses the criticisms of these studies in detail.

Materials and Methods

PubMed, Scopus, and Embase electronic databases were searched to identify studies that tested in vitro the ability of temporary filling materials to seal endodontic access cavities. Only original articles published in English between 01/01/1970 and 28/02/2022 were included.

Results

The search yielded 551 results. After removing duplicates and excluding studies that did not meet the inclusion criteria, 94 studies were included in this review.

Conclusion

Although clinical studies may be the best way to test the performance of temporary fillings, the ethical importance of conducting preliminary in vitro studies is undeniable. It seems that questioning the reliability of in vitro sealability studies is not based on sufficient scientific evidence and that the inconsistencies in the results of these studies may be due to differences in the methodological and clinically relevant variables between them, rather than due to their unreliability.

Endodontic Outcome of Root Canal Treatment Using Different Obturation Techniques: A Clinical Study

OBJECTIVE

To evaluate the clinical outcome of root canal treatment by obturation technique, root canal filling quality, and tooth- and patient-related variables.

METHODS

This clinical study investigated the endodontic outcome of 114 teeth treated between the years 2009 and 2012. Three different obturation methods were used: (1) adhesive obturation using the continuous wave of condensation technique with Resilon® (CWR), (2) matching-taper single-cone technique with gutta-percha and AH Plus® (SCGP), and (3) matching-taper single-cone technique with gutta-percha and GuttaFlow® (SCGF). Pre- and postoperative periapical radiographs were performed to detect the presence of endodontic lesions (PAI classification) and to assess the quality of both the obturation and the restoration. Tooth- and patient-related data were collected.

RESULTS

The overall endodontic success rate was 75.4% after a mean observation period of 6.3 years. There were no significant correlations between the type or overall quality of obturation and the treatment outcome. Teeth with preoperative lesions had the highest odds ratio (factor of 4.98) for endodontic failure. Tooth- and patient-related variables had no significant effect on endodontic outcome.

CONCLUSIONS

The preoperative periapical status of teeth requiring endodontic treatment was a substantial prognostic factor for endodontic outcome, whereas the type of obturation material or technique did not affect it.

The effect of periapical lesion size on the success rate of different endodontic treatments: a systematic review and meta-analysis

INTRODUCTION

This systematic review evaluated the effect of periapical lesion (PL) size on the success rate of different endodontic treatments, including root canal treatment (RCT), non-surgical retreatment (NSR), and apical surgery (AS).

METHODS

Cohorts and randomized controlled trials investigating the outcomes of endodontic treatment of permanent teeth with PL and its size were identified electronically through Web of Science, MEDLINE, Scopus, and Embase databases. Two reviewers independently conducted the study selection, data extraction, and critical appraisal process. The quality of the included studies was evaluated using the Newcastle-Ottawa Scale and the 11-item Critical Appraisal Skills Program checklist for randomized controlled trials. The success rates of the endodontic treatments (small lesions and large lesions) were estimated using the rate ratios (RRs) with an associated 95% confidence interval (CI).

RESULTS

Out of 44 included studies, 42 were cohort, and 2 were randomized controlled trials. Thirty-two studies had poor quality. For the meta-analysis, five studies in RCT, 4 in NSR, and 3 in AS were considered. The RR of the endodontic treatment success in PLs was 1.04 in RCT (95% CI, 0.99-1.07), 1.11 in NSR (95% CI, 0.99-1.24), and 1.06 in AS (95% CI, 0.97-1.16). Only sub-group analysis of long-term follow-up of RCT showed a significantly higher success rate in small lesions than in large lesions.

CONCLUSIONS

Considering the quality of studies and variation in outcomes and size classification, our meta-analysis demonstrated that the PL size had no significant effect on the success rate of different endodontic treatments.

Global research trends on photodynamic therapy in endodontics: A bibliometric analysis

BACKGROUND

Photodynamic therapy (PDT) is an adjunctive treatment that aims to inactivate microorganisms through an oxidative reaction produced by irradiating a photosensitizing agent. The quest for improved root canal disinfection has sought supplementary methods when performing chemomechanical procedures. From this perspective, PDT protocols were proposed as an auxiliary approach in endodontics. Thus, the aim of this study was to investigate publication metrics and research trends related to this scope.

