Factors that affect the outcomes of root canal treatment and retreatment-A reframing of the principles

Environmental stimuli-responsive hydrogels in endodontics: Advances and perspectives

Stimuli-responsive hydrogels are smart and functional materials that respond to various environmental stimuli, including temperature, light, magnetic field, pH, redox, enzymes and glucose. This responsiveness allows for the controlled release of therapeutic agents encapsulated within the hydrogels, enhancing treatment precision, improving therapeutic outcomes and minimizing side effects. Such hydrogels show great potential in root canal disinfection, management of dental pulp inflammation and pulp regeneration, making them promising candidates for more personalized and effective endodontic treatments. This article provides an overview of the latest advancements in the design and application of stimuli-responsive hydrogels in endodontics, emphasizing their potential to revolutionize endodontic treatments. It also addresses current challenges and explores future directions in the field, aiming to inspire and motivate researchers to further engage in or intensify their efforts within this promising area of research.

A survey of cone beam computed tomography use amongst endodontic specialists in the United Kingdom

INTRODUCTION

The aim of this study was to investigate the applications of cone beam computed tomography (CBCT) amongst endodontic specialists in the United Kingdom (UK) via an online survey.

METHODS

An online invitation to take part in the survey was sent out to 306 specialist endodontists registered on the UK specialist register. The survey consisted of a series of questions associated with demographics, access and use of CBCT, utilization of dose optimization parameters, and frequency of use in different clinical scenarios.

RESULTS

In total, 202 respondents completed the survey (a response rate of 66.3%), 128 were male (63.4%), and 74 were female (36.6%). Of the 202 respondents, 174 (85.7%) used CBCT for diagnosis and/or management of endodontic problems. A CBCT scanner was on-site in 71.3% (n = 124) and 28.7% (n = 50) being off-site. A small field of view (FOV) was the prescribed scan in most cases (88.5%, n = 154/174). The cost of the CBCT scan was included in the assessment/treatment fee in 21.8% (38/174) of cases, with 78.2% (136/174) charged a separate fee for the scan. In total, 89.1% (155/174) respondents used CBCT 'often or always' for management of complex root canal anatomy, 87.4% (152/174) for root resorption, 84.5% (147/174) for periapical microsurgery, only 20.7% (36/174) of respondents would use CBCT to assess the outcome of treatment. Only 35.1% (61/174) of respondents would prescribe a CBCT scan for a pregnant patient and 78.2% (136/174) would take a CBCT scan for a paediatric patient. In total, 22.4% (39/174) of respondents did not report or request reports of their CBCT scans. Respondents chose to alter the exposure parameters depending on the patient's age or if the dentition was deemed extensively restored. Of the clinicians who incorporate CBCT into their practice, 93.7% (164/174) believe it improves the quality of the care they provide, and 93.6% (163/174) felt that the use of CBCT improves confidence in their diagnosis.

CONCLUSIONS

The use of CBCT amongst specialist endodontists in the UK is commonplace. However, usage does not appear to completely follow best practice guidance for certain clinical scenarios and highlights the need for further training in CBCT.

Effectiveness of microscope-assisted root canal treatment in permanent posterior teeth: a retrospective cohort study

OBJECTIVE

To evaluate the effect of microscope-assisted nonsurgical endodontic treatment on the clinical success rate in posterior teeth and to elucidate the interrelationship among various contributing factors.

MATERIALS AND METHODS

This retrospective cohort study included 337 teeth (from 301 patients) that underwent microscope-assisted root canal treatment (RCTx) and 298 teeth (from 256 patients) that underwent nonmicroscopic RCTx. All patients' electronic medical records and periapical radiographs were uniformly recorded. Strict and loose criteria were adopted to assess treatment success. Multiple logistic regression models were utilized to investigate the prognostic factors.

RESULTS

Significant differences were observed based on strict criteria regarding number of roots, number of canals, extra canal, swelling, sinus tract, palpation pain, deep and narrow pocket, apical lesion size, root resorption, secondary RCTx (20 RCTx), and periapical diagnosis (p < 0.05). Compared to nonapical lesion cases, the odds ratios of success in cases with preoperative apical lesions below 5 mm and at least 5 mm were 0.16 and 0.06 times, respectively (p < 0.001). The odds ratio of success for 20 RCTx was 0.35 times that of primary RCTx (10RCTx) (p < 0.001). "Apical lesion size," "treatment type," and "RCTx with aid of microscope" were significantly correlated (p < 0.001) based on strict criteria. "RCTx with aid of microscope" was significantly correlated (p < 0.05) based on loose criteria.

CONCLUSION

Compared with traditional RCTx, microscope-assisted RCTx in posterior teeth resulted in a 2.9-fold and 3.2-fold increase in positive outcomes based on strict and loose criteria, respectively.

CLINICAL SIGNIFICANCE

Microscope-assisted RCTx may help manage difficult root canal referral cases and provide a better prognosis.

Evaluation of Quality of Record-Keeping and Root Canal Therapy Performed by Two Predoctoral Cohorts

Objectives: A retrospective clinical audit was carried out to evaluate and compare the quality of record-keeping (QRK) and quality of root canal therapy (QRCT) performed by 4th-year and 5th-year predoctoral students. Methods: Electronic records and periapical radiographs of 702 root canal treated teeth performed by 4th-year and 5th-year predoctoral students from July 2018 to December 2021 were evaluated in compliance with standard European Society of Endodontology (ESE) and American Association of Endodontists (AAE) guidelines. Associations between the QRK and the QRCT were statistically analysed using the chi-square test (p < 0.05). Results: Overall acceptability of the QRK and the QRCT was 72.08% and 50.57%, respectively. The reference point of working length was the most common criterion not recorded (33.91%). No significant difference was observed in the QRK between 4th-year (76.05%) and 5th-year (69.70%) students (p = 0.226), as well as the QRCT between 4th-year (51.33%) and 5th-year (50.11%) students (p = 0.755). Acceptable root canal fillings were significantly higher in anterior teeth (57.48%) than in posterior teeth (47.54%) (p = 0.015). Satisfactory QRK was significantly associated with satisfactory QRCT (p = 0.046). Conclusions: Both predoctoral cohorts showed no difference in QRK and QRCT. However, QRK was better than QRCT. Comprehensive and accurate record-keeping positively impacted the QRCT.

The impact of passive ultrasonic irrigation on the bond strength of two different self-etch adhesives to human pulp chamber dentine: a laboratory investigation

OBJECTIVES

To evaluate the impact of passive ultrasonic irrigation on the micro-tensile bond strength of two different self-etch adhesive systems, including a universal one-step adhesive and a two-step adhesive system, to pulp chamber dentine compared to conventional syringe irrigation.

METHODS

Twenty-four extracted human mandibular first molar teeth were chosen according to strict criteria and mounted in epoxy resin blocks. Subsequently, the pulp chambers were exposed using an Isomet cutting machine. The specimens were numbered and assigned to four groups (6 teeth each) based on the canal irrigation method and the adhesive system used as follows: Conventional syringe irrigation in which a universal one-step self-etch adhesive system was applied (CSIU), conventional syringe irrigation in which a two-step self-etch adhesive system was used (CSIT), passive ultrasonic irrigation in which a universal one-step self-etch adhesive system was utilized (PUIU), and passive ultrasonic irrigation in which a two-step self-etch adhesive system was employed (PUIT). Following placement of the final restoration and submission to simultaneous thermo-mechanical cycling (artificial aging) equivalent to 6-month intra-oral aging, the teeth were sectioned and dentine/restoration beams were prepared. The micro-tensile bond strength was evaluated and the failure mode was defined, with a confirmatory evaluation of the dentine-resin interface using a scanning electron microscope. Statistical analysis was conducted using one-way ANOVA and Tukey's post hoc tests to compare irrigation regimens for each adhesive technique independently, while failure modes of each adhesive system were represented as the frequency for each irrigation method. The significance level was set at 5%, with a confidence interval (CI) of 95%.

RESULTS

The micro-tensile bond strength of composite resin restorations to pulp chamber dentine was reduced significantly with ultrasonic irrigation with more unfavorable failure modes compared to syringe irrigation (P < 0.0001), irrespective of the type of adhesive system used. The means of the micro-tensile strength for teeth treated with the two-step adhesive system were 26.1055 ± 4.7611 MPa and 16.0079 ± 3.7665 MPa for CSIT and PUIT, respectively. For teeth treated with the universal adhesive system, the mean for CSIU (20.1818 ± 3.8500 MPa) was significantly higher than that of PUIU (11.2090 ± 2.9928 MPa). The micro-tensile bond strength was significantly greater with the two-step adhesive system compared to the universal adhesive, regardless of the irrigation method (p < 0.05). An adhesive layer with varying thickness was noted in all groups, displaying distinct morphological features.

CONCLUSIONS

Within the limitations of the present laboratory investigation, ultrasonic irrigation may negatively affect the bond between composite resin restorations and pulp chamber dentine compared to conventional syringe irrigation. The two-step self-etch adhesive tended to achieve a stronger bond to pulp chamber dentine than the universal one-step self-etch adhesive.

