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Aim: To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin. Methodology: This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty‐two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post‐surgery. Student's t‐test (p <.05) was used to compare the EPT values at baseline and T4. anova (p <.05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p <.05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response. Results: At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p >.05), but significant differences were observed for EPT values between T1 and T4 (p <.05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points. Conclusions: These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post‐surgery follow‐up with TPT and EPT is recommended to assess pulp status. [ABSTRACT FROM AUTHOR]

(1) Background: A Dynamic Navigation System (DNS) is an innovative tool that facilitates the management of complex endodontic cases. Despite the number of advantages and limitations of this approach, there is no evidence-based information about its efficiency in comparison with that of the traditional method in endodontics. (2) Objectives: We aimed to explore any beneficial effects of the DNS and compare the outcomes of DNS vs. free-hand (FH) approaches for non-surgical and microsurgical endodontics. (3) Methods: A literature search was conducted in August 2023 to identify randomized, experimental, non-surgical, and microsurgical endodontic studies that compared the DNS with FH approaches. The procedural time (ΔT, s), substance loss (ΔV, mm3), angular deviation (ΔAD, °), coronal/platform linear deviation (ΔLD_C, mm), and apical linear deviation (ΔLD_A, mm) were recorded and analyzed. Quality and risk of bias assessments were conducted according to the Quality Assessment Tool For In Vitro Studies. A meta-analysis was performed using mean difference and standard deviation for each outcome, and heterogeneity (I2) was estimated. p < 0.05 was considered significant. (4) Results: One-hundred and forty-six studies were identified following duplicate removal, and nine were included in the systematic review and meta-analysis. The overall risk of bias was classified as low. The DNS was found to be more accurate and efficient than the FH approach was, resulting in a significantly shorter operation time (p < 0.00001) and less angular (p ≤ 0.0001) and linear deviation (p ≤ 0.01). For substance loss, the advantage of the DNS was significant only for microsurgery (p = 0.65, and p < 0.005, for non-surgical and microsurgical procedures, respectively). A reduced risk of iatrogenic failure using the DNS was observed for both expert and novice operators. (5) Conclusions: The DNS appears beneficial for non-surgical and microsurgical endodontics, regardless of the operator's experience. However, appropriate training and experience are necessary to access the full advantages offered by the DNS. [ABSTRACT FROM AUTHOR]

This study investigated variation in working length during multiple‐visit endodontic treatment. Patients (N = 106) with pulpitis or pulp necrosis, with or without apical periodontitis, were included. During the first appointment, glide path was performed with ProGlider and shaping with ProTaper Next. Working length was detected four times. Working length was then re‐recorded prior to filling during the second appointment and a 0.5 mm threshold was selected as the minimum clinically meaningful variation. A logistic regression model was used to evaluate the impact of tooth anatomy, preoperative pulp status, apical periodontitis and lesions of endodontic origin on working length variation. Working length varied between first and second appointments in 34% of patients. The presence of apical periodontitis was the only variable significantly associated with variation in working length (p = 0.011). These data suggest that working length should be re‐checked prior to root canal filling to prevent procedural errors. [ABSTRACT FROM AUTHOR]

