Outcome of endodontic treatment – the elephant in the room

Endodontic treatment of chronic apical periodontitis ameliorates systemic inflammation and restores impaired cellular responses to insulin in an in vitro model

INTRODUCTION

A growing body of research supports an association between periapical inflammation and an increased risk of developing systemic diseases. There is currently no scientific evidence to support a causal effect of inflammation on the onset of insulin resistance (IR) in patients with apical periodontitis (AP). The aim of this in vitro study was to evaluate any association between AP and levels of serum inflammatory factors potentially associated with the onset of IR, and to investigate any the effect of root canal treatment (RCT) on these systemic inflammation markers and restoring on the response in vitro to insulin.

METHODS

A total of 27 control subjects and 27 patients with AP were enrolled. Patients with AP underwent RCT and were followed-up 6 and 12 months post-treatment. ELISAs were used to evaluate plasma serum levels of pro-inflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The human pancreatic epithelioid carcinoma cell line (PANC-1) was used to assess t The response in vitro to insulin was assessed by measuring glucose consumption in a human pancreatic epithelioid carcinoma cell line (PANC-1) treated with sera from healthy and AP subjects.

RESULTS

At baseline AP was associated with significantly higher levels of IL-1, IL-6, and IL-8 in the serum of untreated (AP) patients with AP vs controls (p<0.001). Glucose consumption decreased in pancreatic cells incubated with baseline serum from patients with AP, in a manner proportional to total cytokines amount. Notably, endodontic treatment was associated with reduced levels of cytokines (p<0.001) and improved response to insulin in AP group (p<0.001).

CONCLUSIONS

Our findings suggest that AP may promote inflammatory-driven IR in an in-vitro model, and that RCT may ameliorate inflammatory mediators in vivo and the cellular response to insulin in vitro.

Root canal re-treatment with gutta percha - which techniques influence success?

OBJECTIVE

A systematic review and meta-analysis of the literature was carried out assessing the success rate of root canal retreatment using gutta percha.

DATA SOURCES

Four of the largest databases were used to identify existing literature with no date or language restrictions. PubMed, Cochrane, ScienceDirect, Scopus and other additional sources were searched. Grey literature was also reviewed.

STUDY SELECTION

Two authors, with Master's degrees in endodontics and with extensive university teaching experience, were selected to screen the databases to identify suitable studies. In case the authors were not able to agree during the study selection process, a third investigator was consulted. Specific inclusion and exclusion criteria were outlined and adhered to in the study selection. Two randomised controlled trials, seven single arm prospective studies and one single arm ambispective study published before the 10th of December 2022 were included. These studies evaluated the success of root canal re-treatment, obturated with gutta percha with at least a 1-year follow-up. Nine of the studies were published between 1998 and 2022. Seven studies were conducted in Europe, one in North America and one in Asia.

DATA EXTRACTION AND SYNTHESIS

Standard Cochrane methods to assess interval validity were used. Risk of bias in individual studies was assessed using The Newcastle-Ottawa quality assessment scale (NOS) for single-arm studies, and the Cochrane risk of bias tool (RoB2) was used for randomised controlled trials. Outcome measures were standardised as either success or failure of root canal retreatment. Success was classified into 2 different criteria: Strict criteria = absence of clinical signs and symptoms and radiographically normal periodontal ligament space; and Loose criteria = absence of clinical signs and symptoms and absence or reduction of apical radiolucency in the control radiograph. Statistical analysis was undertaken using R software and the Freeman-Turkey transformation was performed. Results were visualised using forest plots. Heterogeneity between studies was measured using the Cochrane Q test and I2 values.