METHODS

This review is reported in accordance with the PRISMA 2020 recommendations. Two blinded and independent reviewers systematically searched five electronic databases until December 2021. The acquired bibliometric parameters were analyzed through descriptive statistics and graphical mappings with VOSViewer software.

RESULTS

The search retrieved 342 studies from 84 journals originating from 33 countries. About 85% of the included studies were published over the last decade. Most of the available evidence is laboratory-based (74.5%), and the main clinical outcomes evaluated were microbiological load reduction and postoperative pain. Mayram Pourhajibagher is the researcher with the most publications as the first author (n = 16). Tehran University of Medical Sciences carried out the highest number of studies (n = 29), and Photodiagnosis and Photodynamic Therapy is the journal that most published on the theme (n = 111).

CONCLUSIONS

This bibliometric analysis mapped and discussed the scientific progress and publication metrics in PDT in endodontic research. Additionally, future perspectives were highlighted and should focus on discovering new photosensitizer agents, standardizing optimal photoactivation protocols, and conducting more clinical-oriented research.

Outcomes reporting in systematic reviews on non-surgical root canal treatment: A scoping review for the development of a core outcome set

BACKGROUND

Studies related to non-surgical root canal treatment are amongst the most frequently performed clinical studies in endodontics. However, heterogeneity in reporting outcomes and lack of standardization is a significant challenge to evidence synthesis and guideline development.

OBJECTIVES

The aims of the present scoping review were to (a) identify outcomes reported in systematic reviews evaluating non-surgical root canal treatment; (b) identify how and when the reported outcomes were measured; (c) assess possible selective reporting bias in the included studies. The information obtained in this study should inform the development of a core outcome set (COS) for non-surgical root canal treatment.

METHODOLOGY

Structured literature searches were performed to identify systematic reviews on non-surgical root canal treatments published in English between January 1990 and December 2020. Two reviewers undertook study selection and data extraction. Outcomes were categorized according to a healthcare taxonomy into five core areas (survival, clinical/physiological changes, life impact, resource use, and adverse events). The outcome measurement tools and length of follow-up were recorded.

RESULTS

Seventy-five systematic reviews were included, of which 40 included meta-analyses. Most reviews reported on physiological and clinical outcomes, primarily pain and/or radiographic assessment of periapical status, and a variety of measurement tools and scales were used. Few reviews focused on tooth survival, life impact, resources, and adverse events. The heterogeneity amongst the reviews was large on all parameters. Less than 40% of the reviews assessed the risk of selective reporting.

DISCUSSION

Overall aims of the included reviews were highly heterogenic; thus, outcomes and how they were measured also varied considerably. Patient-centred outcomes and the use of resources were rarely reported on.

CONCLUSIONS

Most studies reported on physiological and clinical outcomes, in particular pain and/or radiographic healing. Measurement tools, scales, thresholds, and follow-up periods varied greatly within each outcome, making comparison across studies complicated. Less than 40% of the reviews assessed risk of selective reporting; thus, selective bias could not be ruled out. The presented information on reported outcomes, measurement tools and scales, and length of follow-up may guide the planning of future research and inform the development of a COS for non-surgical root canal treatment.

The outcome of endodontic treatment using an enhanced infection protocol in specialist practice

Objectives This study aims to determine the outcome of primary root canal treatment with specific enhanced infection control protocol. The secondary aim was to compare percentages of successful outcomes in this study with a previous study undertaken by the same operator using both periapical radiograph (PR) and cone beam computed tomography (CBCT).Materials and methods Root canal treatment of 110 teeth in 95 patients carried out by a single operator using an enhanced infection control procedure (disinfection of gutta percha before obturation, changing of gloves after each intraoperative radiograph and also before the start of the root canal obturation). PR and CBCT scans of 94 teeth in 87 patients were assessed 12 months after completion of primary root canal treatment and compared with their respective pre-treatment (diagnostic) PR and CBCT scans. Healing was assessed by a consensus panel consisting of two calibrated examiners. Comparison of the PR and CBCT images for 'healed' and/or 'healing' outcomes was performed using McNemar's test.Results The 'healed' rate (absence of periapical radiolucency) was 89.4% using PR and 78.7% for CBCT (p <0.046). This rate increased to 95.7% for PR and 92.6% for CBCT when the 'healing' group (reduced size of periapical radiolucency) was included (p <0.046).Conclusion The frequent changing of gloves during the course of endodontic treatment and disinfection of gutta percha points before obturation, together with the use of contemporary rotary files, resulted in a high success rate of primary root canal treatment compared to similar clinical studies conducted previously.

Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

A critical analysis of research methods and experimental models to study intracanal medicaments

In order to ensure predictable decontamination of the root canal system, chemo-mechanical preparation of the root canal space is sometimes supplemented with the use of intracanal medication. As microbial control of the root canal space is fundamental to the resolution of apical periodontitis, root canal disinfection strategies haven been researched intensively. The use of intracanal medication as a supplementary step to the chemo-mechanical preparation of the root canal space is one of them. Because of the costs and limitations of clinical research it is relevant and common practice to first evaluate alternative or new root canal disinfection modalities in laboratory studies. This involves the simulation of a root canal infection in a laboratory model, on which different disinfection strategies can be tested. When modelling the infected root canal, different levels of infection can be discriminated: suspended bacteria, microbial biofilms and infected dentine. This review describes the experimental models associated with these infection levels and critically appraises their value and methodological details. Suggestions for relevant research methods and experimental models are given, as well as some good practices for laboratory-based microbiological studies.

A Scoping Review of 4 Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies-Part 2: Outcome Measures

INTRODUCTION

Inconsistencies in the definitions of endodontic outcome terminology jeopardize evaluations of proposed interventions and patient care quality. This scoping review aimed to provide groundwork to develop a set of basic outcomes in endodontics.

METHODS

We performed a comprehensive literature search for randomized controlled trials, cohort studies, case-control studies, and case series (≥10 patients) published after 1980 with patients ≥10 years of age with any preoperative pulpal and periapical diagnosis in permanent teeth requiring nonsurgical root canal treatment, retreatment, or apexification. Abstracted data on outcome assessment methods, assessors, and domains were reported after univariate and bivariate analyses.

RESULTS

Treatment outcomes were evaluated radiographically (88%) or clinically (73%). Although 2-dimensional radiography exceeded 3-dimensional radiography, the use of the latter has increased since 2010, mostly for nonsurgical retreatments. Of 19 identified outcomes, 5 were most frequent: success (168 studies, 40%), radiographic healing (128 studies, 30%), survival (of an asymptomatic tooth [48 studies, 12%] or of a procedure code in administrative databases [31 studies, 7%]), pain assessment (14 studies, 3%), and quality of life (11 studies, 3%). Clinician-centered outcomes have been most frequently studied since the 1980s (71%), in academic settings (76%), and using a prospective design (45%). Patient-centered outcomes were reported in 19% of studies before 2010 and 30% since 2010. They were more common among retrospective studies (49%).

CONCLUSIONS

Patient-centered outcome measures are lacking in endodontic studies. The state of available research can provide a baseline for the development of a core outcome set in endodontics, which should represent the important patient-centered outcomes in conjunction with well-validated clinician-centered outcomes.

A retrospective three-dimensional assessment of the prevalence of apical periodontitis and quality of root canal treatment in Mid-West Indian population

Introduction

This study aims to report a retrospective observation of the prevalence of apical periodontitis (AP) and quality of root canal treatment in cone-beam computed tomography (CBCT) scans among the Mid-West Indian population.

Materials and Methods

A total of 1229 CBCT scans were obtained across different CBCT centers in western India. After the exclusion criteria, those that were included were divided into broadly two groups - those that were filled and those that were unfilled. Various parameters were taken into account such as AP, length of the root canal filled, and coronal filling.

