The aim of this study was to assess the effectiveness of filling removal material from the apical third of curved mesial root canals of mandibular molars. Reciprocating instrumentation followed by additional rotary instrumentation with instruments made of alloys with different heat treatments was evaluated. Thirty-six mesial roots of mandibular molars were divided into two groups: Group Class IV consisted of 16 roots with two independent canals, and Group Class II consisted of 20 roots with two canals that merged into one at their apical level. Each of these two groups were further divided into two subgroups, according to the additional rotary instrument used after the reciprocating instrumentation: Group RH and Group RM for Hyflex and Mtwo, respectively. After each procedural step, the roots were scanned by micro-tomography. After each step of filling removal, the Wilcoxon matched pair test and the Mann-Whitney test were used for the evaluation between groups. The significance level adopted was 5%. Significant differences were observed between groups with different Class II and Class IV anatomies, regarding filling removal after Reciproc (P<0.05). After the use of an additional rotary instrumentation, no differences were observed between the two groups (P>0.05). In the apical third of mesial roots of mandibular molars with Class II anatomy, an additional rotary instrumentation was shown to be necessary for improving the removal of filling material after using the single-file reciprocating instrumentation technique.

Foraminal Enlargement (FE) is a cleaning performed in the apical-most region of the tooth, in order to optimize root disinfection. This systematic review evaluated the influence of FE during root canal treatment on bacterial reduction and repair of the periapical lesion. Searches in PubMed/MEDLINE, Scopus, Cochrane Library, Web of Science, Embase, Scielo, Lilacs and OpenGrey were performed until January-2024. Ex vivo and in vivo studies evaluating the effects of FE in the bacterial reduction and repair of the periapical lesion were included, respectively, followed by risk of bias assessment (modified version of Joanna Briggs Institute's for ex vivo studies and Systematic Review Centre for Laboratory animal Experimentation's risk of bias tools for in vivo studies). The meta-analysis was not feasible and a qualitative summary for each outcome was provided. Of 950 studies, 2 in vivo studies were eligible, using animal models with infected teeth. Of these two, periapical repair was evaluated with hematoxylin-eosin stain, and FE improved periapical healing. Regarding ex vivo studies, 3 were eligible, using extracted human teeth. The inoculations in ex vivo models were performed with Enterococcus (E.) faecalis, and FE reduced E. faecalis in the ex vivo models. Foraminal enlargement seems to increase bacterial reduction within the root canal, and provide major periapical tissue repair on the histological analysis in animal studies. However, caution is necessary when translating these results to the clinical environment.

Calcium silicate-based sealers are an alternative to be used into root canal, mainly to their biological properties. However, some biological parameters need to be determined in an in vivo animal research model. So, the aim of the present study was to evaluate in vivo the tissue biocompatibility of a calcium silicate-based sealer (EndoSequence BC Sealer) and an epoxy resin-based sealer (AH-Plus). Polyethylene tubes were filled with freshly mixed sealers and implanted in connective subcutaneous tissue of 25 rats (5/euthanasia day) (Rattus norvegicus albinus). Empty tubes were used as controls and no tubes as sham. Histopathological (hematoxylin eosin) and histochemical (Picrosirius red) examinations were conducted at 3, 7, 15, 30 and 60 days (five rats/day) after the implantation procedure (n=5/group). The type/intensity of inflammation and collagenesis was analyzed statistically with Friedman or Kruskal-Wallis/Dunn tests (P<0.05). The profile of inflammation induced by AH-Plus (Median=2, Range=2-3) was significantly greater than that by Endosequence BC Sealer (Median=1, Range=1-1) during the 15-day experimentation period (P=0.018). After 30 days, both materials produced similar tissue reaction (P>0.05). AH-Plus and Endosequence BC Sealer (Median=2, Range=1-2) induced a high level of fibrosis after 60-day than control (Median=1, Range=1-1) and sham (Median=0, Range=0-0) groups (P<0.001) of fibrosis based in type I collagen increase (P=0.025 and P=0.021, respectively). Tissue necrosis was not observed and the bioceramic sealer showed significant signs of endocytosed (Median=1, Range=1-1) material after 7 days than other groups (Median=0, Range=0-0) (P<0.05). The calcium silicate-based sealer induced tissue repair faster than the epoxy resin-based sealer tested. However, both materials showed adequate biocompatibility and tolerance by subcutaneous tissues, with few differences in inflammatory profiles, formation of granulation tissue, and collagenesis. It may be concluded that calcium silicate-based sealer (EndoSequence BC Sealer) and an epoxy resin-based sealer (AH-Plus) presented suitable biocompatibility.

