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Recent decades clearly demonstrate the growing use of nanomaterials in medical practice, and their effectiveness is systematically confirmed by the consequent scientific research. An example of the use of nanomaterials in dentistry is endodontic treatment, which, due to its specificity, is one of the most demanding procedures, fraught with numerous challenges, such as difficulties in reaching tooth roots and ineffective cleaning or insufficient sealing of root canals, which may lead to re-infection or damage to adjacent structures. The use of nanomaterials has a positive impact on solving these problems, and the combination of biomaterials with nanometric technology makes endodontic treatment more effective, precise and comfortable for patients, which contributes to improving the quality of dental care. Currently, nanomaterials with a high biocompatibility can be used in endodontics as components of irrigation solutions, for rinsing root canals and as drug carriers for intracanal use. Nanomaterials are also components of sealants filling root canals. However, the latest research shows that reducing the size of materials to the “nano” scale significantly affects their basic physicochemical properties, which leads to increased reactivity and the ability to interact at the molecular level. These unique physicochemical properties, which have contributed to the use of nanomaterials in numerous medical-related solutions, raise concerns and provoke discussions about the safety of their use in direct contact with tissues.

The critically important preoperative and intraoperative factors that affect the success of endodontic microsurgery (EMS) in Japanese patients are not defined. We conducted a retrospective study that analyzed treatment outcomes for 46 teeth in 46 Japanese patients. Treatment was provided between March 2013 and March 2015. All patients were evaluated after one year, the shortest time period over which treatment outcomes after apicoectomy could be evaluated and in which there were complete records for the recruited patient population. Healing was assessed on the basis of clinical symptoms and radiographs. With the use of a binary logistic regression model to quantify success, we estimated the effects of patient age, sex, dental arch, lesion size, lesion type, preoperative root canal treatment, the presence or absence of a post core, and the presence or absence of an isthmus on the surgically prepared dentine surface. The overall success for EMS was 93.5% after one year; failures comprised 6.5%. Successful outcomes were higher (p = 0.04) for maxillary teeth than for mandibular teeth. Success was higher (p = 0.019) for patients who received root canal instrumentation prior to EMS. Age, sex, lesion size, lesion type, the presence or absence of a post core, and the presence or absence of a root canal isthmus had no effect (p > 0.2) on success. We conclude that the percentage of successful outcomes after EMS treatment for Japanese patients presenting with periapical periodontitis is very high after one year and that success is influenced strongly by the dental arch and preoperative root canal instrumentation.

The introduction of nickel–titanium rotary instruments revolutionized shaping procedures as they were able to produce a well-tapered preparation while reducing operator fatigue. The major drawback of rotary instruments was the high risk of fracture due to bending and torsional stress. Thus, the creation of a glide path has been advocated and recommended by most rotary instrument manufacturers. The aim of the present review is to summarize existing knowledge on glide path preparation and identify areas where further research is needed. The primary goal is to provide a comprehensive overview of the techniques and instruments used in glide path preparation, highlighting their advantages and limitations. The secondary goal is to explore the effect of glide path creation on the overall success of endodontic treatment, particularly in terms of reducing procedural errors and improving treatment outcomes. An online search on PubMed, ScienceDirect, UCLA, and Scopus databases was conducted, and 116 articles were identified. Eligible articles were divided into nine categories based on what they researched and compared. The categories included centering ability and/or root canal transportation, cyclic fatigue resistance, glide path and shaping time, tortional stress resistance, apical extrusion of debris and/or bacteria, defects in dentine walls, file separation, postoperative pain assessment, and scouting ability and performance. Establishing a glide path reduces root canal transportation, especially with rotary methods. Reciprocating and heat-treated files offer higher fatigue resistance and shorter preparation time. Instruments with shorter pitch lengths have greater torsional strength. Preparation and coronal preflaring reduce apical debris and bacteria. Glide paths do not affect dentine microcracks, file separation, or defects but reduce immediate postoperative pain and improve cutting ability. Randomized trials are needed to assess their impact on treatment outcomes.

According to contemporary dental standards, the primary goal of endodontic therapy is the chemo-mechanical cleaning of the complex root canal system. Watering root canals with approved solutions and activating them are essential parts of this operation. This review outlines various irrigant activation methods for root canal therapy. Specifically, a comparison among the methods of manual dynamic activation, sonics (subsonic, sonic, and ultrasonic), internal heating, and lasers, was conducted. The results in this work were gathered using Scopus, Web of Science, Google Scholar, and PubMed databases by searching the following keywords: sodium hypochlorite, cleaning, activation, and irrigation methods. The present work concluded that the use of irrigant activation has a greater benefit than its absence. Regardless, it is impossible to point to a single effective activation method.

The primary aim of this literature review is to delineate the key inflammatory cytokines involved in the pathophysiology of pulp inflammation. By elucidating the roles of these cytokines, a deeper comprehension of the distinct stages of inflamed pulp can be attained, thereby facilitating more accurate diagnostic strategies in endodontics. The PRISMA statement and Cochrane handbook were used for the search strategy. The keywords were created based on the review question using the PICO framework. The relevant studies were meticulously assessed according to predefined inclusion and exclusion criteria for this systematic review. A rigorous quality checklist was implemented to evaluate each included study, ensuring scrutiny for both quality and risk-of-bias assessments. The initial pilot search conducted on PubMed, Scopus, Cochrane, and WoS databases yielded 9 pertinent articles. Within these articles, multiple cytokines were identified and discussed as potential candidates for use in endodontic diagnosis, notably including IL-8, IL-6, TNF-α, and IL-2. These cytokines have been highlighted due to their significant roles in the inflammatory processes associated with pulp pathology. The identification of specific inflammatory cytokines holds promise for enhancing endodontic diagnostic procedures and exploring diverse treatment modalities. However, the current body of research in this area remains limited. Further comprehensive studies are warranted to fully elucidate the potential of cytokines in refining diagnostic techniques in endodontics.

The resistance of nickel–titanium endodontic instruments against cyclic fatigue failure remains a significant concern in clinical settings. This study aimed to assess the cyclic fatigue strength of five nickel–titanium rotary systems, while correlating the results with the instruments’ geometric and metallurgical characteristics. A total of 250 new instruments (sizes S1/A1, S2/A2, F1/B1, F2/B2, F3/B3) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-Files systems underwent mechanical testing. Prior to experimental procedures, all instruments were meticulously inspected to identify irregularities that could affect the investigation. Using a stereomicroscope, design characteristics such as the number of spirals, length, spirals per millimeter, and average helical angle of the active blade were determined. The surface finishing characteristics of the instruments were examined using a scanning electron microscope. Differential scanning calorimetry was employed to establish the instruments’ phase transformation temperatures, while energy-dispersive X-ray spectroscopy was utilized to analyze the elemental composition of the alloy. The instruments were subjected to cyclic fatigue testing within a stainless steel non-tapered artificial canal featuring a 6 mm radius and 86 degrees of curvature. Appropriate statistical tests were applied to compare groups, considering a significance level of 0.05. The assessed design characteristics varied depending on the instrument type. The least irregular surface finishing was observed in U-Files and Premium Taper Gold files, while the most irregular surface was noted in Go-Taper Flex. All instruments exhibited near-equiatomic proportions of nickel and titanium elements, whereas ProTaper Universal and U-Files instruments demonstrated lower phase transformation temperatures compared to their counterparts. Larger-sized instruments, as well as ProTaper Universal and U-Files, tended to display lower cyclic fatigue strength results. Overall, the design, metallurgical, and cyclic fatigue outcomes varied among instruments and systems. Understanding these outcomes may assist clinicians in making more informed decisions regarding instrument selection.