Background: Endodontic ledge (EL) formation is the most common complication of endodontic treatment. Although various etiological factors have been identified, canal curvature is the most significant variable correlated with EL formation. The aim of this micro-computed tomographic (micro-CT) study was to evaluate EL position in the mesial canals of the lower molars in relation to the degree of canal curvature. Methods: Forty intact mandibular first molars with independent mesial canals with 20°–40° primary mesio-distal curvature, 10°–30° buccal-lingual canal curvature and 4 < r ≤ 8 mm main curvature radius were selected. Working length was measured with a K-File #10 and a high resolution pre-operative micro-CT analysis was performed. Ledges were created at the point of maximum canal curvature using stainless steel K-Files #30–35, alternating irrigation with 5% NaOCl and 10% EDTA. A post-operative high-resolution micro-CT analysis was then completed. Pre- and post-operative images were analyzed. The angle (α) formed between the vector passing through the geometric center of the EL and the center of the original canal lumen and the line joining the centers of the mesio-buccal and mesio-lingual canal orifices was calculated, and a descriptive statistical analysis was achieved. The α angle values were analyzed in relation to canal curvature using Kruskal-Wallis and post hoc Dunn's tests. The level of significance was set at P < 0.05. Results: The α angles appeared inversely proportional to canal curvatures in the buccal-lingual and mesio-distal projections. The mean α angle was 36.4° (standard deviation 10.64; 95% confidence interval 34.1–40.9). Conclusion: Within the limitations of this study, endodontic ledges develop in the opposite direction to the three-dimensional canal curvature and their position is influenced by the degree of curvature. Clinically, the α angle values may be related to the recommended direction to manage endodontic ledges. [ABSTRACT FROM AUTHOR]

Featured Application: Finite element analysis is proposed as a reliable tool for the evaluation of the shaping ability of NiTi rotary instruments during an early design phase. This method could significantly reduce instrument development time and costs without the use of prototypes. The aim of this study was to evaluate the contact pressure distribution of two different nickel-titanium (NiTi) endodontic rotary instruments against the root canal walls and to virtually predict their centering ability during shaping with finite element analysis (FEA). Resin blocks simulating root canals were used. One was shaped with ProGlider and ProTaper Next (PTN) X1-X2 and one with ScoutRace and BioRace (BR) 1, 2 and 3. Both resin blocks were virtually replicated with computer-aided design (CAD) software. The endodontic instruments ProTaper Next (PTN) X2 and BioRace BR3 were also replicated with CAD. The NiTi instruments and the shaped blocks geometries were discretized and exported for FEA. The instrument rotation in the root canals was simulated. The finite element simulation was performed by applying an insertion and extraction force of 2.5 N with a constant rotational speed (300 rpm). To highlight possible differences between pressure distributions against the root canal portions outside and inside the canal curvature, the parameter Var was originally defined. Var values were systematically lower for PTN X2, revealing a better centering ability. FEA proved effective for the virtual prediction of the centering ability of NiTi instruments during an early design phase without the use of prototypes. [ABSTRACT FROM AUTHOR]

Introduction Contracted endodontic cavities (CECs) have developed from the concept of minimally invasive dentistry and provide an alternative to traditional endodontic cavities (TECs). They have been designed in an effort to preserve the mechanical stability of teeth. The contracted cavity design preserves more of the dentin but may influence the geometric shaping parameters. The aim of this micro–computed tomographic study was to evaluate the influence of contracted endodontic cavities on the preservation of the original root canal anatomy after shaping with nickel-titanium rotary instruments. Methods Thirty extracted human mandibular molars with fully formed apices and independent mesial canals were randomly assigned to group 1 (TEC) and group 2 (CEC). Each group was shaped using ProGlider (Dentsply Maillefer, Ballaigues, Switzerland) and WaveOne Gold (Dentsply Maillefer). Irrigation was performed with 10% EDTA and 5% sodium hypochlorite. Samples were scanned before and after canal shaping to match canal volumes (SkyScan; Bruker microCT, Kontich, Belgium [100 kV, 100 μA, and 15-μm resolution]), and images were analyzed to evaluate canal volumes, surface areas, and centroid shift on cross sections at −1 mm and −3 mm from the apex. Results TECs showed a greater preservation of the original root canal anatomy with less apical transportation than CECs, possibly because of the absence of coronal interferences and, therefore, fewer pecking motions required to complete instrumentation. Conclusions Within the limitations of this study, TECs may lead to a better preservation of the original canal anatomy during shaping compared with CECs, particularly at the apical level. [ABSTRACT FROM AUTHOR]