Results

There were a significantly higher percentage of nonfilled canals. Poor filling quality, inadequate coronal restoration, and also missed extra canal were significantly associated with AP. Both males and females showed higher presence of AP in the nonfilled teeth than filled ones (X2 - Chi square value M = 612.156, P < 0.00001, X² F = 1032.9092, P < 0.00001).

Conclusion

(1) The inadequacy of the filling of the root length was a contributory factor to the higher prevalence of AP among the study population. (2) The density of the filling and the quality of the coronal filling also significantly affected the successful outcome of the root canal treatment.

Evaluation of the sealer/gutta-percha ratio on sets of root section surfaces of some extracted teeth sealed using the cold lateral condensation technique

Canal filling must be well adapted to the walls of the root canal to prevent bacterial infiltration. Endodontic seals play an essential role in ensuring tightness, without which the canal filling would suffer infiltrations. This study aimed to evaluate the areas occupied by the two components of the canal filling, as well as the sealer/gutta-percha ratio in the root canals of the maxillary central incisors after their filling using the cold lateral condensation technique with gutta-percha. Thirty extracted upper central incisors were rotatably prepared with ProTaper Universal up to F3 and sealed using the cold lateral condensation technique with gutta-percha. After setting the sealer, the roots of the teeth were sectioned perpendicularly to 1 (L1), 3 (L3), 6 (L6), and 8 (L8) mm from the apex. The surface of the sections was analyzed with a Leica EZ4D stereomicroscope and photographed at two magnification orders: 10x and 25x. The areas corresponding to the gutta-percha, sealer, gaps, and root canal were expressed in pixels using the ImageJ software, version 1.50i. The difference in the representation of sealer areas, gutta-percha and voids was statistically significantly different for all four sections analyzed. The best adaptation of the canal obturation was observed in L1 and L3. The gutta-percha area was statistically significantly higher than that of the sealer for the L1, L3, and L6 levels, while the sealer/gutta-percha ratio recorded the lowest value at the L3 level (0, 30) and the highest at its L8 (0.70) level, without registering statistically significant differences regarding the area at the four analyzed levels. The voids were mostly absent or recorded a minimal percentage area (<1%). Cold lateral condensation of gutta-percha has led to a good adaptation of gutta-percha to the root canal wall, with a small amount of sealer, especially to the sections made at 3 mm from the apex. Given the limitations of this study, we noted that the voids were few – observed in the 6 and 8 mm sections – and were negligible in many cases.

Photodynamic Inactivation of an Endodontic Bacteria Using Diode Laser and Indocyanine Green-Loaded Nanosphere

Apical periodontitis, an inflammatory lesion causing bone resorption around the apex of teeth, is treated by eradicating infectious bacteria from the root canal. However, it has a high recurrence rate and often requires retreatment. We investigated the bactericidal effect of antimicrobial photodynamic therapy (aPDT)/photodynamic antimicrobial chemotherapy (PACT) using indocyanine green (ICG)-loaded nanospheres coated with chitosan and a diode laser on a biofilm of Enterococcus faecalis, a pathogen of refractory apical periodontitis. Biofilm of E. faecalis was cultured in a porcine infected root canal model. ICG solution was injected into the root canal, which was then irradiated with a laser (810 nm wavelength) from outside the root canal. The bactericidal effect was evaluated by colony counts and scanning electron microscopy. The result of the colony counts showed a maximum 1.89 log reduction after irradiation at 2.1 W for 5 min. The temperature rise during aPDT/PACT was confirmed to be within a safe range. Furthermore, the light energy transmittance through the root was at a peak approximately 1 min after the start of irradiation, indicating that most of the ICG in the root canal was consumed. This study shows that aPDT/PACT can suppress E. faecalis in infected root canals with high efficiency.

Long-Term Follow-Up of Nonsurgical Endodontic Treatments Performed by One Specialist: A Retrospective Cohort Study about Tooth Survival and Treatment Success

Background

The main aim of the retrospective cohort study was to evaluate tooth survival after the endodontic treatment over a period of more than 20 years. Moreover, success of the treatment and the correlation between baseline parameters and the outcomes were analyzed, and causes were recorded.