In this study, the cleaning ability of a stainless-steel rotary instrument called Gentlefile, was compared with three nickel-titanium rotary instruments. In this in vitro study, forty mandibular single-rooted premolars were randomly assorted into four groups: Gentlefile, ProTper Universal, RaCe files, and XP-Endo Finisher/ProTaper Universal system (n=10). Final instrumentation was done using the aforementioned files with 5.25% sodium hypochlorite and normal saline for root canal irrigation. Debris and smear layers were observed by the scanning electron microscope on the canal walls in the coronal, middle, and apical third of the root level, through a 4-point scoring system. The chi-square test and Kruskal-Wallis were used for data analysis. The Gentlefile demonstrated a promising outcome in smear layer clearance and debris removal compared with the other three rotary systems (P<0.05), specifically at the apical third of the root canal. Based on chi-square test results, there was a significant relationship between root canal cleaning (three levels of cleanliness) in ProTaper Universal (P=0.004) and Gentlefile (P=0.04) groups. Neither of the investigated systems achieved complete cleanliness. The Gentlefile rotary system can be capable of cleaning the apical third of root canals more than the other three groups including Protaper Universal, RaCe, and XP-Endo Finisher.

Endodontic therapy has been regarded as a safe treatment option with highly promising results in preserving natural teeth. Numerous factors may influence the longevity of endodontically treated teeth (ETT), thus altering their success/survival rate. This study aimed to determine the survival and success rates of endodontically treated premolars and molars with different complex restorative/prosthodontic treatments. A total of 190 patients with an ETT were included, who had received final coronal restoration up to 14 days after the temporary one and at least one year prior to the enrollment. The investigator evaluated the quality of endodontic filling, coronal restoration, mobility, and proximal contacts. Data were analyzed with multiple binary logistic regression and the Chi-Square test. The average duration of follow-up was 28.6±11.9 months. Overall, 89.4% (170/190) of the teeth survived. The overall success rate for the investigated teeth was 70.5% (134/190). Success rates of 100% for crown, 95.7% for post and core crown (PCC), and 94.7% for amalgam build-up with post were achieved. However, the success rates were 75%, 52.5%, and 50% for amalgam build-up, composite build-up, and PCC with crown lengthening, respectively. The Chi-square test revealed that there was a significant difference between the different restorations in terms of success (P<0.001). Multiple binary logistic regression models revealed that coronal leakage (P=0.048), obturation void (P=0.037), obturation length (P=0.020), mobility (P=0.002), type of the restoration (P<0.001), and proximal contact (P<0.001) were significant predictors for success. However, apical lucency, root length, marginal caries, tooth type, and post did not appear to be significant indicators of success (P>0.05). ETT with minimal mobility, exhibiting underfilled obturations without visible voids, and having received crown/PCC/amalgam build-up with a post, along with the presence of both proximal contacts, tend to exhibit a significantly high success rate.

Currently no standard, universally accepted, and clinically useful classification of pulp, root canal and peri-radicular conditions is used within the dental profession. Most published classifications are either too simple and miss many of the conditions reported to occur within the pulp, root canal and peri-radicular tissues, or they are too complex for use in clinical settings. Furthermore, many classifications have used inappropriate terminology that has either not been defined or has been poorly defined. The lack of standardisation leads to confusion amongst practitioners and potential uncertainty regarding treatment. It also limits the ability to communicate effectively, to teach appropriately, and to compare data and research findings throughout the world. When developing a classification of tissue conditions or diseases, it is essential that the classification is developed appropriately and meets the recommended criteria for effective clinical, educational and research use. It is also extremely important that correct and well-defined terminology is used since "words do matter". Popular terminology based on symptoms should be avoided as these have been proven to lead to inappropriate treatment decisions. This review discusses how classifications should be developed for pulp, root canal and peri-radicular conditions. It also discusses the deficiencies of some popular classifications and outlines the classifications that truly address the recommended criteria and reflect the physiological and pathological changes in the pulp, root canal and peri-radicular tissues. Hence, it is recommended that these latter classifications be adopted as the internationally-accepted classifications for future clinical use, as well as for educational, research and communication purposes.