The fracture of nickel–titanium (Ni-Ti) instruments during root canal instrumentation leads to compromised outcomes in endodontic treatments. Despite the significant impact of instrument facture during a root canal treatment, there is still no universally accepted method to address this complication. Several previous studies have shown the ability of a Neodymium: Yttrium–Aluminum–Perovskite (Nd: YAP) laser to cut endodontic files. This study aims to determine safe irradiation conditions for a clinical procedure involving the use of a Neodymium: Yttrium–Aluminum–Perovskite (Nd: YAP) laser for removing fractured nickel–titanium files in root canals. A total of 54 extracted permanent human teeth (n = 54) were used. This study involved nine distinct groups, each employing different irradiation conditions. Groups 1 s, 3 s, 5 s, 10 s, and 15 s simply consist of irradiation for 1, 3, 5, 10, and 15 s, respectively. After identifying the longest and safest duration time, four additional groups were proposed (labeled A, B, C, and D). Group A was composed of three series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT). Group B consisted of three series of irradiations of 5 s each separated by a rest time of 60 s (L5s + 60 s RT). Group C consisted of two series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT), and group D consisted of two series of irradiations of 5 s each separated by a rest time of 5 s (L5s + 5 s RT). In all groups, during the rest time, continuous irrigation with 2.5 mL of sodium hypochlorite (3% NaOCl) was carried out. The variation in temperature during irradiation was registered with a thermocouple during irradiation with different protocols. The mean and standard deviation of the temperature increase was noted. The calculation of the temperature was made as the Δ of the highest recorded temperature at the root surface minus (−) that recorded at baseline (37°). Additionally, scanning electron microscopy (SEM) was used after irradiation in all groups in order to assess the morphological changes in the root dentinal walls. The Nd: YAP laser irradiation parameters were a power of 3W, an energy of 300 mJ per pulse, a fiber diameter of 200 µm, a pulsed mode of irradiation with a frequency of 10 Hz, a pulse duration of 150 µs, and an energy density of 955.41 J/cm2. Our results show that the safest protocol for bypassing and/or removing broken instruments involves three series of irradiation of 5 s each with a rest time of 30 s between each series. Furthermore, our results suggest that continuous irradiation for 10 s or more may be harmful for periodontal tissue.

Autotransplantation is a successful technique to replace compromised teeth. This study presents a computer-guided surgical approach for preparing the receiving socket for a mature mandibular third molar donor tooth with a wait-and-see approach instead of prophylactic endodontic treatment. A 42-year-old woman developed root resorption of tooth 3.7. Extraction of 3.7 and autotransplantation of 3.8 was planned, following a 6-week orthodontic phase for periodontal ligament activation and teeth mobilization. Due to the different root morphology between the compromised and donor teeth and the high mandibular bone density, the receiving socket preparation was performed using guided surgery templates. Two surgical splints were designed with a surgical planning software. Tooth 3.7 was extracted, the recipient site was guided-milled, and tooth 3.8 was transplanted into the new socket in approximately one second of extra-alveolar time. The rapidity of the extra-alveolar time facilitated complete healing without resorting to root canal treatment. Five-year radiological control does not show any periapical lesion or root resorption. The surgical procedure for tooth autotransplantation is fundamental: it must be as atraumatic as possible to preserve the periodontal ligament of the tooth and the receiving socket, and the dentist must minimize the extra-alveolar time. Guided surgery is a reliable solution to combine all these aspects.

The need for controlling bacteria and pain during root canal therapy is undeniable. This clinical trial aimed to assess whether there is a difference in colony-forming unit (CFU) reduction after instrumentation and post-endodontic pain after root canal treatment (RCT) using a traditional endodontic cavity (TEC) versus a conservative endodontic cavity (CEC). This clinical study was conducted on 89 patients designated for a single-visit RCT. Patients were allocated randomly (TEC n = 45 and CEC n = 44). The access opening was gained accordingly in each group by a single operator. A pre-instrumentation sample of root canal dentin was collected using an endodontic file; the second sample was collected similarly, right after shaping and cleaning the root canal. The CFU was calculated based on the samples collected. The pain level was recorded preoperatively and at 1, 7, and 21 days postoperatively utilizing a visual analog scale (VAS). There were no statistically significant differences in the CFU reduction between the TEC and CEC groups (p > 0.05). Additionally, there were no statistically significant differences found in postoperative pain levels between the TEC and CEC at 1, 7, and 21 days (p > 0.05). Despite the limitations of this study, both the CEC and TEC demonstrate a decrease in bacteria within the root canals and alleviate postoperative pain with no difference between them.

Concerns have been raised about the usage of sodium hypochlorite (NaOCl) in endodontics following its toxic effects. Effective ecoproduce (EEP), an organic solution produced through the fermentation of fruit peels, exhibits antibacterial and antibiofilm action, suggesting its potential as an endodontic irrigant. However, studies on its cytotoxicity are limited. This in vitro study aimed to evaluate the cytotoxic effects of EEP at different concentrations and fermentation periods against the MC3T3-E1 cell. EEP derived from orange and pineapple peel waste and fermented for 3 and 6 months was prepared from 100% to 0.78% concentration. Briefly, 2.5% NaOCl was used as the comparison group. Cell viability was analysed using Alamar Blue and Live and Dead Cell assay. A transmission electron microscope (TEM) was used to evaluate ultrastructural changes to the cells. Data analysis was performed using a two-way mixed Analysis of Variance (ANOVA). EEP exhibited concentration-dependent cytotoxicity regardless of the fermentation period (p > 0.05). A concentration below 6.25% was non-cytotoxic and comparable to the negative control (p > 0.05). Live and Dead Cell assay and TEM analysis complement the findings. The mean cell viability of EEP at all concentrations for both fermentation periods was significantly higher than that of 2.5% NaOCl (p < 0.05). Conclusively, 6.25% EEP fermented for 3 and 6 months are non-cytotoxic and can serve as an alternative endodontic irrigants.

A methodology for the structural assessment of Nickel-Titanium (Ni-Ti) endodontic files and a novel approach to predict their fatigue behavior using finite element method (FEM) were proposed. ProTaper-Universal F1 and F2 endodontic files were selected due to availability of extensive test data needed for the validation of the methodology. Bending and torsional loadings were analyzed since these provide essential data for the structural integrity assessment for the endodontic files. High-definition FEM models and their computationally efficient idealized versions were developed. The results for the bending and torsional stiffness of the F1 endodontic file agreed with the literature data validating the proposed methodology. Hysteresis energy density was shown to give promising results as a predictor of low cycle fatigue failure. The predictions with the idealized models matched those of the high-definition models, justifying the proposed idealizations. The validated models demonstrated that F2 has 60% higher bending and torsion resistance and 7% higher hysteresis energy density per cycle with respect to F1, leading to the conclusion that F1 has a lower structural stiffness but a longer fatigue life as compared to F2. In summary, the developed methodology allows for the structural and durability evaluation of various design parameters for Ni-Ti endodontic files.

The aim of the study was a quantitative analysis of p-chloroaniline (PCA) formation during 2% CHX activation with US and MDI methods in a root canal-like environment with the HPLC-DAD method and, thus, a safety assessment of US and MDI agitation of CHX in endodontic treatment. Two percent CHX was activated with the US method using ISO 30 and 35 K-file, and the MDI method using ISO 30.06 and 35.06 GP cones for 15, 30, 60, and 90 s. PCA concentration was assessed with the HPLC-DAD method. PCA concentration was also assessed for 2% CHX after 0, 3, 18, and 21 days of storage in ambient conditions. PCA was detected in all samples in all methods of activation. The concentration of PCA was dependent on time of activation in US ISO 30 and ISO 35 group (p < 0.05). In the MDI ISO 30.06 and ISO 35.06 groups, a similar trend was observed but without statistical significance (p > 0.05). PCA was detected in shelf-stored 2% CHX and the concentration was related to the time of storage. PCA is released after CHX activation with US and MDI, but mean concentrations are not higher than those observed from self-degradation of shelf-stored 2% CHX.