Materials and Methods

Clinical records (including radiographs) of subjects treated with endodontic procedures (both primary and secondary (nonsurgical retreatment)) were collected and analyzed, covering a period of up to 29 years. Type of the treatment, technique, adequacy of treatment performed, presence of baseline radiolucency, and symptoms at baseline were recorded. Moreover, failure (presence of radiolucency 2 years after treatment) and tooth extraction data and causes of them were recorded. Outcomes were explored by using survival analysis (Kaplan-Meier estimates and survival table analysis) and regression analysis (Cox regression).

Results

A total of 2,679 endodontically treated teeth were included in the analysis. After 20 years from the treatment, the cumulative survival rate for primary and secondary treatments was 84.10% (80.99%-87.21%) and 89.79% (86.68%-92.90%), respectively. No differences were found between primary and secondary treatments or with regard to the technique adopted. The presence of periapical radiolucency was correlated to higher odds of tooth extraction.

Conclusions

Despite the limitations of the study, we can assume that the proportion of retained endodontically treated teeth was significantly high over a long-term period.

Management of Root Fenestration Using Buccal Decortication and Guided Tissue Regeneration: A Case Report and 3-dimensional Analysis

The management of patients with apical fenestration and clinical symptoms has always been limited to apical root resection and placement of the root tip within the bony crypt. This result would often present resolution of clinical symptoms based on a few case studies. In this case report, we present a case in which apical resection alone did not resolve the patient's discomfort; on the contrary, it resulted in further bone loss and persistence of clinical symptoms. A corrective surgery was performed with the use of guided bone regeneration in conjunction with decortication of the cortical plate to induce bleeding. The patient symptoms resolved within a few weeks after the surgery, and the follow-up scan showed apical root coverage. Three-dimensional analysis was performed to compare the bony changes between the 2 surgeries and showed a significant amount of bone gain of around 200 mm³ and a 2-mm linear bone gain opposite the distobuccal root. The case presents a conservative approach to manage root fenestration of the buccal plate without further compromising the root apex.

Outcome of Root Canal Treatments Provided by Endodontic Postgraduate Students. A Retrospective Study

The aim of this study was to assess the preoperative, intraoperative, and postoperative factors that influenced complete periapical healing in teeth that underwent primary root canal treatment (RCT), in patients treated by postgraduate students in endodontics. Factors were retrieved and compared with the periapical status during the follow-up visit. Healing was considered as the absence of clinical and radiological symptoms. Variables significantly associated by the chi-squared test were included in a logistic regression model (LRM). Preoperative factors associated with healing were: American Society of Anesthesiology (ASA) status (p = 0.01); the absence of preoperative pain (p = 0.04); positive response to pulp tests; when the RCT cause was caries, pain, abscess, or sinus tract; probing depth <4 mm; the absence of mobility; absence or <4 mm periapical lesion (p < 0.01). In the LRM, the factors included were: absence or <4 mm periapical lesion; probing depths <4 mm; RCT caused by caries, pain, abscess, or sinus tract; the tooth was not a bridge abutment. Postoperative factors were: teeth with direct restoration; teeth that did not act as a support for a fixed prosthetic restoration; the favorable condition of the coronal restoration (p < 0.01). In the LRM, only the status of the coronal restoration was included. Preoperative conditions and the adequate fit of the coronal restoration influenced the outcome of RCT.

Impact of orthodontic treatment on the integrity of endodontically treated teeth

AIM

The purpose of this study was to evaluate the periapical status of endodontically treated teeth and the integrity of endodontic treatment before and after orthodontic treatment.

MATERIALS AND METHODS

This retrospective study was conducted by evaluating 128 teeth with root canal treatment (RCT). The teeth were obtained from 72 patients (23 males, 49 females) who had undergone fixed orthodontic treatment. Panoramic radiographs were taken and were evaluated before the start and after the completion of orthodontic treatment. Apical periodontitis (AP) was evaluated by the periapical index (PAI) and the probability index (PRI) of periapical bone destruction. Other variables related to the quality of root canal fillings were included, such as RCT quality index, length, and homogeneity, and coronal restoration.