Introduction: A coronal seal is fundamental for a positive outcome to endodontic therapy. In this in vitro study, we evaluated the adaptation of composite resins in postendodontic restorations using optical coherence tomographic (OCT) imaging. Our null hypothesis was that there would be no difference in marginal adaptation to the pulp chamber floor between resin composites of different viscosities. Methods: Thirty intact upper molars extracted for periodontal reasons were selected, endodontically treated, and filled with gutta-percha. The excess gutta-percha was entirely removed from the pulp chamber floor, and teeth were randomly divided into 3 groups (n = 10) according to the material used for the restoration: group 1: 0.5-mm horizontal layer of flowable composite followed by nanohybrid composite, group 2: bulk layering of bulk fill flowable composite; and group 3: oblique layering of nanohybrid composite. The degree of adaptation to the cavity floor was assessed using OCT imaging, and images were analyzed with the software program ImageJ (National Institutes of Health, Bethesda, MD) to assess the marginal gap between the composite and the pulp chamber floor. Collected data were statistically analyzed using analysis of variance testing, and statistical significance was set at P < .05. Results: Flowable composites showed significantly better adaptation than traditional packable nanohybrid composites (P < .05). All significant differences were found between groups 1 and 2. Conclusions: Within the limitations of this OCT imaging-based in vitro study, it was concluded that the flowable composite (flow + nanofilled; flow bulk fill composite) adapted better to the pulp chamber floor than the packable nanohybrid composite resin. Further studies are necessary to confirm these results. [ABSTRACT FROM AUTHOR]

Introduction The aim of this micro–computed tomography study was to describe the shaping properties of ProGlider/ProTaper Next (PG/PTN) and ScoutRace/BioRace (SR/BR) nickel-titanium rotary systems. Methods Thirty maxillary first permanent molars were selected. Mesiobuccal canals were randomly assigned ( n = 15) to PG/PTN or SR/BR groups. Irrigation was performed with 5% NaOCl and 10% EDTA. Specimens were scanned (voxel size, 9.1 μm) for matching volumes and surface areas and post-treatment analyses. Root canal centering ability, canal geometry enlargement, and thickness of dentinal wall at inner curvature were assessed at apical level and point of maximum curvature. Results were analyzed with 4 one-way analyses of variance. Results Canal centering ability was superior in PG/PTN ( P = .006 at apical level, P = .025 at point of maximum curvature). PG/PTN demonstrated a more conservative increase of canal areas ( P = .027 at apical level, P = .038 at point of maximum curvature). Centrifugal increase in canal diameters did not significantly differ between groups ( P = .65 at apical level, P = .61 at point of maximum curvature). Inner dentinal wall thickness was less reduced with PG/PTN compared with SR/BR, with no statistical differences ( P = .23 at point of maximum curvature, P = .89 at apical level). PG/PTN shaping taper ranged between 6% and 7%. Conclusions Neither system produced significant shaping errors in curved canals. PG/PTN system showed better preservation of canal anatomy. PTN offset section did not influence final preparation taper. [ABSTRACT FROM AUTHOR]