Boron-doped diamond (BDD) electrodes have been advocated as a potential treatment alternative to the established methods for root canal disinfection. As healing of periapical tissue is important in this context, the associated risk of host tissue damage was to be evaluated. Following in vitro cell culture experiments (HeLa cells), root canal treatment was performed in an animal trial comparing BDD electrode application and the currently used rinsing media with respect to cell viability and host tissue damage. Statistical analyses comparing the size of radiolucency were based on Kruskal-Wallis and Nemenyi’s All Pairs tests (α = 0.05). The direct application of BDD electrodes had a time-dependent effect on cell viability comparable to H2O2, NaOCl, and CHX application. In contrast to the chemical treatment, the effect of BDD electrodes was transient. Conventionally treated teeth and teeth additionally treated with BDD electrodes did not significantly differ from each other with respect to the size of the periapical radiolucency as observed radiographically (vertical p = 0.998 and horizontal p = 0.878) and histologically (vertical p = 0.940 and horizontal p = 0.862). While showing greater disinfection efficiency, the application of BDD electrodes for the electrochemical disinfection of root canals does not have a greater risk of host tissue damage compared to the conventional treatment.

Background: Determining the correct apical limit for root canal treatment is essential for its success. This study evaluates the accuracy of three electronic apex locators (EALs) in locating the apical constriction (AC) in molar canals. Methods: Forty extracted human mandibular molars were scanned using micro-CT, and endodontic access cavities were created. Teeth were mounted in alginate, and three EALs-Root ZX-mini, Root ZX-II, and Sirona integrated apex locator-were used to measure the canal working length in dry canals and with EDTA gel. Micro-CT scans were performed with files in place, and the distance from the AC was calculated. Measurements within 0.1-0.5 mm were categorized as 'close'. Those extending beyond towards the major foramen were categorized as 'beyond', otherwise they were classified as 'far'. Data analysis was conducted with a level of significance set at 5%. Results: Most readings for all EALs were in the 'close' category, with significant differences between devices ( p < 0.0001). Root ZX-mini and Root ZX-II had 74.4% and 72.5% 'close' readings, respectively, versus 51% for Sirona integrated. Accuracy did not differ significantly between dry and EDTA-treated canals ( p = 0.306). All EALs demonstrated excellent operator reliability (ICC 0.996-1.00). Conclusions: All EALs accurately determined AC, unaffected by lubricants. However, Root ZX-mini and Root ZX-II outperformed Sirona integrated. All EALs showed consistent reliability.

The critically important preoperative and intraoperative factors that affect the success of endodontic microsurgery (EMS) in Japanese patients are not defined. We conducted a retrospective study that analyzed treatment outcomes for 46 teeth in 46 Japanese patients. Treatment was provided between March 2013 and March 2015. All patients were evaluated after one year, the shortest time period over which treatment outcomes after apicoectomy could be evaluated and in which there were complete records for the recruited patient population. Healing was assessed on the basis of clinical symptoms and radiographs. With the use of a binary logistic regression model to quantify success, we estimated the effects of patient age, sex, dental arch, lesion size, lesion type, preoperative root canal treatment, the presence or absence of a post core, and the presence or absence of an isthmus on the surgically prepared dentine surface. The overall success for EMS was 93.5% after one year; failures comprised 6.5%. Successful outcomes were higher ( p = 0.04) for maxillary teeth than for mandibular teeth. Success was higher ( p = 0.019) for patients who received root canal instrumentation prior to EMS. Age, sex, lesion size, lesion type, the presence or absence of a post core, and the presence or absence of a root canal isthmus had no effect ( p > 0.2) on success. We conclude that the percentage of successful outcomes after EMS treatment for Japanese patients presenting with periapical periodontitis is very high after one year and that success is influenced strongly by the dental arch and preoperative root canal instrumentation.

The introduction of nickel-titanium rotary instruments revolutionized shaping procedures as they were able to produce a well-tapered preparation while reducing operator fatigue. The major drawback of rotary instruments was the high risk of fracture due to bending and torsional stress. Thus, the creation of a glide path has been advocated and recommended by most rotary instrument manufacturers. The aim of the present review is to summarize existing knowledge on glide path preparation and identify areas where further research is needed. The primary goal is to provide a comprehensive overview of the techniques and instruments used in glide path preparation, highlighting their advantages and limitations. The secondary goal is to explore the effect of glide path creation on the overall success of endodontic treatment, particularly in terms of reducing procedural errors and improving treatment outcomes. An online search on PubMed, ScienceDirect, UCLA, and Scopus databases was conducted, and 116 articles were identified. Eligible articles were divided into nine categories based on what they researched and compared. The categories included centering ability and/or root canal transportation, cyclic fatigue resistance, glide path and shaping time, tortional stress resistance, apical extrusion of debris and/or bacteria, defects in dentine walls, file separation, postoperative pain assessment, and scouting ability and performance. Establishing a glide path reduces root canal transportation, especially with rotary methods. Reciprocating and heat-treated files offer higher fatigue resistance and shorter preparation time. Instruments with shorter pitch lengths have greater torsional strength. Preparation and coronal preflaring reduce apical debris and bacteria. Glide paths do not affect dentine microcracks, file separation, or defects but reduce immediate postoperative pain and improve cutting ability. Randomized trials are needed to assess their impact on treatment outcomes.

As indicated by standards of modern dentistry, the essence of endodontic treatment is chemo-mechanical disinfection of the root canal system. The vital element of this process is the irrigation of canals with designated solutions as well as activating them. This review article summarizes various techniques of activation of irrigants for endodontic treatment such as manual activation, thermal, pressure, sonic, ultrasonic, and laser techniques in order to compare them. Results were gathered using PubMed, Scopus, Web of Science, and Google Scholar databases by searching keywords: activation, irrigation, irrigation protocols, and sodium hypochlorite.

This article aims to explore the importance of multimethod research in assessing the performance of nickel-titanium (NiTi) endodontic instruments. The review highlights the limitations of relying solely on measurements obtained through a narrow set of mechanical tests and acknowledges the challenge of replicating real-world working conditions in controlled laboratory settings. While achieving a perfect simulation may be difficult, the focus should be on developing research strategies that provide a superior understanding of outcomes. The multimethod research, which combines qualitative and quantitative methodologies, offers a promising solution to address this challenge effectively. By integrating nonquantifiable data with quantitative measurements, researchers may overcome the limitations of individual methodologies and gain deeper and more comprehensive insights into instrument performance. This multimethod approach enables a more accurate interpretation of results, enhancing the validity of the methodology. Therefore, conducting a comprehensive analysis of various competencies displayed by NiTi systems is essential for a comprehensive understanding of their characteristics, including cyclic fatigue, torsional and bending resistance, cutting efficiency, microhardness, design analysis, element composition, phase transformation temperatures, shaping ability, and additional methodologies that can address specific inquiries. By combining qualitative and quantitative methodologies in a multimethod approach, researchers can enhance their ability to answer research questions and provide valuable insights for clinical practice.

The aim of the study was to evaluate the effect of various silane coupling agents on the micro-push-out bond strength between a hydrogen peroxide-etched epoxy-based fiber-reinforced post and composite resin core. Seventy-five cross-linked epoxy-based fiber-reinforced posts were etched with 24% hydrogen peroxide for 10 min. Then they were divided into five groups according to various silane coupling agents and bonded to a composite core. A Universal Testing Machine was utilized to evaluate the push-out bond strength. In addition, all groups’ modes of failure were assessed. The push-out bond strength data in MPa were analyzed using ANOVA and a Tukey HSD post hoc test to reveal any difference between the groups. Results revealed that the application of a two-bottle silane coupling agent exhibited the highest bond strength, while the application of a one-bottle silane coupling agent demonstrated the lowest bond strength for a hydrogen peroxide-etched fiber post bonded to a composite core material, which was statistically significant (p < 0.05). The strongest association with the highest bond strength was found with the two-bottle silane coupling agent when compared to the one-bottle. The study highlighted that the application of a silane-coupling agent may affect the bond strength between composite and epoxy-based fiber-reinforced posts.