RESULTS

According to the PRI, the proportion of teeth with periapical bone destruction was significantly higher after orthodontic treatment. Overall, there was no significant change in the PAI scores after orthodontic treatment. However, the quality of the endodontic treatment moderated the change in the PAI score, as well as the change in the PRI. There was no significant increase in PAI and PRI scores after orthodontic treatment for adequately treated teeth. However, the risk for periapical lesions and bone destruction after orthodontic treatment was significantly increased for teeth receiving inadequate endodontic treatment compared with those receiving adequate endodontic treatment.

CONCLUSION

Increased PAI and PRI after orthodontic treatment correlated with the quality of endodontic treatment.

Pooled analysis of 1-year recall data from three root canal treatment outcome studies undertaken using cone beam computed tomography

AIM

To provide an estimate of the proportion of successful outcomes of primary and secondary root canal treatments (retreatments) determined by periapical radiographs and cone beam computed tomography (CBCT), a pooled analysis of the data collected from three previous prospective clinical outcome studies was undertaken.

METHODOLOGY

The analysis pooled the 1-year results for 354 teeth, including 123 primary treatments and 231 retreatments. All root canals were instrumented with ProTaper Universal and filled using a warm vertical condensation technique. Comparisons of favourable results between root canal treatments and retreatments and between different tooth types were made using chi-square/Fisher's exact test.

RESULTS

The overall percentage of favourable results was 91% using periapical radiographs and 80% for CBCT (P < 0.001). With CBCT, the percentage of favourable results for primary treatments (84.7%) was not significantly different (P = 0.316) from that of retreatments (77.9%). When assessed by tooth group, the overall percentage of favourable results with CBCT was 75.5%, 90.6% and 91.1% for molar, premolar and anterior teeth, respectively. When CBCT is used to assess the outcome, the proportion of favourable outcomes in molars was significantly lower than that of premolars and anterior teeth (P < 0.05). Teeth with root fillings terminating more than 2 mm short of the radiographic apex had less favourable outcomes (73%) compared to long (83%) and adequate root filling length (84%).

CONCLUSIONS

The proportions of favourable outcomes of primary root canal treatments and retreatments assessed with CBCT were lower when compared to periapical radiographs, and also lower than those historically reported by periapical radiograph-based outcome studies. Considering the very high favourable outcome of anterior teeth and premolars compared to molar teeth, future studies assessing the effect of new materials and techniques on the outcome of root canal treatments should be based on preoperative and postoperative CBCT images, and focus on molar teeth.

Apical periodontitis in southern Estonian population: prevalence and associations with quality of root canal fillings and coronal restorations

Background

Apical periodontitis (AP) is an inflammatory disease around the apex of a tooth root. Reported prevalence of AP ranges from 27% to 83% while the data about most post-Soviet countries are still missing. Knowing the prevalence of AP within a certain population helps to plan the treatment need and evaluate the success of endodontic interventions. We aimed to collect data about prevalence and determining factors of AP for the first time in Estonia.

Methods

The cross-sectional study included 6552 patients (age 35.5±19.2 years). Radiographic examination was applied to investigate the prevalence of AP and quality of endodontic treatment.

Results

AP was diagnosed in 54.7% of subjects. Endodontically treated teeth were present in 58.2% of subjects. Periapical finding was present in 44.6% of endodontically treated and in 30.8% of untreated teeth.

Out of 181,495 teeth, 52.7% were intact. AP was diagnosed in 6.3% of teeth, 6.9% of teeth were endodontically treated.

Risk factors for AP included caries (OR = 2.30), male gender (OR = 1.44), too short (OR = 1.76) or too long root canal filling (OR = 2.51), root canal filling of low density (OR = 1.61) while not orthodontic appliance. Lower AP risk was associated with restoration of the tooth – filling (OR = 0.45), crown (OR = 0.34) and bridge (OR = 0.33).

Conclusions

AP is highly prevalent in Southern Estonian population. Most cases are associated with root canal-treated teeth. The overall quality of root canal fillings tends to be low, consistent with the mediocre outcome of treatment. Considerable efforts are required to improve the standards of endodontic treatment.