Introduction Instrument failure caused by excessive torsional stress can be controlled by creating a manual or mechanical glide path. The ProGlider single-file system (Dentsply Maillefer, Ballaigues, Switzerland) was recently introduced to perform a mechanical glide path. This study was designed to compare the effect of a glide path performed with PathFiles (Dentsply Maillefer) and ProGlider on torque, time, and pecking motion required for ProTaper Next X1 (Dentsply Maillefer) to reach the full working length in simulated root canals. Methods Forty Endo Training Blocks (Dentsply Maillefer) were used. Twenty were prepared with a mechanical glide path using PathFiles 1 and 2 (the PathFile group), and 20 were prepared with a mechanical glide path using a ProGlider single file (the ProGlider group). All samples were shaped with ProTaper Next X1 driven by an endodontic motor connected to a digital wattmeter. The required torque for root canal instrumentation was analyzed by evaluating the electrical power consumption of the endodontic engine. Electric power consumption (mW/h), elapsed time (seconds), and number of pecking motions required to reach the full working length with ProTaper Next X1 were calculated. Differences among groups were analyzed with the parametric Student t test for independent data ( P < .05). Results Elapsed time and electric power consumption were significantly different between groups ( P = .0001 for both). ProGlider appears to perform more efficiently than PathFiles in decreasing electric power consumption of ProTaper Next X1 to reach the full working length. Conclusions This study confirmed the ability of ProGlider to reduce stress in ProTaper Next X1 during shaping through a glide path and preliminary middle and coronal preflaring. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study investigated the influence of clinical experience in relation to the efficacy and effectiveness of removal of 2 different fiber posts. Methods: In total, 48 intact single-rooted teeth were treated endodontically and obturated. Then, 10-mm post spaces were prepared, and fiber posts were luted. Twenty-four #1 D.T. Light-Posts were used in group 1, and 24 #2 Hi-Rem Prosthetic Posts were used in group 2. A pullout test (n = 8 per group) was performed by using a universal testing machine to compare bond strength. Then, fiber post removal efficacy and efficiency were tested. Each group was divided into 2 subgroups (n = 8) according to operator experience. In group 1, fiber posts were removed with an ultrasonic handpiece by using a #3 Start-X tip. In group 2, a size 25/0.04 ProFile was used to remove the central soft polymer macrofiber, and a #2 Largo drill was used to remove the fiber post and luting cement remnants. Post removal times were recorded to evaluate efficacy. Weight change was determined, and post space walls were analyzed microscopically to evaluate effectiveness. Results: Bond strength did not differ significantly (P = .7569) between post systems. Post hoc Tukey tests indicated that removal time was affected significantly by operator experience in group 1 (P < .001) but not in group 2. Weight change was affected significantly by experience level in both groups. No difference in post space wall characteristics was observed between subgroups. Conclusions: The Hi-Rem post was easier to remove than the D.T Light-Post. [Copyright &y& Elsevier]

Abstract: Introduction: There is evidence to suggest that an association exists between oral infections and coronary heart disease (CHD). Subjects presenting lesions of endodontic origin (LEOs) or pulpal inflammation had an increased risk of developing CHD. However, findings concerning systemic manifestations of apical periodontitis (AP) remain controversial. An association between CD14 gene polymorphisms and atherosclerosis-associated diseases has been shown, but there are no data regarding an association between CD14 polymorphism and AP. This study evaluated associations between clinical oral health status, CD14 polymorphisms, and CHD. Methods: A case-controlled clinical trial was designed to compare middle-aged adults with acute myocardial infarction or unstable angina (n = 51) within 12 months of the acute event defined as first manifestation with healthy controls (n = 49). Participants were matched for age, sex, and socioeconomic status. Indicators of oral disease and compliance were evaluated. CD14 polymorphisms were analyzed by restriction fragment length polymorphism–polymerase chain reaction. Results: CHD subjects had a higher prevalence of oral diseases and lower compliance to oral preventive strategies than healthy controls. Multivariate analysis showed a positive association between missing teeth (odds ratio [OR] = 1.37; 95% confidence interval [CI], 1.02–1.85), the number of LEOs (OR = 4.37; 95% CI, 1.69–11.28), chronic periodontitis (OR = 5.87; 95% CI, 1.17–29.4), and CHD. No statistically significant association emerged between the CD14 C(−260)T and the CD14 C(−159)T polymorphism, endodontic or periodontal disease, and CHD. Conclusions: Chronic oral diseases may increase the risk of CHD and may be an unconventional risk factor for CHD. [Copyright &y& Elsevier]