Enterococcus faecalis (E. faecalis), a gram-positive facultative anaerobic bacterium, is likely to survive root canal treatment because of its extremely high alkaline tolerance, which may contribute to the refractory nature of apical periodontitis (AP). In this study, protamine was combined with calcium hydroxide to evaluate its efficacy in killing E. faecalis. First, the antibacterial activity of protamine against E. faecalis was investigated. Protamine reduced the E. faecalis growth rate at concentrations above the MIC (250 μg/mL), but was not bactericidal at any of the concentrations tested. Next, we investigated the calcium hydroxide tolerance of E. faecalis, using a 10% 310 medium, adjusted for pH by adding a calcium hydroxide solution. The results showed that E. faecalis could survive and proliferate in alkaline environments up to pH 10. However, the complete killing of E. faecalis was observed when protamine (250 μg/mL) was added. In addition, compared with treatment with protamine and calcium hydroxide alone, membrane damage and internalization of protamine into the cytoplasm of E. faecalis were enhanced. Therefore, the synergistic increase in antibacterial activity may be related to the action of both antimicrobial agents on the cell membrane. In conclusion, co-treatment with protamine and calcium hydroxide seems to be very effective in sterilizing E. faecalis, and has the potential to provide a novel control method against E. faecalis for root canal treatment.

Most mandibular second molars are usually found to have either one or two roots. However, mandibular second molars can also present with variations in the number of roots as well as differences in the morphology of their root canals. An 18-year-old male presented to the Department of Graduate Endodontics clinic with a morphologically variable mandibular second molar with three roots—two mesial and one distal. Two periapical radiographs were taken at different angles, revealing that there were three different canals in separate roots, each with independent portals of exit. This is a rare anatomical configuration. The success of endodontic treatment depends on accurate diagnosis, careful examination, identification of additional roots and canals, as well as detection of variations in root canal morphology. Failing to recognize these variations may lead to failures of root canal treatments and thus unsuccessful endodontic treatment.

(1) Apical periodontitis (AP) is the inflammatory response of the periapical tissue to bacterial antigens and toxins arriving from inside the root canal after pulp necrosis. To control AP, it is necessary to interrupt the passage of antigens from the root canal to the periapex, which is achieved via a root canal treatment (RCT), which is the indicated endodontic therapy in cases of AP. The prevalence of root-filled teeth (RFT) is an indicator of the frequency of endodontic infections and the degree of dental care. Diabetes is associated with AP and has been identified as the main prognostic factor in RCT. The aim of this study was to carry out a systematic review with meta-analysis answering the following question: What is the prevalence of RFT among diabetic patients? (2) This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines 2020. A literature search was undertaken without limits on time or language until 12 January 2023 in PubMed-MEDLINE, Embase and Scielo. All studies reporting the prevalence of RFT among diabetic patients via radiographic examination; both panoramic and periapical radiographs were included. Meta-analyses were calculated with Open Meta Analyst software. The main outcome variable was the prevalence of RFT, calculated as the total number of RFT divided by the total number of teeth, which is expressed as a percentage. As a secondary outcome variable, the prevalence of diabetic patients with at least one RFT, expressed as a percentage, was also calculated. The quality of evidence of the included studies was analyzed according to the guidelines provided by the Centre for Evidence-Based Medicine in Oxford. The risk of bias was assessed using the Newcastle–Ottawa Scale, which was adapted for cross-sectional studies. To estimate the variance and heterogeneity amongst the trials, the Higgings I2 test was employed. (3) Eight studies fulfilled the inclusion criteria. Four studies were classified as having a high risk of bias, and four were classified as having a moderate risk of bias. The prevalence of RFT was estimated for 37,922 teeth and 1532 diabetic patients. The overall calculated prevalence of RFT among diabetic patients was 5.5% (95% CI = 4.1–6.9%; p < 0.001). The percentage of diabetics who had at least one RFT was 42.7% (95% CI = 23.9–61.4%; p < 0.001). (4) This systematic review and meta-analysis concluded that the prevalence of RFT among diabetic patients is 5.5%. More than 40% of diabetics have at least one RFT. In daily clinics, dentists should suspect that patients are undiagnosed diabetics when multiple RCT failures are observed in the same patient.

The priority of modern dentistry is to keep patients’ teeth for as long as possible. Tooth extraction is a procedure performed as a last resort when conservative methods and endodontic surgery procedures have not brought the expected results. As a consequence, the number of patients in dental offices, who require first and repeated endodontic treatment, is increasing. Thus, the development of new technologies in the medical industry, including microscopy, computer tomography (CT), as well as diode and neodymium-YAG-erbium lasers, enables dentists to increase the percentage of successful treatments. Moreover, mixed reality (MR) is a very new technology, in which the 3D view can help plan or simulate various types of tasks before they will be carried out in real life. In dentistry, 3D holography can be applied to display CT data to plan endodontic treatment. The most important element in effective root canal treatment is the precise imaging of the root canal. The CT scans allow dentists to view the anatomy of the patient’s tooth with much higher precision and understanding than using 2D radiography (RTG-radiographic photo) pictures. Recently, the development of new 3D technologies allows dentists to obtain even more data from existing CT scans. In this paper, the CT scan data were applied to generate patient teeth in 3D and simulate the view of the root canal’s anatomy in MR devices, i.e., Microsoft HoloLens 2. Using DICOM RAW data from the CT exam, we generated a 3D model of the jaw with a tooth. In the next step, the crown of the tooth was removed in a similar way to how a dentist would do this using a dental handpiece. Furthermore, all root canals were cleaned of everything inside. This way we achieved empty tunnels, namely root canals. Finally, we added appropriate lighting, similar to the type of lighting that dentists use. The proposed approach enables to display of the root canals in the same way as during the endodontic procedure using a microscope. It allows for the visualization of the root canal and changing its direction, in which dimensional accuracy is crucial. It turns out that mixed reality can be considered a complementary method to the traditional approach, which reduces the amount of time for the root canal treatment procedure by up to 72.25%, depending on the complexity of the case, and increases its effectiveness. Thus, the mixed reality-based system can be considered an effective tool for planning dental treatment.

Patients with a high level of anxiety anticipate extremely intense pain during dental treatment and frequently avoid visiting dentists, showing a tendency to become caught in a vicious circle of pain–anxiety–avoidance. This research aimed to examine whether dental anxiety mediates the impact of pain anticipation before endodontic treatment in the subjective avoidance of future treatments as a function of positive affect (moderating variable). One hundred consecutive patients that required endodontic therapy were enrolled in this study. In this prospective observational study, patients had to fill out a questionnaire twice: (a) first, prior to treatment (a baseline measurement including pain anticipation, MDAS (dental anxiety), PANAS (positive affect), ASA-PS (physical health), previous medication, an assessment form, and pulpal/periapical status); (b) second, once treatment had ended, the patients were registered for subjective avoidance and their number of canals of treated teeth. The results showed a significant correlation between pain anticipation, dental anxiety, and subjective avoidance; furthermore, the index of the association between pain anticipation and dental anxiety was diminished at higher levels of positive affect. In conclusion, there does not seem to be a direct and deterministic association between pain anticipation, dental anxiety, and subjective avoidance, but rather this relationship would depend on the possible influence of the personality variables of the patients.

Apical periodontitis is an inflammation leading to the injury and destruction of periradicular tissues. It is a sequence of events that starts from root canal infection, endodontic treatment, caries, or other dental interventions. Enterococcus faecalis is a ubiquitous oral pathogen that is challenging to eradicate because of biofilm formation during tooth infection. This study evaluated a hydrolase (CEL) from the fungus Trichoderma reesei combined with amoxicillin/clavulanic acid as a treatment against a clinical E. faecalis strain. Electron microscopy was used to visualize the structure modification of the extracellular polymeric substances. Biofilms were developed on human dental apices using standardized bioreactors to evaluate the antibiofilm activity of the treatment. Calcein and ethidium homodimer assays were used to evaluate the cytotoxic activity in human fibroblasts. In contrast, the human-derived monocytic cell line (THP-1) was used to evaluate the immunological response of CEL. In addition, the secretion of the pro-inflammatory cytokines IL-6 and TNF-α and the anti-inflammatory cytokine IL-10 were measured by ELISA. The results demonstrated that CEL did not induce the secretion of IL-6 and TNF-α when compared with lipopolysaccharide used as a positive control. Furthermore, the treatment combining CEL with amoxicillin/clavulanic acid showed excellent antibiofilm activity, with a 91.4% reduction in CFU on apical biofilms and a 97.6% reduction in the microcolonies. The results of this study could be used to develop a treatment to help eradicate persistent E. faecalis in apical periodontitis.