CLINICAL RELEVANCE

While ultrasonic irrigation would be essential for effective root canal debridement and disinfection, it is imperative for clinicians to consider its potential adverse effects. This method may considerably impact the bond strength of composite resin restorations to the pulp chamber dentine, particularly when compared to conventional syringe irrigation. In root canal-treated teeth, a two-step self-etch adhesive system might be more effective in maximizing the bond strength to pulp chamber dentine than a universal adhesive system. However, these findings were concluded under the conditions of the present study and must be interpreted cautiously. Further research is recommended to validate these results and fully understand the clinical ramifications of ultrasonic irrigation on adhesive performance in different dental situations.

CLINICAL TRIAL NUMBER

Non-applicable. Conducting the current experiment was limited to the approval of the local Research Ethics Committee at the Faculty of Dentistry, Minia University, Egypt (Committee No. 106, Registration No. 910, Date: April 30, 2024).

Postoperative Pain and Periapical Healing after Endodontic Treatment Using Pachymic Acid-Modified Epoxy Resin Root Canal Sealer: A Double-Blind Randomized Controlled Trial

INTRODUCTION

This study evaluated the effect of adding pachymic acid (PAC) to an epoxy resin root canal sealer (AH Plus) on the postoperative pain and periapical (PA) healing in teeth with necrotic pulp and apical periodontitis.

METHODS

Fifty single-rooted teeth with necrotic pulp and apical periodontitis were randomly assigned to two groups according to the sealer (n = 25), AH Plus (AHP) and AHP modified with PAC (AHP/PAC). Endodontic treatment was conducted in 2 visits, with calcium hydroxide as an intracanal medicament. Pain scores were recorded using visual analog scale at baseline, 24 hours and 7 days postoperatively. PA healing was evaluated by measuring lesion size at baseline and postoperatively at 3, 6, 9, and 12 months using digital radiograph. Cone-beam computed tomography (CBCT) was used to assess PA lesion volume and PA volume index score at baseline and 1-year follow-up. Statistical analysis was done using Mann-Whitney U test.

RESULTS

Postoperative pain in AHP/PAC was significantly lower than AHP at 24 hours (P = .03), with no pain in either group at day 7. PA lesion size at 3-month follow-up showed no significant difference (P = .10) between the groups, but a significant reduction was seen in AHP/PAC at 6-, 9-, and 12-months (P < .001). A significant reduction in lesion volume and PA volume index score score were also seen in AHP/PAC at 1-year follow-up (P < .001).

CONCLUSIONS

The addition of PAC to AHP decreased the immediate postoperative pain and improved the long-term healing of PA lesions, with a marked reduction in lesion size from 6-month onward.

Success and failure of endodontic treatment: predictability, complications, challenges and maintenance

The fundamentals of successful endodontic treatment are an awareness of the aetiology of the disease process and an understanding of factors that affect outcome. This paper aims to outline the prognostic factors found in the endodontic outcome literature to facilitate options appraisal and predictable treatment delivery. We will discuss pre-treatment, treatment and post-treatment factors. In summary, the significance of infection control throughout treatment, provision of an adequate coronal seal and appropriate restoration of the root-filled tooth are highlighted.

Vital pulp therapies in permanent teeth: what, when, where, who, why and how?

The dentine-pulp complex is a unique organ that provides nourishment to the dentine and supports the tooth's innervation and defence system. Preserving its health is a key aspect of minimally invasive dentistry. Vital pulp therapies (VPTs), as defined by the European Society of Endodontology, are 'treatment strategies aimed at maintaining the health of all or part of the pulp'. These therapies are particularly useful when pulp inflammation, caused by caries or trauma, threatens pulp vitality and may otherwise lead to necrosis and the need for invasive treatment. VPTs offer several advantages, including the retention of the pulp's immunological functions, maintenance of the structural integrity of the tooth, reduced patient pain and simplified treatment protocols. Additionally, these therapies lower the costs and inconvenience associated with more invasive treatments, benefiting both patients and society. A range of protocols and key factors promoting successful outcomes have been described to guide dental practitioners in adopting VPTs where appropriate. Future considerations for pragmatic research and implementation in primary care are essential to create a sustainable use of VPTs, thus promoting better oral health.

Management of the endodontic-periodontal lesion

Endodontic-periodontal lesions (EPLs) develop due to the various pathways that allow microbial migration between these two compartments. The authors review the historical and current research on the aetiology, diagnostic pathways, prognostic factors and management strategies for EPLs, emphasising a multidisciplinary approach to managing EPLs. This paper aims to guide clinicians in managing these challenging cases with a combination of endodontic and periodontal therapies.

Characteristics of Teeth and Patients Receiving Root Canal Treatment in National Dental PBRN Practices: Comparison Between Endodontist and General Dentist Practices

PURPOSE

To describe and compare patient and tooth characteristics determined prior to treatment among those receiving root canal treatment (RCT) from general dentists (GD) versus endodontists within the National Dental Practice-Based Research (PBRN) Network.

METHODS

This National Dental PBRN study involved 153 practitioners (104 GDs and 49 endodontists) who used a consecutive enrollment strategy to enroll patients. Practitioners recorded details about pre-operative tooth characteristics. Prior to RCT, patients provided data about their socio-demographic, medication use, temporomandibular disorder (TMD), and psycho-social characteristics. We describe the overall prevalence of these characteristics and compare them by provider type.

RESULTS

1,723 patients were enrolled; 788 by GDs and 935 by endodontists. Endodontists treated higher proportions of female, non-Hispanic white, better-educated patients, patients from the Midwest and Southwest regions, and molar teeth compared to GDs. GDs saw a higher proportion of patients from the Northeast and whose teeth had a probing depth of 5 mm or more. All of these characteristics were independently and significantly (at p <.05) associated with provider type. Endodontists were more likely than GDs to see patients with TMD symptoms in bivariate comparisons, but their patient groups were similar with regard to treatment outcome expectation, dental fear, depression, and anxiety.

CONCLUSION

Significant differences exist between endodontists and GDs in patient demographics, tooth characteristics, and treatment patterns, with endodontists treating more molars, female, non-Hispanic white, and educated patients, while GDs manage more cases involving antibiotics use and teeth with deep probing depths, highlighting variations in referral patterns and treatment accessibility.

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.

Retreatment or replacement of previous endodontically treated premolars with recurrent apical periodontitis? An 8-year historical cohort study

OBJECTIVES

The study evaluated previously-endodontically-treated premolars affected by periapical lesions and/or secondary caries requiring a multidisciplinary decision between (non-surgical) retreatment or extraction and implant replacement over an 8-year minimum follow-up.

MATERIALS AND METHODS

The decision-making was performed among a pool of patients attending a University Dental School. All patients presented at least one failing previously endodontically treated premolar. Recorded parameters were: structural conditions (residual coronal-structure, caries), periodontal and endodontic status (CEJ-MBL, initial-PAI, post-presence). Two experienced operators made the decision-making and classified teeth as retreatable and restorable (Endo-group) or suitable for extraction and implant replacement (Implant-group). Logistic regression and Cox-proportional-hazard analyses with clustered-standard-errors compared baseline-characteristics and treatment-outcomes. Odds-ratios (ORs) with 95% confidence-intervals (CIs) were reported for baseline-characteristics. Hazard-ratios (HRs) expressed the association of treatment-groups with time-to-event.

RESULTS

Ninety-six patients (n = 124 premolars) were enrolled (49 M;47 F; mean-age 53.1 ± 11.6 years). The decision-making splitted 54.8% treatments to Endo-group (n = 68) and 45.2% to Implant-group (n = 56). The 8-year survival were 85.1% for Endo-group and 98.2% for Implant-group. The 8-year success were 80.5% and 93.9%. The HR from Cox regression favored Implant-group (HR = 0.12, P = 0.049). The Endo-group showed the highest number of critical complications (15%) due to fractures, despite the healing of lesions. Implant-group had a higher percentage of minor prosthetic complications (14%).

CONCLUSIONS

Endo-group demonstrated higher percentage of critical complications compared to Implant-group during the follow-up. Root fractures were accounted as main responsible, while periapical disease did not affect healing, survival and clinical longevity.

CLINICAL SIGNIFICANCE

Insufficient crown structure was the major parameter associated with root fracture. In these cases, implant replacement strategy represented an adequate therapy justified by the higher success compared to root canal retreatment.

Association between Dental Variables and Hashimoto's Disease: A Retrospective Cohort Study

OBJECTIVES

 The present study aimed to compare dental, endodontic, and periodontal status in patients with Hashimoto's disease and healthy patients, as well as to disclose the relation between dental variables and Hashimoto's disease.

MATERIALS AND METHODS

 The research included 85 patients affected by Hashimoto's thyroiditis (analyzed group) and 85 healthy patients (control group). The two groups were matched according to age and gender. Data regarding patients' health status was acquired from their medical records. Data regarding dental, endodontic, and periodontal status were acquired from patients' dental records and digital panoramic radiographs.

STATISTICAL ANALYSIS

 Since a nonnormal distribution of data was detected, a median and interquartile range were used as a measure of central tendency and dispersion. Mann-Whitney U test and chi-squared test were used to test the differences between the groups. Multiple linear regression analysis and logistic regression analysis were used to test the association of the data.