Abstract: Introduction: This study evaluated the influence of glide path on canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files. Methods: Thirty ISO 15, 0.02 taper Endo Training Blocks were used. In group 1, glide path was created with PathFile 1, 2, and 3 at working length, whereas in group 2, glide path was not performed. In both groups, canals were shaped with WaveOne Primary reciprocating files at working length. Preinstrumentation and postinstrumentation digital images were superimposed and processed with Matlab r2010b software to analyze the curvature radius ratio (CRr) and the relative axis error (rAe), representing canal curvature modification. Data were analyzed with 1-way balanced analyses of variance at 2 levels (P < .05). Results: Glide path was found to be extremely significant for both CRr parameter (F = 9.59; df = 1; P = .004) and rAe parameter (F = 13.55; df = 1; P = .001). Conclusions: Canal modifications seem to be significantly reduced when previous glide path is performed by using the new WaveOne nickel-titanium single-file system. [Copyright &y& Elsevier]

Abstract: Introduction: This study evaluated the working length (WL) modification after instrumentation with WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland) reciprocating files and the incidence of overinstrumentation in relation to the initial WL. Methods: Thirty-two root canals of permanent teeth were used. The angles of curvature of the canals were calculated on digital radiographs. The initial WL with K-files was transferred to the matched WaveOne Primary reciprocating files. After glide paths were established with PathFile (Dentsply Maillefer, Ballaigues, Switzerland), canals were shaped with WaveOne Primary referring to the initial WL. The difference between the postinstrumentation canal length and the initial canal length was analyzed by using a fiberoptic inspection microscope. Data were analyzed with a balanced 2-way factorial analysis of variance (P < .05). Results: Referring to the initial WL, 24 of 32 WaveOne Primary files projected beyond the experimental apical foramen (minimum–maximum, 0.14–0.76 mm). A significant decrease in the canal length after instrumentation (95% confidence interval ranging from −0.34 mm to −0.26 mm) was detected. The canal curvature significantly influenced the WL variation (F1 = 30.65, P < .001). The interaction between the initial canal length and the canal curvature was statistically significant (F2 = 4.38, P = .014). Conclusions: Checking the WL before preparation of the apical third of the root canal is recommended when using the new WaveOne NiTi single-file system. [Copyright &y& Elsevier]

In endodontically treated teeth, cuspal coverage plays a fundamental role in reducing the risk of fracture. However, the adhesive techniques with or without fiber post increased the possibilities in restoring root-filled teeth. The aim of this study was to determine the effect of the fiber post and/or post length and/or cuspal coverage on the fracture resistance of endodontically treated maxillary premolars. Seventy intact single-rooted maxillary premolars were selected and divided in seven groups of ten each: 'intact teeth' (control), 'inlay without fiber post' (G1), 'inlay with long fiber post' (G2), 'inlay with short fiber post' (G3), 'onlay without fiber post' (G4), 'onlay with long fiber post' (G5), and 'onlay with short fiber post' (G6). Except for intact teeth, all specimens were prepared with a mesio-occluso-distal (MOD) cavity, endodontically treated and restored with or without long or short post, with or without cusp coverage. All specimens were thermal-cycled, exposed to a cyclic loading, and then submitted to the static fracture resistance test. Fracture loads and mode of failure were evaluated. A statistically significant difference in fracture resistance was found between group 1 and the other groups ( p < 0.001). χ2 test showed statistically significant differences in the patterns of fractures between the groups ( p < 0.001). The highest number of favorable fractures was observed in groups 3 and 4. Similar fracture resistance was detected in maxillary premolars endodontically treated with MOD cavity preparations, restored with either direct resin composite with fiber post or cusp capping. The 'short post' direct restoration may be a valid alternative in the restoration of root-filled premolars. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to compare the effective shaping time and number of rotations required by an endodontist working with hand and rotary ProTaper instruments to completely shape simulated root canals. Eighty Endo Training Blocks (curved canal shape) were used. Manual preflaring was performed with K-Flexofiles #08-10-12-15-17 and #20 Nitiflex at a working length of 18 mm. Specimens were then randomly assigned to 2 different groups (n = 40); group 1 was shaped by using hand ProTaper and group 2 with ProTaper rotary. The number of rotations made in the canal and the effective time required to achieve complete canal shaping were recorded for each instrument. Differences between groups were analyzed with the nonparametric Mann-Whitney U test (P < .05). Hand ProTaper required significantly fewer rotations (P < .001) than rotary ProTaper, whereas the effective working time to fully shape the simulated canal was significantly higher (P < .001) with hand ProTaper. [Copyright &y& Elsevier]