The long-term success of root canal treatment requires the prevention of bacterial leakage between canal walls and root canal obturation. In this study, we compared the leakage of Enterococcus faecalis in thirty single-rooted mandibular premolars divided into three groups. The roots in two experimental groups were obturated using a single-cone obturation technique with two different bio-ceramic sealers (MTA Fillapex and CeraSeal) while the roots in the conventional group were obturated using the lateral condensation technique with an epoxy resin sealer (AH Plus). A bacterial leakage test was carried out using a modified microbial leakage model. In the MTA Fillapex group, 30% of the specimens showed a positive sign for bacterial leakage, while 80% of samples in the CeraSeal group leaked. In the AH Plus group, 50% of specimens had bacterial leakage in the canals. The variation of the average number of days between the groups was not found to be significantly different. Taken together, bio-ceramic sealers with single-cone obturation demonstrated comparable results to the resin-based sealer with lateral condensation technique in terms of sealing efficiency against Enterococcus faecalis. Additionally, MTA Fillapex could provide a better sealing ability than CeraSeal bio-ceramic sealer.

Background and Objectives: Smear layer forms during cleaning and shaping can obstruct the entry of both irrigant and sealant into the dentinal tubules, resulting in the accumulation of the bacteria and their byproducts. To ensure effective adhesion and better periapical healing, it is strongly advised to remove the smear layer before proceeding with root canal obturation. This study was designed to compare the efficiency of laser-activated irrigation (LAI) in removing the smear layer and debriding the most apical third of the root canal. Materials and Methods: Sixty-five extracted human teeth with straight single roots were randomly and equally divided into four laser and one control groups. Root canals in all samples were shaped using prime size TruNatomy rotary files. During preparation, each canal was irrigated with 3 mL of 3% NaOCl and 3 mL of 17% EDTA alternately, followed by the irrigation with 10 mL of distilled water to avoid the prolonged effect of EDTA and NaOCl solutions. Final irrigation of 5 mL of 17% EDTA of the root canal was done to eliminate the smear layer and was subsequently activated by an endodontic ultrasonic tip for 20 s three times (control group), a flat-end laser tip (test groups 1 and 3) or a taper-end laser tip (test groups 2 and 4) for two cycles. The time of each cycle activation was 10 s (groups 1 and 2) or 20 s (groups 3 and 4) in which the Er:YAG laser of 2940 nm was used. The laser operating parameters were 15 Hz and 50 μs pulse duration. The samples were then split longitudinally and subjected to scanning electron microscopy (SEM). Results: The remaining smear layer at the apical part of the root canals was statistically significant between the control group and the laser groups 1 (p = 0.040) and 2 (p = 0.000). Within the laser groups, the exposed tubules count was greater in the laser with the flat tip as compared with the tapered tip (Laser 1 > Laser 2 and Laser 3 > Laser 4). Finally, no significant differences in the count of debris between the laser groups and control group were observed, except for laser 4 (p < 0.05), which had the highest count of debris. Conclusion: LAI to remove debris and smear layer at the apical third of the root canal is inferior to the current ultrasonic technique. However, when using the Er:YAG LAI, it is recommended to use a flat tip design for 10 s for two cycles to ensure maximum debridement of the apical dentin surface.

The utilization of lasers has been regarded as a novel technique for the purposes of clinical use in the dental field. Recently, numerous studies have been conducted on the potential applications of laser therapy in endodontics. Moreover, due to their ablation, penetrability, and disinfection capabilities, lasers have performed well with respect to endodontic treatments, including root canal treatment, vital pulp therapy (pulp capping and pulpotomy), dentinal hypersensitivity treatment, and management of dental pain related to pulp and periradicular disease. In particular, the superiorities of laser-aided pulp therapy are emphasized through condensed clinical controlled trials, and histological studies, in this review. Moreover, the ingenious use of laser applications with respect to aiding in the acceleration of root development and the extraction of foreign matters (i.e., broken files and fiber posts) in canals has quickly become the cutting-edge trend of current research. This review offers a summary and discussion of the current literature on all the aforementioned laser applications. Moreover, the characteristics of laser devices, including erbium lasers, neodymium-doped lasers, CO2 lasers, and diode lasers, are detailed and discussed here, providing useful references for laser application in endodontics. We also focus on the different wavelengths with respect to the lasers that are applied in endodontics. High-power lasers perform well as operative instruments; in addition, low-level lasers lead to the regulation of pulp inflammation, and the promotion of pulp healing. This narrative review provides a summary of the advanced applications of lasers in conjunction with various devices in the practice of endodontics, and aims to inspire innovative perspectives on lasers in the context of the treatment of dental diseases, especially pulp diseases, in the future.

This study aimed to determine the incidence of dentinal microcracks after instrumenting the root canals of maxillary premolars using two novel rotary instrumentation systems. Micro-computed tomography (microCT) scans and images generated by sectioning and observation with a stereomicroscope were used to assess the specimens. Twenty-two freshly extracted maxillary premolars were collected and the specimens were divided into two groups of eleven. The tested radicular shaping systems were XP-Endo shaper and TRUShape (i.e., single file). The specimens were scanned with microCT pre- and post-instrumentation, and the newly formed microcracks were detected. The post-instrumentation scans were also compared with images obtained by sectioning method and stereomicroscope inspection, comparing the incidence of microcracks in either microCT scans or images. The results identified an overall incidence of 0.49% of newly formed microcracks, with no statistically significant differences (p = 0.689) between the shaping systems (0.11% for TRUShape and 0.87% for XP-Endo shaper). There were statistically significant differences (p < 0.001) between the microcracks incidence in microCT scans and the sectioning method (16.6% more for the latter). In conclusion, the results show that neither TRUShape nor XP-Endo shaper created dentinal microcracks during root canal instrumentation. The sectioning method with stereomicroscope evaluation overestimates the presence of microcracks with a statistically significant difference compared to microCT scans.

Root canal treatment (RCT) eliminates damaged pulpal tissue and protects the tooth from recurrent microbial invasion. Post-endodontic pain (PEP) is a frequently encountered complication of root canal therapy. It can have an impact on patients’ quality of life (QoL) and their subjective perception of treatment options. Thus, a self-assessment questionnaire was used to evaluate and compare the influence of manual, rotary, and reciprocating file shaping procedures on immediate post-operative quality of life (POQoL) involving single-visit root canal therapy. It was a double-blinded, randomized, controlled clinical trial. A total of 120 participants were randomly assigned sequentially to three groups comprising 40 patients in each group: Group A: Hand K file (positive control); Group B: ProTaper Next file system; and Group C: WaveOne Gold. Post-operative pain was evaluated using a 4-point visual analog scale (VAS) after 12 h, 24 h, 48 h, 72 h, and 1 week. The highest post-operative pain was with manual instrumentation using hand K files, and the lowest was with reciprocating and rotating instrumentations. No significant difference was noted between the parameters of quality of life assessed, suggesting the filing system or technique had a similar effect.

Technological advancements in health sciences have led to enormous developments in artificial intelligence (AI) models designed for application in health sectors. This article aimed at reporting on the application and performances of AI models that have been designed for application in endodontics. Renowned online databases, primarily PubMed, Scopus, Web of Science, Embase, and Cochrane and secondarily Google Scholar and the Saudi Digital Library, were accessed for articles relevant to the research question that were published from 1 January 2000 to 30 November 2022. In the last 5 years, there has been a significant increase in the number of articles reporting on AI models applied for endodontics. AI models have been developed for determining working length, vertical root fractures, root canal failures, root morphology, and thrust force and torque in canal preparation; detecting pulpal diseases; detecting and diagnosing periapical lesions; predicting postoperative pain, curative effect after treatment, and case difficulty; and segmenting pulp cavities. Most of the included studies (n = 21) were developed using convolutional neural networks. Among the included studies. datasets that were used were mostly cone-beam computed tomography images, followed by periapical radiographs and panoramic radiographs. Thirty-seven original research articles that fulfilled the eligibility criteria were critically assessed in accordance with QUADAS-2 guidelines, which revealed a low risk of bias in the patient selection domain in most of the studies (risk of bias: 90%; applicability: 70%). The certainty of the evidence was assessed using the GRADE approach. These models can be used as supplementary tools in clinical practice in order to expedite the clinical decision-making process and enhance the treatment modality and clinical operation.