RESULTS

 Healthy participants had significantly higher median number of teeth with secondary caries (median 2; interquartile range 1-3) when compared with participants with Hashimoto's disease (median 1; interquartile range 0-2; p < 0.001). Periodontal disease was present in significantly more participants with Hashimoto's disease than healthy patients (68.2% vs. 45.9%; chi-square = 7.779; p = 0.005). The presence of Hashimoto's disease increased the risk of periodontal disease presence three times (odds ratio [OR] = 3.14; 95% confidence interval [CI] 1.38-7.15; p = 0.007). The presence of periodontal disease increased the risk of Hashimoto's disease presence by 2.5 times (OR 2.54; 95% CI: 1.36-4.73; p = 0.004).

CONCLUSION

 With the study limitations in mind, it may be concluded that a positive relationship between periodontal disease and Hashimoto's thyroiditis exists.

Does achieving apical patency increase postoperative pain during endodontics?

DATA SOURCES

PubMed, Scopus, Embase, Web of Science, Cochrane Library, and gray literature up to May 2023. Twelve studies were included for meta-analysis.

STUDY SELECTION

Two authors screened databases to identify suitable studies, with a third investigator resolving disagreements. Inclusion criteria were randomized controlled trials (RCTs) involving individuals without systemic diseases, who underwent root canal treatment in a permanent tooth with or without apical patency. Outcomes included pain, number of patients with pain and analgesic use. Exclusion criteria included patients who had undergone tooth extraction, incomplete data reports and studies which were not RCTs. There were no limits on publication language. A search of PubMed, Scopus, Embase, Web of Science, Cochrane Library, and gray literature from Google Scholar, ProQuest, OpenAire, and BASE identified 92 articles until May 2023. After removing 42 duplicates, 50 article full texts were assessed. Ultimately, 12 studies were included, seven of which were new relative to previous systematic reviews.

DATA EXTRACTION AND SYNTHESIS

Data were analysed using RevMan 5.4 software. Dichotomous categorical data were analysed through the Cochran-Mantel-Haenszel test, with the inverse variance method used for continuous data. Following assessment of heterogeneity with the χ2 test, fixed- or random- effects modeling was used. Pain scores were reported within one week by ten studies, but three were excluded from meta-analysis due to methodological issues.

RESULTS

Studies involving participants aged 14-65 years, with pulp necrosis, apical periodontitis, or pulpitis, were included for analysis. Irrigation solutions varied from saline to sodium hypochlorite (2.25-5.25%), EDTA, citric acid, or chlorhexidine. Types of teeth treated included molars and anterior teeth. All studies used a 10# K-file for apical patency and various hand and nickel-titanium instruments for canal preparation. Generally, there was slightly reduced post-operative pain reported through the maintenance of patency. This was evident in the initial post-operative period of 24 h (OR = 1.69, P = 0.002), 1-day (MD = -1.69, P = 0.03) and 2-days (MD = -0.85, P = 0.04), but became non-significant over the remainder of the 7-day monitoring period. There was no significant difference in analgesic use between groups (OR = 0.82, P = 0.42). Studies were classified into three groups based on quality: four high quality with low risk of bias; three moderate quality with some concerns; and five low quality with high risk of bias. Evidence quality varied; pain scores on days 1 and 2 were of low quality, with very low quality for 12 h and days 3-6. High heterogeneity and imprecision were noted, especially in pain measurements and analgesic use.

CONCLUSIONS

The meta-analysis indicates that during the initial post-operative period, apical patency significantly reduces postoperative pain. However, the findings should be interpreted cautiously due to high heterogeneity and variable evidence quality. Given that apical patency is seen as desirable for achieving the biological aims of endodontic treatment, the fact that it also appears to reduce post-operative pain helps to align patient reported outcome measures with traditional measures indicating success.

Position statement on longitudinal cracks and fractures of teeth

This position statement is a consensus view of an expert committee convened by the European Society of Endodontology (ESE). The statement is based on current clinical and scientific evidence as well as the collective reflective practice of the committee. The aim is to provide clinicians with evidence-based, authoritative information on the aetiology, clinical presentation, and management of cracks and fractures that typically manifest along the long axis of the crown and/or root.

A service evaluation assessing the root canal referral and treatment pathway within the Royal London Dental Hospital

Aim Within the National Health Service (NHS) England, dental hospitals are tasked with assessing and managing complex root canal treatments (RCTs) referred from various service providers. The aim of this service evaluation was to investigate the root canal treatment and retreatment (RCreT) output, case complexity designation and referral pathways to the Royal London Dental Hospital.Methods Data were collected and analysed on non-surgical RCTs completed between 1 April 2021 to 31 March 2022, including the number of completed treatments, reason and origin of referrals, referral-to-treatment timelines and complexity of treatments.Results In total, 339 teeth met the inclusion criteria, with external referrals (n = 198) taking an average of 47 weeks from referral to treatment commencement compared to 16 weeks for internal referrals (n = 141). Maxillary incisors and first permanent molars were most commonly referred, with anatomical challenges (33.5%), RCreT (32.2%) and trauma (18%) being the most common reasons. Treatment was completed within an average of 2.7 appointments, with a high proportion of complexity Level 2 and 3 cases being completed.Conclusions The RCT output was shown to be increasing within the service. External referrals are taking longer to be seen and treated compared to NHS targets and internally referred patients; although, further information is needed to understand the exact cause of this. Allocation of treatment complexity appeared to be in line with the clinician's skill set and experience level, taking an average of 2.7 appointments to complete treatment. Further information on the number of referrals, available consultations and clinic space would provide additional insight into the efficiency and pressures of the service.

Investigating root and canal morphology of anterior and premolar teeth using CBCT with a novel coding classification system in Saudi subpopulation

Understanding root canal morphology is essential for successful endodontic treatment. This study aimed to investigate morphological variations in root and canal systems of anterior and premolar teeth across different age groups and genders in a Saudi Arabian subpopulation using a novel classification system. A total of 3573 maxillary and mandibular anterior and premolar teeth in 209 patients were examined using cone-beam computed tomography (CBCT) in a Saudi subpopulation. The number of roots was identified, and root canal configurations were classified according to Ahmed et al. coding system (Int Endod J 50(8):761-770, 2017). Demographic data including gender (male and female) and age (divided into 6 groups-10-20, > 20-30, > 30-40, > 40-50, > 50-60, > 60-70) were recorded. The Chi-square test was used for statistical analysis, and the significance level was set at 0.05 (P = 0.05). Results showed that maxillary and mandibular central incisors, lateral incisors, and canines predominantly exhibited the 1TN1 configuration. Maxillary first premolars had a higher prevalence of double-rooted variants with code 2TN B1 P1. Maxillary second premolars more frequently displayed the 1TN1-2-1 configuration. No significant gender and age differences were observed in maxillary anterior and premolar teeth (p > 0.05). A number of supplemental configurations such as 2TNB1-2P1, 3TN MB1 DB1 P1, and 3TN 1(MB1 DB1) P1 were noted in maxillary premolars. For mandibular anteriors, results showed no significant difference by gender, but for age, mandibular incisors showed more prevalence of complex canal configurations up to 40 years. However, the difference with other age groups (> 40-70 years) was not statistically significant (p < 0.05). For mandibular premolars, the code 1TN1 was observed in more than 90% of the teeth with no significant differences in gender and age groups (p > 0.05). Several supplemental configurations such as 1TN1-2-3, 1TN1-2-3-2, 2TN B1/L1, and 2TN 1B1/L1) were noted in mandibular first premolars. This study identified a wide range of root and canal anatomical variations in anterior and premolar teeth within a Saudi subpopulation. The findings revealed that while age influenced the complexity of root canal systems in mandibular incisors, no significant association between gender and canal complexity was observed. The Ahmed et al. classification system offered a detailed analysis of these complex variations, providing a clear understanding of the root canal morphology in this population.

A 4-year follow-up of root canal obturation using a calcium silicate-based sealer and a zinc oxide-eugenol sealer: A randomized clinical trial

AIM

This randomized clinical trial assessed the outcomes of nonsurgical root canal treatment (RCT), comparing a calcium silicate-based sealer (CSBS) with the single-cone technique (SC) with a zinc oxide-eugenol (ZOE) sealer and warm vertical compaction (WVC).

METHODOLOGY

Ninety-two single- and multi-rooted teeth were divided into two groups and treated using either the SC with BioRoot™ RCS (BIO) or WVC with Pulp Canal Sealer™ EWT (PCS). Teeth with apical periodontitis (AP) in both groups were further divided into BIOAP and PCSAP subgroups. Standardized instrumentation and disinfection protocols were followed. Periapical index (PAI) was recorded, and clinical and radiographic follow-ups were conducted at 1, 3, 6, 12, 24, and 48 months. Outcomes considered included success rate (under strict and loose criteria), extraction, length of filling, voids, and extrusion rate, as well as changes in PAI score from baseline. Outcome variables and prognostic factors were analysed using binary and multiple logistic regression at p < .05.