Rotary systems have made significant advances to improve their root canal preparation efficacy. These instruments can properly preserve the root canal anatomy and morphology. The present in vitro study aimed to compare canal transportation and centering ability of RaCe and Af f-one systems using cone-beam computed tomography. Thirty-six mandibular molars were included. The samples were randomly assigned to two groups (n=18): group 1, RaCe, and group 2, Af f-one. Canal preparation was conducted using the respective files according to the manufacturers' instructions. The cone-beam computed tomographic scanning of the samples was performed before and after preparation. The data were analyzed by using two-way ANOVA. In both the RaCe and Af f-one rotary systems, canal centrality and transportation were similar at coronal, middle, and apical cross-sections. In addition, canal transportation and centrality were identical in the RaCe and Af f-one rotary files (P<0.05). The two studied rotary systems did not exhibit significant differences in root canal transportation and preservation of root canal centrality in the apical, middle, and coronal thirds.

This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Forty mandibular premolars with oval canals were divided into four groups based on the sealer used (AH-Plus or Bio-C Sealer) and the cleaning technique employed (PUI or XPR). To ensure uniformity of canal volume among groups, initial micro-CT scans were conducted. The canals were instrumented, filled, and then re-instrumented before undergoing either PUI or XPR cleaning techniques. Residual filling material volumes were assessed through micro-CT scans, and statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests. Following instrumentation, there was no significant difference in residual filling material volumes between AH-Plus and Bio-C Sealer groups (1.35 mm3and 1.02 mm3, respectively; P>0.05). However, after supplementary cleaning techniques, XPR-cleaned specimens exhibited significantly less residual material compared to PUI-cleaned specimens (0.01 mm3 and 0.29 mm3 for Bio-C Sealer, and 0.07 mm3 and. 0.30 mm3for AH-Plus, P<0.05). The XPR system was found to be more effective than PUI in removing residual filling material from Bio-C Sealer-filled root canals. This highlights its potential as a useful supplementary cleaning technique in endodontic retreatment procedures.

Invasive cervical root resorption (ICRR) is a dental pathology, marked by unexpected destruction originating in the cervical region of the tooth. This comprehensive literature review provides a holistic view into the pathogenesis, clinical manifestation, and precise management of ICRR, aiming to guide endodontists and enhance patient care and treatment outcomes. The review delves into the potential etiology of ICRR, covering contributing factors such as trauma, orthodontic treatment, and other pertinent conditions. It outlines the clinical and radiographic indicators, underscoring the crucial role of early detection and precise diagnosis in effectively managing and halting ICRR progression. The exploration of treatment approaches is thorough, ranging from non-surgical methods like vital pulp therapy or root canal treatment to surgical interventions. This review accentuates the essential role of interdisciplinary collaboration among diverse dental specialties in enhancing ICRR management. It highlights the importance of a consolidated strategy in enhancing treatment outcomes and preserving tooth structure and function. Moreover, it investigates prevention methods, risk evaluation, and identifies prospective research pathways to address the existing knowledge gaps.

This non-randomized clinical trial investigated the outcomes of full pulpotomy in adult molars with irreversible pulpitis, comparing those with calcified and non-calcified pulp chambers over 6 and 12 months. A total of 101 adult permanent molars with irreversible pulpitis, in individuals over 12 years old, were categorized based on pulp chamber calcification observed in radiographic images by two endodontists. Subsequently, full pulpotomy procedures were performed, achieving hemostasis, and applying a 2 mm layer of calcium-enriched mixture (CEM) cement as a pulp covering agent. After 48 hours, the setting of the CEM cement was verified, followed by the application of a layer of resin-modified glass-ionomer. The tooth was then restored using amalgam. Clinical and radiographic evaluations were conducted at 6-month and 1-year follow-ups by blinded endodontists. Success rates were compared using Fisher's exact test and logistic regression tests with a significance level of 0.05. Among the 97 patients with 6-month and 1-year follow-ups, all achieved clinical success. Radiographic success rates were 99% at 6 months and 96.9% at 1 year, regardless of pulp calcification. In the 6-month follow-up, success rates were 98.07% for non-calcified pulp chambers and 100% for calcified pulp chambers. At the 1-year follow-up, success rates were 96.1% and 97.8%, respectively. Statistical analysis showed no significant difference in radiographic success rate between the two groups at both follow-ups (P>0.05). Full pulpotomy using CEM cement is a successful treatment for adult permanent teeth with calcified and non-calcified pulp chambers presenting signs and symptoms of irreversible pulpitis up to a 1-year follow-up. This study provides compelling evidence that vital pulp therapy can be effectively employed in the pulpotomy of calcified teeth, at least in the short term.