Endodontic disease with formation of periapical lesions (PALs) is one of the most common causes of chronic odontogenic sinusitis (ODS). It requires close collaboration between otolaryngologists and dentists, but the best sequence of management is still unknown. The aim of the present study is to clarify how radiological characteristics of teeth with PALs and previous root-canal treatment (RCT) influence the clinical evolution of the disease and to define the predictive value of its radiological and endoscopic features in determining the need for further surgical intervention. A total of 68 symptomatic patients with ODS with PALs were included in the study. The evaluation was performed by an otolaryngologist and a dentist based on a medical interview, nasal endoscopy, cold pulp testing and tomography images. Patients were prospectively followed for at least 12 months, during which nasal steroids, saline irrigations and RCT were administered. The criteria of disease improvement were: decrease of symptoms, healed sinonasal mucosa in endoscopy and radiological resolution of periapical radiolucency and sinus inflammation. Results showed that 9 (13%) patients improved after conservative treatment and 59 (87%) required further surgical intervention. Patients who improved after medical treatment and RCT were younger (p = 0.043) and had a greater distance from the top of the periapical lesion to the maxillary sinus’ floor (p = 0.003). When expansion of PALs and bone destruction toward the maxillary sinus was observed on radiological imaging (p = 0.041), and when more than one tooth root was affected (p = 0.004), patients were more likely to require surgical intervention. In conclusion, the more roots that are affected and the closer the top of the PAL is to the maxillary sinus’ floor, the greater the possibility of medical treatment and RCT failure. When the bone destruction extends into the maxillary sinus, patients eventually require both tooth extraction and FESS in order to resolve ODS completely.

To evaluate the mean distance and differences between posterior maxillary teeth and maxillary sinus floor (MSF) concerning the age and gender of the patients, a total of 124 maxillary sinuses and 496 posterior maxillary teeth were randomly selected in 62 cone-beam computed tomography (CBCT) images. Mean distances between posterior maxillary roots (PMRs) from different teeth and the MSF were measured using a calibrated tool in the software. Other relations regarding the gender and age of the patients were determined. The mean root–MSF distances in the right and left first premolars were more significant compared to the second premolars. No significant relation was found between the apices of the right and left first and second molar roots and the floor of the maxillary sinus concerning gender. A statistically significant relation was found between the apices of the buccal root of the right first premolar, right and left first and second molars and floor of the maxillary sinus concerning the age group 21–40 years (p-value = 0.009). This study showed that the second molar mesiobuccal root apex is frequently related to the sinus floor. Differences were reported concerning age, concerning the distance between posterior maxillary teeth and the maxillary sinus floor. CBCT technology helped provide the clinical proximity between the MSF and the posterior teeth root apices during the treatment planning.

The need to perform fast, effective and efficient pulpectomies has led to the development of numerous valid rotary systems. Its technical features allow the clinician to obtain good results in less working time. The objective of this study is to compare the characteristics of the different current rotary systems to favor a correct diagnosis and subsequent treatment. A systematic review of the literature has been carried out in accordance with the PRISMA recommendations. A search was carried out in PubMed, Embase Scopus, Cochrane and Web of Science databases, and was completed with a manual search. The following variables were extracted from the selected studies: author, year, sample, rotary systems used (length, diameter, taper, speed), obturation material and irrigant. From the initial electronic search of the five databases, 315 articles were identified. Once the duplicate articles were eliminated, a total of 233 remained. After reading both title and abstract, 200 articles were eliminated, leaving 33. On account of reading the full text, 22 were eliminated for not answering the research question or the inclusion criteria, leaving a total of 11 articles for the systematic review. Rotary systems which are able to adapt to the root anatomy of primary teeth and allow rapid and simple instrumentation, without producing excessive extrusion of debris at the root apex, will be the ones that provide the best results to the pediatric dentist during the performance of pulp treatment in primary teeth. Clinical success will only be achieved through proper prior diagnosis.

The primary aim of this literature review is to delineate the key inflammatory cytokines involved in the pathophysiology of pulp inflammation. By elucidating the roles of these cytokines, a deeper comprehension of the distinct stages of inflamed pulp can be attained, thereby facilitating more accurate diagnostic strategies in endodontics. The PRISMA statement and Cochrane handbook were used for the search strategy. The keywords were created based on the review question using the PICO framework. The relevant studies were meticulously assessed according to predefined inclusion and exclusion criteria for this systematic review. A rigorous quality checklist was implemented to evaluate each included study, ensuring scrutiny for both quality and risk-of-bias assessments. The initial pilot search conducted on PubMed, Scopus, Cochrane, and WoS databases yielded 9 pertinent articles. Within these articles, multiple cytokines were identified and discussed as potential candidates for use in endodontic diagnosis, notably including IL-8, IL-6, TNF-α, and IL-2. These cytokines have been highlighted due to their significant roles in the inflammatory processes associated with pulp pathology. The identification of specific inflammatory cytokines holds promise for enhancing endodontic diagnostic procedures and exploring diverse treatment modalities. However, the current body of research in this area remains limited. Further comprehensive studies are warranted to fully elucidate the potential of cytokines in refining diagnostic techniques in endodontics.

The fracture of nickel-titanium (Ni-Ti) instruments during root canal instrumentation leads to compromised outcomes in endodontic treatments. Despite the significant impact of instrument facture during a root canal treatment, there is still no universally accepted method to address this complication. Several previous studies have shown the ability of a Neodymium: Yttrium-Aluminum-Perovskite (Nd: YAP) laser to cut endodontic files. This study aims to determine safe irradiation conditions for a clinical procedure involving the use of a Neodymium: Yttrium-Aluminum-Perovskite (Nd: YAP) laser for removing fractured nickel-titanium files in root canals. A total of 54 extracted permanent human teeth ( n = 54) were used. This study involved nine distinct groups, each employing different irradiation conditions. Groups 1 s, 3 s, 5 s, 10 s, and 15 s simply consist of irradiation for 1, 3, 5, 10, and 15 s, respectively. After identifying the longest and safest duration time, four additional groups were proposed (labeled A, B, C, and D). Group A was composed of three series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT). Group B consisted of three series of irradiations of 5 s each separated by a rest time of 60 s (L5s + 60 s RT). Group C consisted of two series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT), and group D consisted of two series of irradiations of 5 s each separated by a rest time of 5 s (L5s + 5 s RT). In all groups, during the rest time, continuous irrigation with 2.5 mL of sodium hypochlorite (3% NaOCl) was carried out. The variation in temperature during irradiation was registered with a thermocouple during irradiation with different protocols. The mean and standard deviation of the temperature increase was noted. The calculation of the temperature was made as the Δ of the highest recorded temperature at the root surface minus (-) that recorded at baseline (37°). Additionally, scanning electron microscopy (SEM) was used after irradiation in all groups in order to assess the morphological changes in the root dentinal walls. The Nd: YAP laser irradiation parameters were a power of 3W, an energy of 300 mJ per pulse, a fiber diameter of 200 µm, a pulsed mode of irradiation with a frequency of 10 Hz, a pulse duration of 150 µs, and an energy density of 955.41 J/cm 2 . Our results show that the safest protocol for bypassing and/or removing broken instruments involves three series of irradiation of 5 s each with a rest time of 30 s between each series. Furthermore, our results suggest that continuous irradiation for 10 s or more may be harmful for periodontal tissue., Competing Interests: The authors declare no conflicts of interest.