Apicoectomy of the superior first molar palatine root until recently involved relatively destructive and laborious surgery because of the palatal access route, which not only necessitates an extensive flap, but also the readying of procedures required to deal with a possible hemorrhage from the palatine artery. With the advent of operative microscopy, endodontic surgery has become more precise and less invasive and its technical potential has increased; a possible innovative surgical technique may entail vestibular root access. The possibility of using low-dose, low-cost computed tomography (CT) dedicated to the jaw to obtain anatomic information to plan apicoectomy via the vestibular approach was evaluated; 31 patients were referred to CT with the NewTom apparatus. In 43 superior first molars, the mean distance of the palatine root from the external vestibular cortex was measured, and the frequency that the maxillary sinus lateral recess lay between the roots was determined. The mean root apex-vestibular cortex distance was 9.73 mm. In 25% of cases the maxillary sinus recessus lay between vestibular and palatine roots. CT may play an important role in optimizing palatine root apicoectomy through vestibular access, with regard to precision and preventing complications, with relatively low biological and economic cost, also possibly contributing to the affirmation of this new surgical procedure. [Copyright &y& Elsevier]

Introduction Methods Results Conclusion Computer simulations are stimulating increased attention in dentistry. Augmented reality superimposes a virtual scenario over an existing reality and allows interaction with it. Virtual reality (VR) simulates a fully immersive situation permitting the user to experience the full environment in real time. Haptic technology provides tactile and realistic force feedback for the user to experience the immersive situation as if they were really there. Preclinical training is important to gain familiarity with difficult surgical techniques and to implement interpersonal skills. Developing a valid assessment of surgical simulation is challenging.This paper wants to present a newly realized VR simulation in endodontic microsurgery through the developmental digital workflow, the demonstration of a haptic VR scenario and student self‐assessment and self‐reflection feedback.The volumes were exported in a stereolithography format to prepare and optimize in terms of shape and shade for the VR simulation. The graphics and touchable haptic solid were created using Virteasy Editor, which allows the transformation of 3D surfaces into graphical and volumetric haptic solids depending on their material (enamel, dentine, pulp and bone).Users were asked to execute the osteotomy and root‐resection preparation. The assessment criteria were determined, and the feedback statements were created by a questionnaire with fixed answers. Objective and qualitative criteria for assessing the preparation were obtained from the literature.This study provides proof that it is possible to provide reliable and clinically relevant qualitative feedback with a VR simulator.VR simulation offers an innovative approach with all the benefits of clinical experience. It permits you to save your own progress and review the assessment at any time. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this study was to investigate the influence of post placement on fracture resistance of endodontically treated mandibular molars restored with adhesive overlay restorations. Methods: Endodontically treated human molars with two- and one-wall cavities either underwent or did not undergo fibre post insertion within composite build-up before cementation of indirect composite onlay restorations. The specimens were thermocycled, exposed to cyclic loading, and submitted to the static fracture resistance test. Fracture loads and mode of failure were evaluated. Results: Statistical analysis revealed that specimens with fibre posts demonstrated similar failure loads (p =0.065) but more favourable fracture patterns compared with specimens without fibre posts. No difference was found between two- and one-wall cavities. Conclusions: Within the limitations of this study, the insertion of fibre posts did not improve support under indirect composite overlays. Clinical significance: When restoring heavily broken down endodontically treated mandibular molars with an indirect overlay composite restoration, the fibre post inserted within the composite build-up do not provide any increase in fracture resistance. [Copyright &y& Elsevier]