RESULTS

Sixty-seven teeth were included (recall rate, 73%). At 4-year follow-up, the overall success rates (BIO + PCS) were 89.6% by loose criteria and 83.3% by strict criteria. Subgroup success rates (BIOAP+PCSAP) were 88.5% by loose criteria and 80.4% by strict criteria. There were no significant differences between the groups in terms of success rate, extraction rate, length of filling, voids, or extrusion (p > .05). The pattern of PAI reduction was similar in both groups (p = .806).

CONCLUSION

Treatment using the SC-CSBS technique and the ZOE sealer with the WVC technique demonstrated a similar success rate.

Orifice barrier preferences for coronal restoration of root filled teeth by endodontists and other dental practitioners in Australia: A questionnaire survey

OBJECTIVES

To compare the use of orifice barriers (OB) in root-filled teeth (RFT) between specialist endodontic practitioners (SEP) and general and other specialist practitioners (GDP+), and identify common materials, reasons for selection, and techniques.

METHODS

An online survey was distributed to SEP and GDP+ practising in Australia. Demographic and multiple-choice questions relating to material selection and technique choices were asked to evaluate and relate usage patterns to practising and training backgrounds. Fisher's exact tests were undertaken to compare categorical variables across practitioner groups. Significance level was set at p<.05.

RESULTS

There were 457 eligible responses: 393(86%) GDP+ and 64(14%) SEP. Of 429 reporting endodontically treating or restoring teeth, 317(73.9%) placed OB; preferred depth of root filling removal by most (91.8%) was ≤ 2 mm, with more SEP preferring 2 mm than GDP+(p=.02). Preferred materials for OB were conventional and resin-modified GIC (GIC), resin composite materials (RC), Cavit™ and zinc polycarboxylate cement (ZPC). 'Ease of use' was a common reason among all practitioners for GIC and RC. Significantly more SEP(p<.001) chose ZPC in all teeth and more commonly because of 'Ease of use' for both posterior (p<.001) and anterior (p=.002) teeth. All ZPC-using SEP preferred using a paste-filler/lentulo spiral, significantly more than GDP+ for posterior (p<.001) and anterior (p=.002) teeth. Cavit™ was often chosen for 'Sealing ability'.

CONCLUSIONS

OB were widely placed by dental practitioners in Australia, with a small group of materials selected, most commonly for ease of use or sealing ability. The findings of this study suggest that further research should be undertaken to investigate the relative performance of these materials as OB and to inform the clinician's choices when restoring RFT.

The efficiency of single-session photobiomodulation on healing of periapical bone lesions using CBCT: a randomized clinical trial

As photobiomodulation is growing in the dental field the aim of this prospective, two-arm clinical trial was to assess the radiographic changes for chronic periapical bone lesions related to mandibular molars after primary root canal therapy with or without applying Diode laser on soft tissue. The samples were randomly divided into a Laser group and a mock laser (ML) group. Preoperative CBCT images were compared 12 months later with postoperative CBCT to gauge the changes in the volume of the bony lesion by two observers. The kappa coefficient was calculated to assess the intra-observer agreement. Data were presented as median, mean, and standard deviation (SD) values. For parametric data (age), a Student's t-test was used. Qualitative data (Gender) was presented as frequencies and percentages and then analyzed by Chi-square test. The Wilcoxon signed-rank test was used to compare CBCT measurements pre- and post-treatment. The significance level was set at P ≤ 0.05. The collected data in this study showed that there was no statistically significant difference between median volumes of the periapical lesion in the Laser and ML groups (P-value = 0.564, Effect size = 0.237) and (P-value = 0.452, Effect size = 0.310), respectively while, there was a statistically significant decrease in the volume of periapical lesion post-treatment within each group (P-value < 0.001). The size of the periapical bony lesion decreased significantly after conventional endodontic treatment whether Laser was applied or not. The study protocol was enrolled as NCT04311905 at www.clinicaltrials.gov database on (17/03/2020) after the approval of the Ethics Committee, Faculty of Dentistry, Ain Shams University (FDASURecID091703).

Clinical Outcomes and Complication Rates of Endodontically Treated Teeth with Fixed Dental Prostheses: A Retrospective Study

Background/Objectives: Endodontically treated teeth (ETT) often have significant structural damage and require multiple reinforcing methods during the reconstruction process. The aim of this study was to evaluate the complication rates of ETT with and without a post. Methods: The study investigated various clinical factors, including technical complications as well as biological complications. All patients who had previously received fixed dental prostheses (FDPs) were subjected to clinical and radiographical examinations during their follow-up visits. Clinical and radiographic assessments were performed to determine the cumulative survival rate, and life table survival analyses of FDPs in the presence of complications were performed. Results: A total of 287 ETT were evaluated in this study, in which 219 were placed in females and 68 in males, with an average follow-up time of 82.4 months. There were no significant differences between ETT with a post and ETT without a post regarding the complication rates. The complication rates of the FDPs without a post revealed a survival rate of 58% after 5 years, 44% after 10 years, and 29% after 15 years. On the other hand, the complication rates of the FDPs with a post revealed survival rates of 50%, 30%, and 21% after 5, 10, and 15 years, respectively. The Kaplan-Meier survival analysis showed no significant differences in the complication rates, regardless of the existing of the posts (p = 0.830). Conclusions: ETT restored with FDPs with or without a post can show similar complication rates in a long-term evaluation. Furthermore, the types of final restoration may not have an effect on the complication rate with ETT.

Finite element analysis of stress in mandibular molars repaired after fractured instrument removal

BACKGROUND

This study assessed stress distributions in simulated mandibular molars filled with various materials after the removal of fractured instruments from the apical thirds of the root canals.

METHODS

Finite element models of the mesial and distal root canals were created, where fractured instruments were assumed to be removed using a staging platform established with a modified Gates-Glidden bur (Woodpecker, Guangxi, P.R. China). Each canal was treated with different materials: Biodentine (Septodont, Saint Maur-des-Fosses, France), mineral trioxide aggregate (MTA), and gutta-percha. In addition to these, four control models were also created. In total, 14 models were generated and subjected to a 300 N force applied at a 45° angle to simulate the stress.

RESULTS

Model 1 (Biodentine) and 2 (Gutta-percha + Biodentine) showed the lowest stresses among mesial root canal models, whereas Model 5 (Gutta-percha) showed the highest. Among distal root canal models, Model 6 (Biodentine) and 7 (Gutta-percha + Biodentine) showed the lowest stresses, while Model 10 (Gutta-percha) showed the highest. In addition, Biodentine (Septodont) and Gutta-percha + Biodentine (Septodont) produced similar stress levels in both mesial and distal roots, while MTA and Gutta-percha + MTA led to increased stresses, especially in the distal root. Among the control models, the highest maximum von Mises stress values were in Model 13 and Model 14, which had a staging platform and were not filled with any root canal filling material, after the broken instrument was removed.

CONCLUSIONS

Biodentine (Septodont) may be preferable to MTA for filling staging platform cavities post-fractured instrument removal due to lower stress levels. Furthermore, calcium silicate-based materials alone or in combination with Gutta-percha showed similar stress levels, suggesting their potential use for root canal filling. All models demonstrated structural integrity within safe limits.

Expert consensus on pulpotomy in the management of mature permanent teeth with pulpitis

Pulpotomy, which belongs to vital pulp therapy, has become a strategy for managing pulpitis in recent decades. This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing long-term patient-centered outcomes. Pulpotomy is categorized into partial pulpotomy (PP), the removal of a partial segment of the coronal pulp tissue, and full pulpotomy (FP), the removal of whole coronal pulp, which is followed by applying the biomaterials onto the remaining pulp tissue and ultimately restoring the tooth. Procedural decisions for the amount of pulp tissue removal or retention depend on the diagnostic of pulp vitality, the overall treatment plan, the patient's general health status, and pulp inflammation reassessment during operation. This statement represents the consensus of an expert committee convened by the Society of Cariology and Endodontics, Chinese Stomatological Association. It addresses the current evidence to support the application of pulpotomy as a potential alternative to root canal treatment (RCT) on mature permanent teeth with pulpitis from a biological basis, the development of capping biomaterial, and the diagnostic considerations to evidence-based medicine. This expert statement intends to provide a clinical protocol of pulpotomy, which facilitates practitioners in choosing the optimal procedure and increasing their confidence in this rapidly evolving field.

Augmenting quality of life and mental health through the promotion of accessible root canal therapy

Root canal therapy (RCT) is an extremely safe, effective, and painless procedure that is crucial to save a tooth that would have been otherwise extracted. As patients with tooth infections present with severe pain and inability to carry out routine oral functions, RCT plays a vital role in improving the quality of life of the patients. The RCT procedure not only plays a crucial role in the relief of physical pain but also significantly contributes to mental well-being. After realizing the benefits of RCT in improving the quality of life and positive impact on the mental well-being of the patients, we anticipate that all patients must timely receive the therapy, but then that is not the case due to the presence of various challenges and factors. The presence of these barriers envisages the need for the formulation of comprehensive policies, expansion of community outreach activities, and education of patients to improve access to RCT. In conclusion, RCT has been associated with multiple benefits. There arises the need to overcome the identified barriers to ensure that RCT becomes more accessible for a wide range of patients needing essential dental services.