Electronic supplementary material

The online version of this article (10.1186/s12903-017-0429-7) contains supplementary material, which is available to authorized users.

Uncertain Decision-Making in Primary Root Canal Treatment

OBJECTIVES

A systematic review of literature was conducted to compare the success and survivability of primary root canal interventions.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta Analyses protocol was adopted in this study to systematically assess and report systematic reviews related to success or survival or failure rates of primary root canal interventions. MEDLINE and Cochrane Oral Health Library were both searched by using specific search terms to identify relevant literature, until June 2016. The search was augmented by handsearching. Then, the quality of the included systematic reviews was assessed by using the Revised Assessment of Multiple Systematic Reviews (RAMSTAR) protocol.

RESULTS

Only 9 systematic reviews were identified. The RAMSTAR scores of the included reviews ranged from 43/44 to 29/44. Nevertheless, the later reviews did not provide sufficient evidence or statistically significant evidence to support any of the interventions used during primary root canal treatment. In addition, a number of key steps during primary root canal treatment, such as types of dental files, root canal instrumentation techniques, orthograde obturation materials, and techniques, were not assessed by systematic reviews.

CONCLUSION

The current status of evidence related to the success and survivability of primary root canal interventions is lacking. This puts dentists under marked degrees of uncertainty. Consequently, patients are potentially exposed to health care risks. It is then essential to develop tailored methods and tools for decision-making under uncertainty to aid both dentists and patients engaged in primary root canal treatment.

In Vivo and In Vitro Effectiveness of Rotary Nickel-Titanium vs Manual Stainless Steel Instruments for Root Canal Therapy: Systematic Review and Meta-analysis

INTRODUCTION

This systematic review evaluated the effectiveness of nickel-titanium (NiTi) rotary files compared to stainless-steel (SST) hand files.

METHODS

An electronic search was performed on Medline, EMBASE, CENTRAL and Scopus databases up to February 2016. An additional hand searching was performed in 13 journals. The studies were classified according to study type and the outcome variables. Two reviewers independently applied eligibility criteria, extracted data, and three reviewers independently assessed the quality of the evidence of each included study according to The Cochrane Collaboration's procedures. A meta-analysis was performed whenever it was possible.

RESULTS

The electronic and hand search strategies yielded 1155 references of studies after removal of duplicates. Four clinical studies (two prospective and two retrospective studies) and 18 in vitro studies (on extracted teeth) were included for the qualitative synthesis after full-text evaluation of the eligible studies. The overall level of methodological quality of the studies included can be considered inadequate. Only one clinical study was judged at low risk of bias, whereas most non-clinical studies had a low risk of bias. Three meta-analyses, based on a very limited number of studies, could be performed. Each meta-analysis contained two studies. Of these, one meta-analysis was based on clinical studies.

CONCLUSIONS

The results of this systematic review suggested that NiTi rotary instruments were associated with lower canal transportation and apical extrusion when compared to SST hand files, whereas both groups had similar outcomes in terms of success of therapy, amount of residual bacteria, and cleansing ability after treatment. However, due to the limited evidence available, these results should be interpreted with caution. Consequently, more randomized control trials using standardized protocols are needed in order to provide more solid recommendations.

Feasibility of Cone-beam Computed Tomography in Detecting Lateral Canals before and after Root Canal Treatment: An Ex Vivo Study

INTRODUCTION

The study objective was to evaluate the effectiveness of cone-beam computed tomographic (CBCT) imaging for the detection of lateral canals (LCs) in endodontically treated premolars.

METHODS

Two evaluators classified 80 extracted premolars into 2 groups based on the absence (n = 40) or presence (n = 40) of LCs according to micro-computed tomographic analysis. The extracted teeth were fixated in a human mandible and scanned with CBCT imaging. Subsequently, each tooth was endodontically treated, and CBCT scans were repeated. Three experienced examiners evaluated all images randomly. Receiver operating characteristic curves were compared using the McNemar test, and sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were obtained.