Background: Various irrigation techniques for cleansing the endodontic space have been proposed, and internal heating combined with ultrasonic activation (3D cleaning technique) is considered an effective technique. This prospective multicenter clinical study aims to evaluate healing rates for teeth after root canal treatment utilizing the 3D cleaning technique and to report predictive values for success. Material and Methods: Ninety patients referred for a root canal treatment were included. All enrolled patients were treated with the 3D cleaning protocol. Four endodontists performed the clinical procedures and follow-up evaluations. Preoperative, postoperative and follow-up data were gathered from the consented patients. Each patient was assessed for any clinical signs or symptoms. Afterwards, two trained, blinded, and independent evaluators scored the subject’s periapical radiographs. This score was made by checking for the presence or absence of apical periodontitis using the periapical index (PAI). Then, the teeth were classified as healing or healed and were considered a success based on a cumulative success rate of healing. Statistical analysis was performed using the Fisher’s exact test, Pearson correlation, and logistic regression analyses of the preoperative prognostic factors at a 0.05 significance level. Results: 90 patients were evaluated at two years with a follow-up rate of 97.7%. The cumulative success rate of healing was 95.4%. Eight predicting aspects were identified by employing bivariate analyses. Then, using logistic analyses, the two prognostic significant variables directly correlated to healing were the preoperative presence of periapical index (p value = 0.016). Conclusions: In this two-year clinical study, the cumulative success rate of healing was 95.4% when patients were treated with the 3D cleaning protocol.

The need for controlling bacteria and pain during root canal therapy is undeniable. This clinical trial aimed to assess whether there is a difference in colony-forming unit (CFU) reduction after instrumentation and post-endodontic pain after root canal treatment (RCT) using a traditional endodontic cavity (TEC) versus a conservative endodontic cavity (CEC). This clinical study was conducted on 89 patients designated for a single-visit RCT. Patients were allocated randomly (TEC n = 45 and CEC n = 44). The access opening was gained accordingly in each group by a single operator. A pre-instrumentation sample of root canal dentin was collected using an endodontic file; the second sample was collected similarly, right after shaping and cleaning the root canal. The CFU was calculated based on the samples collected. The pain level was recorded preoperatively and at 1, 7, and 21 days postoperatively utilizing a visual analog scale (VAS). There were no statistically significant differences in the CFU reduction between the TEC and CEC groups ( p > 0.05). Additionally, there were no statistically significant differences found in postoperative pain levels between the TEC and CEC at 1, 7, and 21 days ( p > 0.05). Despite the limitations of this study, both the CEC and TEC demonstrate a decrease in bacteria within the root canals and alleviate postoperative pain with no difference between them.

The main goal of root canal treatment (RCT) is to eradicate or essentially diminish the microbial population within the root canal system and to prevent reinfection by a proper chemo-mechanical preparation and hermetic final obturation of the root canal space. The aim of this study was to assess the quality of the root canal filling and the number of visits needed for completing RCT by operators with different experience, including dentistry students (4th and 5th year), general dental practitioners (GDPs), and endodontists. Data from medical records of 798 patients were analyzed, obtaining 900 teeth and 1773 obturated canals according to the inclusion and exclusion criteria. A similar number of teeth was assessed in each group in terms of density and length of root canal filling and number of visits. The larger number of visits and the lower quality of treatment was observed for 4th year students than for other groups (p < 0.05); in contrast, the endodontists needed the lowest number of visits to complete RCT and more often overfilled teeth than other operator groups (p < 0.05). Interestingly, no statistical difference in quality of root canal filling was noted between 5th year students, GPDs and endodontists. The treatment of lower teeth demanded statistically more visits than that of upper teeth (p < 0.05). The results of the study emphasize that most of the root canal filling performed by operators was considered adequate, regardless of tooth type, files used and number of visits.

The success of endodontic treatment relies on both apical and coronal sealing. To achieve a good three-dimensional seal, the removal of the smear layer becomes mandatory. This study aims to assess the difference in debris accumulation and smear layer formation while using automated root canal irrigation and conventional syringe needle irrigation. Single-rooted human mandibular premolar teeth (n = 30) which were indicated for orthodontic extractions were selected. An endodontic access cavity was prepared, and a glide path was created. Based on the irrigation protocol decided upon for the study, the teeth were randomly allocated into three study groups, namely Group 1, where the manual syringe needle irrigation method was adopted; Group 2, in which automated root canal irrigation was undertaken; and Group 3, in which teeth remained un-instrumented as it was considered the Control group. The teeth were decoronated at the cement-enamel junction (CEJ) and were subjected for scanning electron microscopy (SEM) examination. Debris and smear layers were viewed in 1000× magnification and scored. A statistically significant (p < 0.05) lower mean debris and smear layer score (p < 0.05) was observed in both study groups when compared with the control group. However, no significant difference (p > 0.05) in the debris and smear layer was observed between the manual syringe needle irrigation and automated irrigation, although automated irrigation devices can be a potential alternative. The present study concluded that the efficacy of smear layer removal remained the same with both automated irrigation and manual syringe irrigation.

Background: The relationship between chronic inflammatory diseases and their comorbidities and correlation with periodontal diseases has become an increasing focus of research. Objectives: The aim of this case-control study was to conclude if patients suffering from COPD (Chronic Obstructive Pulmonary Disease) tend to have more AP (Apical Periodontitis) than non-COPD patients. Materials and Methods: The study was conducted on 30 patients assigned as cases, associated with 30 control patients linked by age (+/−5 years) and sex. Results: A total of 60 patients were recorded, and a total of 12 radiographic variables were analyzed. A total of 43 (71.7%) patients were registered with PAI (Periapical Index) ≥ 3, and there was a slightly tendency in the patients from the control group 22 (73.3%) compared to those from the cases 21 (70%), respectively (p > 0.05). Conclusions: It was concluded that there was not a significant association between the levels of PAI (Periapical Index) ≥ 3 per patient in those suffering from COPD. In fact, it could be concluded that patients diagnosed with COPD tend to have more teeth with PAI ≥ 3, more endodontic treatments and their periodontitis tended to accumulate more caries. Clinical Significance: This study establishes, in a case-control study, some specific aspects of oral health in patients with COPD, as well as analyzing the importance of oral health in this disease.

The aim of this study is to assess the surface alterations of four reciprocating instruments before and after the shaping of four resin-simulated root canals. The following four different reciprocating instruments are selected: 10 Reciproc Blue (RB25), 10 WaveOne Gold (WOG), 10 EdgeOne Fire (EOF) and 10 recently introduced instruments OneRECI (OR), for a total of 40 new instruments. Before root canal shaping, each instrument is mounted on a stub in a standardized position and observed using a scanning electron microscope (SEM) to detect any surface alteration, such as microfractures, metal defects, deformations, blunt and disruption of cutting edges, debris, pitting and tip flattening. Micrographs are acquired at the level of the tip, 4 mm, 8 mm and 12 mm from it. After that, each instrument is used in four simulated resin root canals. SEM observation was repeated after the simulated clinical use to assess the wear resistance of the instruments. Surface alterations are registered before and after instrumentation and statistical analysis is performed using a Chi-Square test to verify homogeneity of defects distribution and GLM to evaluate the differences of RMS at baseline and after use for both groups (α level 0.05). Before simulated clinical uses, no alterations are found except for three cases of EOF with metal strips in correspondence to the tip, disruption of the cutting edge of WOG and oily spotting on two different OR. After simulated clinical use, EOF shows a statistically significant difference in terms of spiral distortion and flattening of the cutting edges. The OR shows the highest presence of debris despite the ultrasonic cleaning procedures. No instrument fractures are observed. EOF should be discarded after four clinical uses and carefully inspected after each insertion into root canals. Moreover, tough attention should be paid during disinfection and cleaning procedures after instrumentation considering the copious debris detected in each instrument, particularly in OR.