Efficacy of root filling removal from aged, minimally instrumented mandibular molars using a retreatment system combination

OBJECTIVE

This study evaluated the efficacy of the ProTaper Universal Retreatment system (PTUR) and XP-endo Finisher R instrument (XPFR) in removing 64-month-old root filling material from minimally-instrumented mandibular molar canals.

METHODS

Forty-eight root canals with Vertucci type II or IV configurations from 30 mandibular molars were instrumented to size 20/0.04 taper using Vortex Blue NiTi rotary instruments and irrigated with the GentleWave system. The canals were divided into three groups based on the root filling method: single-cone with AH Plus sealer (SA), single-cone with GuttaFlow 2 sealer (SG), and GuttaCore with AH Plus sealer (GA). Specimens were stored at 100 % humidity and 37 °C for 64 months. Retreatment consisted of PTUR instrumentation, followed by XPFR for canals with residual filling material. Micro-computed tomography was used to evaluate the volume of root filling material in the canals after 64 months of obturation, post-PTUR instrumentation, and after the supplementary XPFR approach.

RESULTS

No significant differences were observed in the volume of root filling material among the SA, SG, and GA groups (p > 0.05). After PTUR retreatment, the percentage of filling material removal, or remaining volume, did not significantly differ among the three groups (p > 0.05). However, supplementary XPFR instrumentation significantly reduced the remaining filling material in all groups. The PTUR and XPFR combination was the most effective in the SA and GA groups, followed by the SG group (p < 0.05).

CONCLUSION

The PTUR and XPFR retreatment system combination was more effective in removing root filling material from minimally-instrumented mandibular molars.

CLINICAL SIGNIFICANCE

The combined use of retreatment file systems improves efficacy of retreating minimally-instrumented mandibular molars by reducing residual filling material and enhancing canal cleanliness, with the potential to improve retreatment outcomes.

Outcomes and prognostic factors of endodontically treated teeth filled with calcium silicate- or epoxy resin-based root canal sealers: A retrospective cohort study

AIM

The objectives of this study were to compare the clinical outcomes of root canal treatment between calcium silicate-based sealer using the cold hydraulic condensation technique and epoxy resin-based sealer using warm vertical compaction and to identify the prognostic factors affecting the outcomes of both obturation techniques.

METHODOLOGY

Dental records and radiographs of the teeth that received root canal treatment with calcium silicate-based sealer using the cold hydraulic condensation technique or epoxy resin-based sealer using warm vertical compaction during 2015-2021 were selected using inclusion and exclusion criteria. The cases were matched between the two groups based on four factors: primary root canal treatment or retreatment, tooth type, periapical lesion and its size and extension of root canal filling. The success rates of root canal treatment between two sealers/obturation techniques were analysed. The incidence and resorption of extruded sealer were evaluated using the McNemar's test. Generalized estimated equations were used to evaluate any prognostic factors.

RESULTS

The median recall period of this study was 15 months. A total of 234 teeth, comprising 117 cases in each sealer/obturation group, were included. No significant difference was found in the success rates between the calcium silicate-based sealer using the cold hydraulic condensation technique group (91.5%) and the epoxy resin-based sealer using the warm vertical compaction group (94.9%). The incidence of sealer extrusion for the calcium silicate-based sealer (27.6%) did not significantly differ from that of the epoxy resin-based sealer (36.2%), with both sealers typically demonstrating no resorption at recalls. No prognostic factors related to the success rate of either technique were detected.

CONCLUSION

The study findings suggest no difference in the success rate between calcium silicate-based sealer and epoxy resin-based sealer. The study did not identify any prognostic factors that significantly influenced the outcomes of the endodontic treatments.

Development and evaluation of a deep learning segmentation model for assessing non-surgical endodontic treatment outcomes on periapical radiographs: A retrospective study

This study aimed to evaluate the performance of a deep learning-based segmentation model for predicting outcomes of non-surgical endodontic treatment. Preoperative and 3-year postoperative periapical radiographic images of each tooth from routine root canal treatments performed by endodontists from 2015 to 2021 were obtained retrospectively from Thammasat University hospital. Preoperative radiographic images of 1200 teeth with 3-year follow-up results (440 healed, 400 healing, and 360 disease) were collected. Mask Region-based Convolutional Neural Network (Mask R-CNN) was used to pixel-wise segment the root from other structures in the image and trained to predict class label into healed, healing and disease. Three endodontists annotated 1080 images used for model training, validation, and testing. The performance of the model was evaluated on a test set and also by comparison with the performance of clinicians (general practitioners and endodontists) with and without the help of the model on independent 120 images. The performance of the Mask R-CNN prediction model was high with the mean average precision (mAP) of 0.88 (95% CI 0.83-0.93) and area under the precision-recall curve of 0.91 (95% CI 0.88-0.94), 0.83 (95% CI 0.81-0.85), 0.91 (95% CI 0.90-0.92) on healed, healing and disease, respectively. The prediction metrics of general practitioners and endodontists significantly improved with the help of Mask R-CNN outperforming clinicians alone with mAP increasing from 0.75 (95% CI 0.72-0.78) to 0.84 (95% CI 0.81-0.87) and 0.88 (95% CI 0.85-0.91) to 0.92 (95% CI 0.89-0.95), respectively. In conclusion, deep learning-based segmentation model had the potential to predict non-surgical endodontic treatment outcomes from periapical radiographic images and were expected to aid in endodontic treatment.

Smear layer removal comparing conventional irrigation, passive ultrasonic irrigation, EndoActivator System, and a new sonic device (Perfect Clean System) by scanning electron microscopy: An ex vivo study

AIM

This study evaluated the smear layer removal provided by conventional, sonic, and ultrasonic irrigation techniques.

METHODOLOGY

Forty extracted human mandibular first premolars were selected and instrumented using the ProTaper Next System files and 2.5% sodium hypochlorite. Afterward, they were divided into 4 groups (n. 10) according to the irrigation technique used to perform the final irrigation with a chelating solution (17% EDTA): conventional irrigation (CI), passive ultrasonic irrigation (PUI), EndoActivator System (EAS), and Perfect Clean System (PCS). The smear layer removal was determined through a score after evaluating scanning electron microscope images (1.000x) obtained at 1, 5, 8, and 12mm from the working length (WL). Statistical analyses were carried out by the Kruskal-Wallis and Dunn's tests with a significance level of 5% (P < 0.05).

RESULTS

All irrigation techniques were unable to promote an effective smear layer removal at 1mm from the WL in comparison with the other locations (P < .05). At 5, 8, and 12mm from the WL, no statistically significant differences were observed among CI, PUI, EAS, and PCS (P > 0.05). At 12mm from the WL, statistically significant differences were only identified after comparing PCS and CI (P < .05).

CONCLUSION

The smear layer removal was only efficient at 5, 8, and 12 from the WL with no significant statistical differences among CI, PUI, EAS, and PCS (P > 0.05).

Unveiling the mechanical performance of partially replaced coronal restorations in root canal-treated teeth: an in-vitro study

OBJECTIVES

To compare the mechanical performance of partially replaced (repaired) intra-coronal restorations to totally replaced ones in root canal-treated teeth.

METHODS

Thirty maxillary second premolars were selected according to strict criteria, mounted on moulds, and had mesio-occluso-distal (MOD) cavities prepared. Resin composite restorative material was used to perform the initial restoration, followed by aging procedures using thermo-mechanical cycling fatigue to replicate six months of intraoral aging. The specimens were then randomly divided into two groups: a totally replaced restoration (TR) group (n = 15), which involved the preparation of a traditional endodontic access cavity after the complete removal of the pre-existing coronal filling; and a partially replaced restoration (PR) group (n = 15), which involved accessing the tooth through the pre-existing restoration without completely removing it. Root canal preparation and filling procedures were conducted, and the access cavity was sealed with a new resin composite restoration, followed by a new thermo-mechanical cycling aging procedure. Finally, the specimens were submitted to a static fracture test to measure specimen fracture strength and determine the failure mode pattern (repairable fracture or irreparable fracture). Chi-square and t-tests were used for statistical analysis.

RESULTS

Significant differences between the groups regarding their mechanical resistance were found. The average failure load of the TR group was 1115.13 N and 1330.23 N in the PR group (p = 0.002). Regarding the failure modes, the TR group exhibited eight irreparable fractures, while the PR group had four (p = 0.136).

CONCLUSIONS

Partially replaced restorations presented higher fracture strength and led to fewer irreparable fractures when compared to totally replaced restorations in root canal-treated teeth.

The use of 0.5% or 3% NaOCl for irrigation during root canal treatment results in similar clinical outcome: A 6-year follow-up of a quasi-randomized clinical trial

AIM

To evaluate the 6-year outcome of root canal treatment irrigated with 0.5% or 3% sodium hypochlorite (NaOCl).

METHODOLOGY

The baseline trial was designed as a quasi-randomized clinical trial. Patients referred for root canal treatment to an endodontic specialist clinic were recruited to the study (n = 298). The concentration of NaOCl was allocated quasi-randomized to 271 subjects (0.5% [n = 139], 3% [n = 132]). Bacterial sampling was performed immediately before root canal filling. Samples were cultured and evaluated as growth or no growth. Patients were invited to a clinical and radiological follow-up >5 years postoperatively. The clinical outcome measurements were tooth survival, cumulative incidence of endodontic retreatments, patients' assessment of pain, clinical findings and radiological signs of apical periodontitis (AP).