RESULTS

Whilst following strict criteria, the success rate of non-surgical root canal retreatment obturated with gutta percha was 71% for 1-3 years follow-up (95% CI, 0.66-0.77) and 77% for 4-5 years follow-up (95% CI, 0.67-0.86). Heterogeneity was moderate (I2 = 61.4) and low (I2 = 0.0), respectively. Factors reducing the success rate of root canal re-retreatment under the strict criteria were older patients, mandibular teeth, molar teeth, the presence of a peri-apical radiolucency, teeth with a previous radiolucency, large peri-apical radiolucency's, higher initial periapical index scores and multiple visit-retreatments. Following the loose criteria, the success rate of non-surgical root canal re-treatment obturated with gutta percha was 87% for 1-3 years follow-up (95% CI, 0.79-0.93) with significant heterogeneity across the studies (I2 = 88.5%). Factors influencing the success rate under the loose criteria were large periapical lesions >5 mm and higher initial periapical index (PAI) scores.

CONCLUSIONS

Non-surgical root canal retreatment results in favourable outcomes. However, there are several factors which can result in a lower success rate: the presence and size of a periapical radiolucency, a higher initial PAI score, multiple-visit retreatments, and the size and position of the tooth.

The Limitations of Periapical X-ray Assessment in Endodontic Diagnosis-A Systematic Review

Diagnosis is a key aspect in endodontic treatment, in a decade where invasive interventions are misapprehended as social tendency instead of medical necessity. All diagnostic facets should be considered before intending the operative phase. Intraoral endodontic radiology-based diagnosis has been shown to be limited. Periapical X-ray is the most used endodontic imaging, yet it does not provide high accuracy. Traditionally, dentists have been trained to diagnose a cyst by certain aspects (size, shape and appearance); hence, an assumption that teeth are affected by "periapical cyst" were subjected to unnecessary extraction or apicoectomy. The aim of this systematic review is to critically appraise the publications that relate the histological diagnosis of a periapical lesion (considered the gold standard) to intraoral X-ray investigation. Ovid Medline, PubMed, ScienceDirect, Mendeley and Scopus were searched for English-language studies comparing periapical diagnosis obtained by using two techniques (histopathology and X-ray). Sixteen articles were included for the final analysis (qualitative and quantitative evaluation) out of which only two supported the statement that periapical diagnosis can be coherently assessed through periapical imaging. Although there is not enough evidence to deliver a definitive conclusion, there are many publications that refute the diagnosis of a cyst via periapical X-ray.

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.

Dentinal microcracks induced by endodontic procedures: A scientometric and bibliometric analysis

Background:

Due to the large number of publications relating the occurrence of dental microcracks to endodontic procedures, this bibliometric study evaluated the scientific pattern and trends in literature and provided an overview of scientific production in this context.

Aim:

To analyze, quantify, and characterize the scientific production and trends of published articles evaluating dentinal microcracks formation after endodontic treatment procedures between 2010 and 2020 using bibliometric indicators.

Materials and Methods:

Published articles were found by the search in the Medline (PubMed) and Scopus database using the combination of the following keywords: Dentinal crack OR Dentinal Microcrack OR Crack formation OR Dentin Defect AND Endodontic treatment OR Root canal preparation OR Canal Preparation OR Root canal treatment OR endodontic procedures. The search was also conducted in the Journal of Endodontics and International Endodontic Journal. After inclusion and exclusion criteria application, data from all studies included were collected.

Results:

Among the 556 results after the search, 45 studies were included and analyzed in this bibliometry. No trend was observed in terms of the increasing number of articles over time. Most of them used an in vitro design, compared the effect of different endodontic techniques/systems for root canal instrumentation on dentinal microcracks formation, and were conducted in Turkey, Brazil, and India. Journal of Endodontics and International Endodontic Journal were the main journals with a higher number of articles published. Interestingly, studies conducted with some funding did not lead to higher citation numbers. Moreover, a relevant proportion of studies did not consider the inclusion of control groups, baseline evaluation, or statistical analysis. Micro-CT was the main technique used to evaluate microcrack presence.

Conclusion:

Microcrack formation after the use of different endodontic techniques/systems has been constantly evaluated in the literature. There is a pattern of methodologies used, which may explain the concentration of these studies in specific journals and countries.