RESULTS

The area under the receiver operating characteristic curve values were 0.58 and 0.49 before and after root canal treatment, respectively. These values were statistically significantly different (P < .001). Before root canal treatment sensitivity, specificity, positive predictive value, and negative predictive value were 55%, 52%, 55%, and 56%, whereas after root canal treatment the values were 33%, 61%, 46%, and 48%, respectively.

CONCLUSIONS

LC detection in nontreated teeth presented low accuracy, whereas among treated teeth CBCT imaging showed no efficacy. The results suggest that CBCT imaging is not an effective diagnostic tool for LC detection.

Common Operative Procedural Errors and Clinical Factors Associated with Root Canal Treatment

Abstract Operative procedural errors must be well analyzed in order to avoid influence negatively the root canal treatment (RCT) prognosis. The successful RCT prevents tooth loss and avoids pain and apical periodontitis. This review aimed to categorize common operative procedure errors and clinical factors associated with RCT. Based on this, will be approached common errors of procedures within the clinical operative sequence: endodontic treatment planning, pulp and periapical disease diagnosis, anaesthesia, access cavity preparation, isolation with rubber dam, root canal preparation, root canal filling and retreatment, restoration of endodontically treated teeth, postoperative pain, follow up of endodontically treated teeth. The professional must remind that in each phase of RCT an operative error may have adverse implication on prognosis, and these errors characterize risk factors to failure. The knowledge of probable operative procedural errors and its consequences are essentials to avoid future problems to the tooth health.

Endodontic Treatment Outcomes

The primary goal of conventional endodontic treatment is prevention and/or elimination of apical periodontitis for both mature permanent teeth and immature teeth with an open apex. Besides these goals, the objectives of endodontic treatment of immature teeth include preservation of pulp vitality and often further root maturation. Robust criteria for outcome assessment are an essential determinant for any measure of treatment success for both mature and immature teeth.

A Comparative Chemical Study of Calcium Silicate-Containing and Epoxy Resin-Based Root Canal Sealers

Objective. The present study assessed the chemical elements in two novel calcium silicate-containing root canal sealers, BioRoot RCS and Well-Root ST, compared to a calcium silicate-containing root canal sealer that has been on the market for several years, MTA Fillapex, and epoxy resin-based sealer AHPlus. Material and Methods. The sealers were mixed and manipulated according to the manufacturers' instructions. Twelve cylindrical molds (inner diameter 4 mm; height 3 mm) were placed on a glass petri dish and packed with the materials. The dish was transferred to an incubator. After 72 h the molds were examined by scanning electron microscopy and energy dispersive X-ray microanalysis. Results. BioRoot RCS and Well-Root ST had high peaks of calcium, zirconium, oxygen, carbon, silicon, and chlorine. Well-Root ST also had sodium, magnesium, aluminum, and titanium peaks. MTA Fillapex and AHPlus had carbon, oxygen, calcium, titanium, and bismuth peaks. A silicon peak was also observed for MTA Fillapex, and zirconium and tungsten peaks for AHPlus. Conclusion. BioRoot RSC had the highest degree of purity. The clinical implication of metals contained in the other sealers needs to be investigated.

Healing outcomes of root canal treatment for C-shaped mandibular second molars: a retrospective analysis

Objectives

This study aimed to evaluate the healing rate of non-surgical endodontic treatment between C-shaped and non-C-shaped mandibular second molars.

Materials and Methods

Clinical records and radiological images of patients who had undergone endodontic treatment on mandibular second molars between 2007 and 2014 were screened. The periapical index scoring system was applied to compare healing outcomes. Information about preoperative and postoperative factors as well as the demographic data of the patients was acquired and evaluated using chi-square and multinomial logistic regression tests.

Results

The total healing rate was 68.4%. Healing rates for the mandibular second molar were 70.9% in C-shaped canals (n = 79) and 66.6% in non-C-shaped ones (n = 117). The difference was not statistically significant.

Conclusions

The presence of a C-shaped canal in the mandibular second molar did not have a significantly negative effect on healing after treatment. Instead, proper pulpal diagnosis and final restoration were indicated as having significantly greater influence on the healing outcomes of C-shaped and non-C-shaped canals, respectively.