RESULTS

Tooth survival was 85.6% in the 0.5% NaOCl group and 81.1% in the 3% NaOCl group (p = .45). There was no record of retreatment in 94.4% in the 0.5% NaOCl group and in 92.2% in the 3% NaOCl group (p = .76). The percentage of asymptomatic cases were 87.8% in the 0.5% group and 85.3% in the 3% NaOCl group (p = .81). Absence of clinical signs of AP was seen in 86.6% in the 0.5% NaOCl group and in 83.6% in the 3% NaOCl group (p = .80). Absence of radiological signs of AP was seen in 74.0% in the 0.5% NaOCl group and 64.1% in the 3% NaOCl group (p = .20). Subjects with positive culture before root filling reported subjective pain with a significantly higher frequency as compared to negative-culture subjects (p = .014).

CONCLUSIONS

The use of 0.5% or 3% NaOCl for irrigation during root canal treatment resulted in similar clinical outcomes 5-7 years postoperatively. Persisting bacteria immediately before root filling may predict future episodes of subjective pain.

Single-cell RNA sequencing combined with proteomics of infected macrophages reveals prothymosin-α as a target for treatment of apical periodontitis

INTRODUCTION

Chronic apical periodontitis (CAP) is a common infectious disease of the oral cavity. Immune responses and osteoclastogenesis of monocytes/macrophages play a crucial role in CAP progression, and this study want to clarify role of monocytes/macrophages in CAP, which will contribute to treatment of CAP.

OBJECTIVES

We aim to explore the heterogeneity of monocyte populations in periapical lesion of CAP tissues and healthy control (HC) periodontal tissues by single-cell RNA sequencing (scRNA-seq), search novel targets for alleviating CAP, and further validate it by proteomics and in vitro and in vivo evaluations.

METHODS

ScRNA-seq was used to analyze the heterogeneity of monocyte populations in CAP, and proteomics of THP-1-derived macrophages with porphyromonas gingivalis infection were intersected with the differentially expressed genes (DEGs) of macrophages between CAP and HC tissues. The upregulated PTMA (prothymosin-α) were validated by immunofluorescence staining and quantitative real time polymerase chain reaction. We evaluated the effect of thymosin α1 (an amino-terminal proteolytic cleavage product of PTMA protein) on inflammatory factors and osteoclast differentiation of macrophages infected by P. gingivalis. Furthermore, we constructed mouse and rat mandibular bone lesions caused by apical periodontitis, and estimated treatment of systemic and topical administration of PTMA for CAP. Statistical analyses were performed using GraphPad Prism software (v9.2) RESULTS: Monocytes were divided into seven sub-clusters comprising monocyte-macrophage-osteoclast (MMO) differentiation in CAP. 14 up-regulated and 21 down-regulated genes and proteins were intersected between the DEGs of scRNA-seq data and proteomics, including the high expression of PTMA. Thymosin α1 may decrease several inflammatory cytokine expressions and osteoclastogenesis of THP-1-derived macrophages. Both systemic administration in mice and topical administration in the pulp chamber of rats alleviated periapical lesions.

CONCLUSIONS

PTMA upregulation in CAP moderates the inflammatory response and prevents the osteoclastogenesis of macrophages, which provides a basis for targeted therapeutic strategies for CAP.

In Vitro Microscopical and Microbiological Assessment of the Sealing Ability of Calcium Silicate-Based Root Canal Sealers

This in vitro study evaluated the sealing ability and microleakage of calcium silicate-based sealers compared to an epoxy resin-based sealer. One hundred twenty-five roots from anterior teeth were chemo-mechanically prepared and divided into four groups: AH Plus (AH), ProRoot MTA (PR), Medcem MTA (MC), and Total Fill BC Sealer/BC-coated gutta-percha (TF); n = 30. Confocal laser scanning microscopy was used to measure sealer penetration at three horizontal levels in 10 roots per group, while glucose leakage over 30 days was assessed in 20 roots. A lateral compaction technique was used for most groups, except for TF, which employed a single-cone method. Data were analyzed using Python with a Kruskal-Wallis test and Dunn's post hoc test. TF showed significantly greater penetration in the coronal and middle sections, while PR had the least penetration in the apical section. PR exhibited the highest canal circumference penetration, especially compared to MC and TF. Glucose leakage increased over time in all groups, with TF showing the highest permeability after 30 days. Overall, calcium silicate-based sealers PR, MC, and TF performed similarly to the epoxy resin standard AH, with all groups exhibiting decreasing penetration from coronal to apical and increased leakage over time.

Limitations, challenges and prospective solutions for bioactive glasses-based nanocomposites for dental applications: A critical review

Several nanomaterials have been recently used to overcome various challenges in the dental domain. Bioactive glasses, a class of bioceramics, with their outstanding properties including but not limited to their strong biocompatibility, antibacterial characteristics, and bioactivity inside the body's internal milieu have made them valuable biomaterials in a variety of dental domains. The utilization of nanomaterials has improved the performance of teeth, and the incorporation of bioactive glasses has the field of dentistry at an unsurpassed level in different categories such as esthetic and restorative dentistry, periodontics and dental implants, orthodontics, and endodontics. The current study discusses the most recent developments of the bioactive glasses' creation and implementation for dental applications, as well as the challenges and opportunities still facing the field. This work provides an overview of the current obstacles and potential future prospects for bioactive glasses-based nanocomposites to improve their dental uses. It also emphasizes the great potential synergistic effects of bioactive glasses used with other nanomaterials for dental applications.

Outcome of Nonsurgical Root Canal Retreatment of Teeth with Persistent Apical Periodontitis Treated with Foraminal Enlargement and 2% Chlorhexidine Gel: A Retrospective Cohort Study

INTRODUCTION

Nonsurgical root canal retreatment (NS-RCRT) becomes necessary when primary endodontic procedures fail. This study evaluates the efficacy of NS-RCRT using 2% chlorhexidine gel and foraminal enlargement techniques, aiming to assess whether these approaches enhance periapical healing outcomes and success rates compared to traditional NS-RCRT techniques reported in the literature.

METHODS

This retrospective cohort study analyzed 120 teeth diagnosed with persistent apical periodontitis, from 80 patients who underwent NS-RCRT between January 2014 and December 2018 at a specialist's private practice. Data were collected following the Preferred Reporting Items for Observational Studies in Endodontics 2023 guidelines. Periapical healing was evaluated using digital periapical radiographs by three calibrated examiners. The outcome of the treatment was analyzed through descriptive statistics and bivariate analyses, including the Chi-Square and Fisher's Exact tests. Treatment outcomes were deemed successful if they showed complete or incomplete repair and unsuccessful if no repair was observed.

RESULTS

The average follow-up period was 30 months. Under loose criteria, 92.50% (n = 111) of the teeth were categorized as successful, and 7.5% (n = 9) as unsuccessful. Bivariate analysis indicated that the radiographic restoration of apical transportation was the only factor that significantly influenced the outcome.

CONCLUSIONS

NS-RCRT performed in a single visit using the foraminal enlargement technique and 2% chlorhexidine gel demonstrated high success rates and may be an effective alternative to tooth extraction. This method promoted periapical healing and could significantly improve NS-RCRT protocols. Further prospective studies are recommended to corroborate these findings.

Effect of bioceramic-based and resin-based sealers on postoperative discomfort following root canal therapy: a systematic review and meta-analysis

Background

The aim of this systematic review and meta-analysis was to furnish evidence-based recommendations for the utilization of bioceramic-based and resin-based sealers in clinical endodontics, with a focus on reducing postoperative discomfort.

Methods

The investigation's methodology was registered on the International Prospective Database of Systematic Reviews (PROSPERO: CRD42022355506) and executed using the 2020 PRISMA protocol. Articles were selected utilizing the PICO technique and applying specific inclusion and exclusion criteria. Articles published between January 2000 and August 2022, PubMed, MEDLINE, and DOAJ were utilized as primary data sources. After the identification of studies, two autonomous reviewers evaluated the titles and abstracts, and data from qualifying studies were extracted.

Results

Nine published studies were included in this analysis. The findings indicate that there were no significant differences in the Visual Analog Scale (VAS) scores between resin-based and bioceramic root canal sealers at intervals of 6 hours, 12 hours, 24 hours, and 48 hours after treatment.

Conclusion

The findings of this systematic review and meta-analysis suggest that after the utilization of bioceramic sealers during root canal therapy, the pain and discomfort levels were not significantly different from those experienced pain after the use of resin-based sealers.