Supplementary solvent irrigation efficacy on filling remnants removal comparing XP-endo Finisher R vs IrriSafe

This study aimed to compare the efficacy of XP-endo Finisher R and IrriSafe, with a solvent mixture of Methyl ethyl ketone/Tetrachloroethylene (MEK/TCE), in the removal of root filling residues. Twenty-four human mandibular incisors were pair-matched by micro-computed tomography according to volume and aspect ratio. After retreatment, specimens were allocated to two experimental groups (n = 12), according to the supplementary instrument used. The volume of residual filling material after each irrigating step and the time for retreatment was calculated. Statistical analyses were carried out using Mann-Whitney test, with a significance level of 5%. The volume of initial root canal filling material between the groups was similar (p > 0.05). With the final irrigation protocol (NaOCl and EDTA) the volume of the filling remnants decreased significantly (p < 0.05) with no differences between IrriSafe or XP-endo Finisher R (p > 0.05). The additional solvent mixture MEK/TCE increased the efficiency of filling materials reduction, regardless of the agitating instruments employed, IrriSafe or XP-endo Finisher R (p < 0.05). There was no difference between the two groups regarding the time (p = 0.149). Both supplementary instruments were effective in the reduction of filling remnants. The additional step with a solvent mixture of MEK/TCE enabled a total recovery of patency and the achievement of cleaner canals, independently of the agitation instrument.

Outcome measures to assess the effectiveness of endodontic treatment for pulpitis and apical periodontitis for use in the development of European Society of Endodontology (ESE) S3 level clinical practice guidelines: a protocol

The European Society of Endodontology (ESE) is in the process of developing S3Level Clinical Practice Guidelines for the treatment of pulpal and apical disease for the benefit of clinicians and patients. In order to ensure a homogenous review process in the development of the clinical practice guidelines, it is essential that the core outcomes for all endodontic treatments are standardized and recommendations are made regarding minimum follow-up time specific to each outcome measure. In the absence of a recognized core outcome set in Endodontics, the current project aimed to follow an established consensus process to define the most appropriate clinician and patient-reported outcomes. As part of the project, recommendations will also be agreed regarding an acceptable minimum follow-up period for studies by literature review and group discussion. The selected outcome measures and follow-up periods will be used in subsequent systematic analyses of the literature to investigate the effectiveness of endodontic treatment to alleviate pulpitis and apical periodontitis. In this paper, previous reviews, ESE Guidelines and Position Statements were searched in order to compile a list of potentially important outcome measures for the treatment of pulpitis (working group 1), the nonsurgical treatment of apical periodontitis (working group 2), the surgical treatment of apical periodontitis (working group 3) and the regenerative treatment of apical periodontitis (working group 4). Initially, the two S3 guideline leads selected two independent senior clinical academics with experience of evidence-based dentistry to lead each of the four working groups forming a 10-member steering group. The working group leads in turn selected 32 academics with experience of evidence-based dentistry to lead the individual systematic reviews contained within the respective working groups. These 42 individuals make up the Guideline Development Group (GDG). Prior to the selected systematic reviewers commencing writing and submitting the review protocol, the complete list of outcome variables identified in this document will be ranked by the 42 members of the GDG in their importance to the individual patient using a 9-point Likert scale. A summary of the survey scores will thereafter be shared with the members of the group and the final list of clinician and patient-reported outcome measures rated as critical for decision making (7-9 on Likert scale by majority of survey participants) to guide systematic reviews will be consented and confirmed during an online meeting of the steering group. In this online meeting, another aspect with regard to meaningfulness of clinical trial results to be addressed in systematic reviews will be consented: length of follow-up. In order to develop high quality guidelines, it is suggested that the follow-up period after treatment should be related to the specific outcome measure being addressed; however, a minimum of one year for assessing the effectiveness of treatments for pulpitis and apical periodontitis should be considered. It is accepted, that selected research questions that focus on pain, swelling, medication taken or investigating diagnostic accuracy are likely to have shorter follow-up periods. As a result of the GDG consensus process, the outcome measures and length of follow-up will, alongside the use of standard instruments to assess the methodological quality of clinical trials and other comparative studies, be applied to all the commissioned systematic reviews that will inform the subsequent process when developing the ESE S3 Level Clinical Practice Guidelines.