Epoxy resin-based sealers are commonly used for successful endodontic treatment. This study aimed to evaluate the cytotoxicity and genotoxicity of epoxy resin-based sealers under unset and set conditions. Three epoxy resin-based sealers were used: Adseal, AH Plus, and Dia-Proseal. To test cytotoxicity, an agar overlay test and a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay were performed using unset and set sealers on L929 mouse fibroblasts. The genotoxicity test of the comet assay was performed using the same cell line. Extract dilutions in the culture media were used as test materials for the MTT and comet assays. The comet tail produced by the damaged DNA was calculated by image analyses. Statistical analyses were performed using one-way analysis of variance and Tukey’s post hoc test. Unset sealers did not show defined decolorized areas. Hardened specimens of resin-based sealers showed circular discolored zones in the agar overlay test. Dia-Proseal was the least cytotoxic after hardening. These results were confirmed in the MTT assay. Cell viability was significantly higher in cells treated with hardened sealers in both groups than that in cells treated with freshly mixed sealers in the MTT assay. Unset AH Plus® and Dia-Proseal™ significantly increased cell viability with decreasing dilution. Adseal™ was the least cytotoxic. Freshly mixed Adseal™ was more genotoxic when freshly mixed than when set. Unset epoxy resin-based sealers were generally more cytotoxic and genotoxic than set materials. Cytotoxicity does not always match the genotoxicity results; therefore, various test tools are required to test toxicity. It is necessary to properly evaluate the toxic effects to establish a biocompatibility test that mimics clinical conditions.

Therapeutic iodoform (CHI3) is commonly used as a root-filling material for primary teeth; however, the side effects of iodoform-containing materials, including early root resorption, have been reported. To overcome this problem, a water-soluble iodide (NaI)-incorporated root-filling material was developed. Calcium hydroxide, silicone oil, and NaI were incorporated in different weight proportions (30:30:X), and the resulting material was denoted DX (D5~D30), indicating the NaI content. As a control, iodoform instead of NaI was incorporated at a ratio of 30:30:30, and the material was denoted I30. The physicochemical (flow, film thickness, radiopacity, viscosity, water absorption, solubility, and ion releases) and biological (cytotoxicity, TRAP, ARS, and analysis of osteoclastic markers) properties were determined. The amount of iodine, sodium, and calcium ion releases and the pH were higher in D30 than I30, and the highest level of unknown extracted molecules was detected in I30. In the cell viability test, all groups except 100% D30 showed no cytotoxicity. In the 50% nontoxic extract, D30 showed decreased osteoclast formation compared with I30. In summary, NaI-incorporated materials showed adequate physicochemical properties and low osteoclast formation compared to their iodoform-counterpart. Thus, NaI-incorporated materials may be used as a substitute for iodoform-counterparts in root-filling materials after further (pre)clinical investigation.

Endodontic treatment aims to conserve teeth through removing infected tissue, disinfecting, and filling/sealing the root canal. One of the most important treatment steps is the removal of microorganisms to avoid reinfection and consequent tooth loss. Due to increased resistance to intracanal medications, new alternative procedures are needed. Thus, an intracanal medication is suggested using three bioactive glass (BG) compositions (BG1, BG2, and BG3) produced by the sol–gel method, with different molar contents of bactericidal oxides. The BGs were morphologically and physically characterized. Their ability to inhibit the growth of two oral pathogens responsible for the failure of endodontic treatments (E. faecalis and C. albicans) was also studied. The results suggest that BG2 and BG3 can inhibit the growth of E. faecalis after 48 h of incubation, and all BG samples have a significant effect on C. albicans survival.

Endodontic treatment comprises the overall management of pre-, intra- and post-operative symptoms, including post-operative endodontic pain, considered as a complication susceptible of chronicization. Post-operative pain is very common and highly unpreventable and has a multi-factorial etiology and a potential pathogenic link to the acute inflammation of the periapical area, secondary to localized chemical, mechanical, host and/or microbial damage occurring during endodontic treatment. Considering the multitude of heterogeneous technical and pharmacological approaches proposed to control post-operative endodontic pain, the present study primarily comprised an overview of systematic reviews of systematic reviews of randomized clinical trials, summarizing findings on post-operatively administered oral medications for post-operative endodontic pain control, in order to note the most effective type and dosage of such drugs. Secondarily, a narrative review of the current evidence on technical solutions to be observed during endodontic treatment procedures, to control post-operative pain, was conducted to provide integrated evidence-based clinical recommendations for optimal post-operative endodontic pain management.

In the population of individuals with a disability, mental illness patients can be uncooperative during dental treatment; thus, general anesthesia has been widely applied during dental procedures. This study aims to investigate the association between general anesthesia and the outcomes of root canal treatment in patients with disability. Teeth treatment records of patients with disability from Kaohsiung Medical University Hospital Research Database and electronic database from January 2005 to December 2018 were used in this retrospective cohort study. The authors conducted analysis comparing root canal treatment outcomes under general anesthesia and non-general anesthesia, indicated by endodontic re-treatment or post-treatment teeth extraction. Over the 9-year follow-up period, root canal treatment outcomes representing a cumulative survival rate of 87.68% and 74.51% in the general anesthesia group and non-general anesthesia group, respectively, were found. After adjustment for potential confounders, the teeth with general anesthesia showed a substantially and significantly reduced HR of root canal treatment failure at 0.24 (95% confidence interval, 0.12 to 0.49). Our study supported the notion that root canal treatment with general anesthesia may entail substantial reduction of treatment failure in patients with disability.

Since there are no reviews of the literature on this theme, the aim of this narrative review is to summarize the metallurgical tests used in endodontics, pointing out their functional use and their pros and cons and giving readers a user-friendly guide to serve as an orientation aid in the plethora of metallurgical tests. With this purpose, a literature search for articles published between January 2001 and December 2021 was conducted, using the electronic database PubMed to collect all published articles regarding the metallurgical tests used in endodontics for the evaluation of NiTi rotary instruments. The search was conducted using the following keywords: “metallurgy”, “differential scanning calorimetry” (DSC), “X-ray diffraction” (XRD), “atomic force microscopy” (AFM), “energy-dispersive X-ray spectroscopy” (EDS), “focused ion beam analysis” (FIB) and “Auger electron spectroscopy” (AES) combined with the term “endodontics” or “NiTi rotary instruments”. Considering the inclusion and exclusion criteria, of the 248 articles found, only 81 were included in the narrative review. According to the results, more than 50% of the selected articles were published in one of the two most relevant journals in endodontics: International Endodontic Journal (22.2%) and Journal of Endodontics (29.6%). The most popular metallurgical test was DSC, with 43 related articles, followed by EDS (33 articles), AFM (22 articles) and XRD (21 articles). Few studies were conducted using other tests such as FIB (2 articles), micro-Raman spectroscopy (4 articles), metallographic analysis (7 articles) and Auger electron spectroscopy (2 articles).

Background: Endodontic treatment of various forms of pulpitis with variations of root canal system anatomy should be performed with high quality. The use of various antibacterial agents is aimed at maintaining the success of endodontic treatment. The aim of this study was to evaluate the penetration and fixation of the nano-silver solution on the dentinal surface during endodontic treatment. Materials and methods: the study was carried out on 70 extracted single-rooted teeth, randomly divided into two groups. In the teeth of the first group, the smear layer was removed after canal preparation with 17% EDTA solution; in the second group, the smear layer was not removed. In both groups, for the final treatment of the canal, a colloidal 1% solution of нанo серебра nanosilver was used. Samples were cut and prepared for analysis using micro-CT, scanning electron microscopy (SEM), X-ray microanalysis and energy dispersive spectrometry (elemental mapping). Results: in 100% of cases in groups of teeth with a preserved smear layer, the ability of a 1% colloidal solution of nanosilver with particles of 1–2 nm to be fixed on dentin with a removed and preserved smear layer and to leave a film on the dentinal surface was established. In the samples with removed smear layer, silver was found in 73.5% of cases. Conclusion: The nano-silver solution with a particle size of 1–2 nm proved its ability to penetrate the dentinal surfaces and create a final film covering the dentinal surface of the root canal before applying the sealer.