An In Vitro Comparative Analysis of Physico-Mechanical Properties of Commercial and Experimental Bioactive Endodontic Sealers

This study aimed to evaluate the fracture resistance of root and sealer penetration after obturation using an epoxy resin sealer AH plus (AH+) and two different bioactive endodontic sealers, i.e., Totalfill BC Hiflow (TF BC), and experimental injectable bioactive glass (Exp.BG). A thermo-sensitive injectable sealer was prepared by using a non-ionic triblock copolymer and bioactive glass. The root canals of human extracted teeth were obturated with the respective sealers. The fracture resistance was analyzed at different time intervals, i.e., days 7, 30, and 90. The morphological and elemental analyses of the fractured roots were conducted with a scanning electron microscopy and a electron dispersive spectroscopy. Sealer penetration depth and the percentage of penetrated sealers into the dentinal tubules were assessed with the confocal laser scanning microscope. Statistical analysis was performed using a one-way ANOVA post hoc Tukey's test. The mean fracture force in AH+ was significantly higher on day 30 (664.08 ± 138.8 N) compared to day 7 (476.07 ± 173.2 N) and day 90 (493.38 ± 120.18 N). There was no statistically significant difference between the TF BC and Exp.BG at different time intervals. The maximum penetration was observed in the middle region compared to coronal and apical for the Exp.BG, followed by the TF BC and AH+ groups; however, a nonsignificant difference in penetration was found over time. It is concluded that the TF BC group showed overall better fracture resistance than AH+ at day 90. Exp.BG showed comparable sealer penetration to those of TF BC and better than those of AH+.

Does selective root canal retreatment preserve the tooth's fracture resistance? An ex-vivo study

OBJECTIVES

To assess the tooth's fracture resistance when submitted to a selective root canal retreatment compared to the conventional approach.

METHODS

33 intact permanent mandibular first molars were selected according to specific criteria. After teeth mounting, the primary root canal treatment was conducted and followed by thermo-mechanical aging procedures to mimic a few clinical conditions. The specimens were randomly divided into three groups (n = 11); a control group in which intact teeth were used and two experimental groups according to the retreatment approach: conventional non-surgical retreatment (Conventional-NSR), and selective non-surgical retreatment (Selective-NSR). Later, the teeth were submitted to a final thermo-mechanical aging procedure and tested regarding their fracture resistance (static fracture test). The maximum load to fracture was recorded as were the types of failure modes (repairable or non-repairable fracture). A proper statistical analysis was conducted, considering a significance level of 5%.

RESULTS

The Conventional-NSR group showed a mean failure load of 867.7 ± 108.9 N while the Selective-NSR group had 1106.8 ± 159.8 N (P = 0.012). Both retreatment groups showed significantly lower results when compared to the control group. Additionally, the Conventional-NSR group showed higher proportions of non-repairable fractures (54.5%) when compared to both the Selective-NSR (36.4%) and control (18.2%) groups.

CONCLUSIONS

Selective root canal retreatment preserved the tooth's fracture resistance compared to the conventional retreatment approach.

CLINICAL TRIAL NUMBER

Non-applicable. Conducting the current experiment was limited to obtaining approval from the local Research Ethics Committee at the Faculty of Dentistry, Minia University (Committee No. 105, Registration No. 902, Date: 26/3/2024).

Volumetric correlation of periapical lesion with Orstavik's periapical index: A retrospective cone-beam computed tomographic study

Aim

To assess the correlation among cone-beam computed tomographic periapical volume index (CBCTPAVI) and periapical lesion volume with Orstavik's periapical index (PAI).

Methodology

Seventy-six cone-beam computed tomographic (CBCT) and periapical radiographic images of single-rooted teeth presenting with apical periodontitis from 42 patients were obtained from a period of March 2023 to April 2024. Two observers evaluated the periapical radiographs and assigned PAI scores. CBCTPAVI was allocated based on the volume of the lesion, which was computed using ITK-SNAP software. Spearman's correlation coefficient was employed to evaluate the association between CBCTPAVI and lesion volume with PAI.

Results

A significant and moderate positive relationship between PAI and lesion volume (ρ = 0.553, P < 0.001) as well as between PAI and CBCTPAVI (ρ = 0.506; P < 0.001) was observed.

Conclusion

The risk of under/overestimation of results on two-dimensional periapical radiographs exists, despite a favorable connection with volumetric assessment of CBCT images.

A Fluorescence-based Method to Reaccess Root Canals in Endodontically Treated Teeth: A Micro-Computed Tomography Tridimensional Assessment

INTRODUCTION

The aim of this study was to evaluate the volume of dentin removal and the volume of remnants of restorative material after the removal of an esthetic restorative coronal set and cervical barrier in endodontically treated mandibular molars with the aid of different magnification methods using 3-dimensional (3D) micro-computed tomographic (micro-CT) morphometric analysis.

METHODS

A sample of 30 mandibular first molars (N = 30) was used. All teeth were endodontically treated, and the specimens were initially scanned using micro-CT imaging and reconstructed. The molars were filled by a single-cone technique, and immediately the material at the initial 2-mm cervical level was removed. Cervical barriers were confected using ionomer glass cement with fluorescein 0.1%, filling the 2 mm at the cervical level of the canals and an additional 2 mm as the base. The coronal restoration set was performed using esthetic resin composites. A simulated tooth aging process was performed with 20,000 thermocycling cycles. The sample was distributed into the following 3 groups (n = 10) for the removal of the restoration set and cervical barrier with diamond burs based on the magnification aid: no magnification aid (naked eye), operative microscope aid, and REVEAL device (Design for Vision Inc, Bohemia, NY) aid. After removal, the final 3D micro-CT scanning and reconstruction were conducted with the same parameters as the initial scanning, and superposition of the final and initial scanning was performed. Morphometric analysis was conducted using CTAn software (Bruker microCT, Kontich, Belgium) to assess the volume of remnant restorative material (mm³), the volume of dentin removal (mm³), and the direction and site of dentin removal. Data were analyzed using 1-Way analysis of variance (P < .05).

RESULTS

The REVEAL group showed better results regarding the volume of remnant material (3.17 ± 1.65) and the percentage of dentin removal (2.56 ± 1.34). The microscope group showed no statistical difference compared with the REVEAL group regarding dentin removal (3.30 ± 1.48) and was statistically similar to the naked eye group in the volume of remnant material (9.63 ± 4.33). The naked eye group showed the worst results for the volume of remnant material (7.60 ± 2.68) and the percentage of dentin removal (6.60 ± 3.70).

CONCLUSIONS

The use of fluorescence associated with magnification was the method that presented the best results, with lower percentages of dentin removal and smaller volumes of remaining restorative material. This is an innovative technology in endodontics that shows potential to overcome the challenge of reaccessing root canals in the context of endodontic retreatment.

Outcome of Nonsurgical Root Canal Treatment of Teeth With Large Apical Periodontitis Lesions: A Retrospective Study

INTRODUCTION

This study reported on the outcome of the nonsurgical root canal treatment/retreatment of teeth with large apical periodontitis lesions. The influence of some variables on the prognosis was also evaluated.

METHODS

The study included 199 teeth with large apical periodontitis lesions from 184 patients, treated/retreated by a single operator. Most teeth were managed in a single visit using NaOCl irrigation. Cases were followed up periodically from >1 to 8 years. Treatment/retreatment outcome was evaluated by clinical and radiographic/tomographic criteria and categorized as healed, healing, or diseased. For statistical analysis, data were dichotomized in such a way that healing cases were considered as success in a loose criterion or failure in a rigid one.

RESULTS

Clinical/radiographic analyses revealed that 67% of the initial treatment cases were classified as healed, 22.5% as healing, and 11% as diseased. Treatment success rates were 89% (loose) and 67% (rigid). Variables that influenced the treatment outcome included previous abscess and antibiotic use, very large lesions (≥10 mm), and a sinus tract. The median follow-up time for treatment was 31.5 months. As for retreatment cases, 47% were healed, 32% were healing, and 21% were diseased. Retreatment success rates were 79% (loose) and 47% (rigid), in a median follow-up of 32 months. Cases evaluated by cone-beam computed tomography had lower healed rates.

CONCLUSIONS

Findings demonstrate that high favorable outcome rates can be achieved by nonsurgical root canal treatment or retreatment of teeth with large apical periodontitis lesions.

Systemic Factors Affecting Prognosis and Outcome of Endodontic Therapy

The successful outcome of endodontic treatment is dependent on the immune response and the reparative potential of the individual. Alteration in the host immune response is a common characteristic shared by both apical periodontitis and systemic diseases. Although infection-induced periapical lesions occur in a localized environment, numerous epidemiologic studies in the last few decades have investigated the potential association between endodontic disease pathogenesis and systemic diseases. The goal of this review is to identify common systematic factors and discuss the effect they may or may not have on the prognosis and outcome of endodontic therapy.

Assessment of Periodontitis Risk Factors in Endodontically Treated Teeth: A Cross-Sectional Study

The aim of the study was to collect data about the prevalence and risk factors of apical periodontitis in a population of endodontically treated patients. The study group included 151 patients (52 males, 99 females; mean age 48.36 ± 15.708 yrs.) with 391 endodontically treated teeth (mean follow-up of 5.25 ± 1.759 yrs.). According to the initial tooth diagnosis, root-filled teeth were divided into Group A, root-filled teeth treated for pulpitis or for the purpose of prosthetic pulpectomies (vital pulp group), and Group B, root-filled teeth with non-vital pulp (necrotic pulp). Clinical and radiographic evaluation of the root and its periapical area were performed to establish the success/failure of endodontic therapy, the quality of the root canal fillings (length, density, taper), and coronal restoration. The presence of recurrent caries, periodontal pathology, or endo-periodontal lesions were also recorded. Univariate and multivariate analyses were used to determine the risk factors for apical periodontitis and calculate their odds ratios (ORs). For the root-filled vital pulp tooth group, the highest risks for apical periodontitis are associated with inadequate homogeneity (OR 30.938), periodontitis (OR 9.226), and over-filling (OR 8.800). For the root-filled non-vital pulp tooth group, the highest risks are associated with periodontitis (OR 4.235) and age over 60 yrs. (OR 4.875). For the necrotic pulp tooth group, multivariate analysis identified an age > 60 yrs., filled molars, intracanal posts, poor coronal restoration quality, under-filling, and periodontitis as significant combined risk factors. Inadequate root canal filling and periodontitis in both groups were risk factors associated with most cases of apical periodontitis. Other risk factors include age > 60 yrs., poor coronal restoration quality, and the presence of intracanal posts in root-filled teeth with necrotic pulp.

Current Endodontic Practices among Romanian Dental Practitioners: A Cross-Sectional Study

Root canal therapy (RCT) is usually performed in Romania by general dentists (GDPs) because they are more readily available and more reasonably priced than endodontists. Concerns have been raised about the quality of RCTs performed by GDPs, possibly due to insufficient equipment or knowledge; therefore, this study aims to investigate current endodontic practices in Romania. Materials and Methods: A cross-sectional study was conducted via a questionnaire distributed to 400 randomly selected Romanian dentists, with 285 fully validated completed responses (71.25% response rate). Respondents were grouped by speciality, and statistical analysis, including cross-tabulation and the χ2 (chi-square) test, was used, with a significance level set at p ≤ 0.05 for all tests. Results: Significant differences were found in the use of magnification, rubber dam, sodium hypochlorite concentration, and bioceramics (p < 0.001). No significant differences were observed in preferences for measuring working length (p = 0.166) or rotary instrument motion (p = 0.289). Approximately 6% of the respondents used laser technology with no significant difference across specialities (p = 0.571). Additionally, 77.9% preferred using sodium hypochlorite, with no significant difference between groups (p = 0.006) regarding concentration. Conclusions: Most participants, including GDPs, use modern equipment and techniques during RCT, indicating their awareness and competence in current endodontic practices.

Interventions in root-filled teeth identified in general dental practice: A 6-year longitudinal observational study

AIM

To investigate what happens to cross-sectionally identified root-filled teeth over a 6-year period, regardless of the time that elapsed since primary root canal treatment, in a cohort of adult patients regularly attending a Public Dental Service. A secondary aim was to investigate how the cumulative events affecting root-filled teeth over the same time were associated with variables obtained from a baseline examination.

METHODOLOGY

Adult patients with ≥1 previously root-filled tooth and regularly attending the Public Dental Service in Örebro County were enrolled for study participation in 2015. General dental practitioners examined all identified root-filled teeth in this cohort at baseline using a standardized protocol and were also responsible for further decision-making and treatments. After six years, information on events of the root-filled teeth was collected from dental records. The highest rating (most invasive treatment) on a 5-point ordinal scale was used in the analyses. Regression analyses with stepwise selection were performed for associations between patient- and tooth-related factors and events.

RESULTS

A total of 445 patients with 1007 root-filled teeth were followed the entire observation time. Twenty (2.0%) of the root-filled teeth had endodontic retreatment and 150 (14.9%) were extracted over six years. Among teeth with periapical radiolucency or pain, the majority did not undergo retreatment or extraction; however, the multivariate analysis demonstrated that retreatment or extraction was associated with baseline recordings of teeth with periapical radiolucency (p < .0001), tenderness to percussion (p < .0001), and poor coronal restoration (p < .0001).

CONCLUSIONS

This study corroborates the notion that in general dentistry, root-filled teeth with radiological signs of apical disease often remain untreated over time. Furthermore, it also reveals that root-filled teeth presenting with mild pain do not necessarily receive any intervention. However, teeth with baseline signs of apical periodontitis, pain, or inadequate coronal restoration were more likely to have received intervention during the six-year period.

Expert consensus on the diagnosis and therapy of endo-periodontal lesions

Endo-periodontal lesions (EPLs) involve both the periodontium and pulp tissue and have complicated etiologies and pathogenic mechanisms, including unique anatomical and microbiological characteristics and multiple contributing factors. This etiological complexity leads to difficulties in determining patient prognosis, posing great challenges in clinical practice. Furthermore, EPL-affected teeth require multidisciplinary therapy, including periodontal therapy, endodontic therapy and others, but there is still much debate about the appropriate timing of periodontal therapy and root canal therapy. By compiling the most recent findings on the etiology, pathogenesis, clinical characteristics, diagnosis, therapy, and prognosis of EPL-affected teeth, this consensus sought to support clinicians in making the best possible treatment decisions based on both biological and clinical evidence.

Evaluation of Minimally Invasive Preparation of Curved Mesial Canals of Mandibular Molars - An In Vitro Study

INTRODUCTION

Curved mesial roots can be challenging for different stages of endodontic treatment. Preparation aims to enlarge, clean, and shape the root canal system, and hundreds of systems are available to carry it out. Aiming to maintain pericervical dentin, minimally invasive preparation was proposed, and with it, instruments with lower tapers emerged. This study aimed to evaluate the increase in canal volume, the centering ability of the instruments, and root canal transportation of two different rotary systems with lower tapers.

METHODS

Eighteen curved mesial roots of extracted mandibular molars were scanned by micro-CT at 3 moments: initial and after the 2 stages of endodontic preparation. The canals were prepared using TruNatomy (TN) and ProDesign Logic 2 (PDL2) instruments up to sizes 25.04 and 26.04, respectively, and after 36.03 and 35.05, respectively. The data were analyzed using parametric and nonparametric tests with a significance level of 5%.

RESULTS

TN and PDL2 systems showed no difference regarding the increase in the volume of the canals with the first instruments, but after preparation with a diameter size of 35 or 36, there was a difference (P < .01) between the systems in the cervical and middle thirds.

CONCLUSION

Both systems shaped the mesial canals of mandibular molars while keeping low transportation and good centering ability in enlargements up to diameter size 35 or 36 with tapers of 3 or 5%.

An Online Survey on the Current Trends in Root Canal Treatment

Root canal treatment in several regions of Saudi Arabia is commonly administered by general dental practitioners (GDPs) rather than specialized endodontists. The study aimed to compare the endodontic practices and preferences of general dental practitioners with those of endodontists and restorative specialists. A structured questionnaire including 23 questions focussing on fundamental principles and techniques used in contemporary root canal treatment was distributed online to 600 dentists who perform root canal treatments and are registered with the Saudi Dental Society (SDS). Data were gathered for basic demographic and professional details, practices, and preferences in endodontic materials and methods. The collected data were analyzed using SPSS version 21 (Armonk, NY: IBM Corp.). For selected variables, frequency distributions and 95% confidence interval for sample proportions were measured. Associations between categorical variables were examined using cross-tabulation, with statistical significance assessed by the chi-square test of homogeneity or Fisher's exact test when necessary. The survey, with a 59% response rate primarily from participants aged 24-34 years (94.1%) with one to five years of experience (90.4%), revealed that most GDPs referred root canal treatment (RCT) cases due to lack of skills (82.8%), performed restorability assessments (90.9%), preferred Cavit for tooth buildup (87%), consistently used rubber dam isolation (91.5%), treated mainly anterior teeth (91.2%) without magnification (87.9%), used electronic apex locators for working length determination (63.3%), favored stainless steel K files and single cone obturation, while specialists exhibited wider clinical experience, more frequent use of advanced techniques, and higher usage of intracanal medicaments (91.7%) and ethylenediaminetetraacetic acid (EDTA) as irrigant (70.8%). The study provides valuable insights into the endodontic preferences and practices of dentists in the Kingdom of Saudi Arabia, revealing significant differences between general dental practitioners and specialists. The findings highlight critical areas for improvement, such as the need for enhanced training in endodontic skills and better access to modern materials and equipment.

A Comparative Ex Vivo Study on Apex Locator Precision in Mature Teeth and Immature Teeth With Divergent Canals

AIM

This study investigates the accuracy of an apex locator in mature and immature teeth with divergent root canals ex vivo.

MATERIALS AND METHODS

Fifty extracted premolar teeth were utilized for the study, with 25 mature teeth (Nolla stage 9 or 10) and 25 immature teeth (Nolla stages ≤ 8). The discrepancies between the actual length (AL) and the electronic length (EL), measured using a Bingo 1020 apex locator, were compared and analyzed. Statistical analysis included Pearson's correlation analysis, a T-test for independent samples, and multiple linear regression. Statistical significance was set at p < 0.05.

RESULTS

The difference between AL and EL in immature teeth was significantly higher than in mature premolar teeth. Nonetheless, patient gender or jaw type (upper/lower) did not affect the accuracy of electronic apex locator (EAL) measurements.

CONCLUSION

EAL readings are less accurate in immature teeth than in mature teeth. Supplementary measures, such as radiographic length determination and wet-dry paper point tests, are required to confirm the working length for improved treatment outcomes and patient compliance.