European Endodontic Journal最新文献

This report evaluated the impact of using multiple individualized endodontic access guides in the management of obliterated root canals in maxillary molars. A 70-year-old female patient presented with pain in the upper left first molar. Intraoral examination revealed an extensive resin composite restoration, with no signs of tooth mobility or marginal periodontal disease. The clinical diagnosis was symptomatic apical periodontitis. Cone beam computed tomography (CBCT) revealed a hypodense area in the mesiobuccal and palatal (P) roots, associated with signs of apical periodontitis and obliterations in the cervical and middle thirds of the first MB (MB1), second MB (MB2) and P canals. Due to the high risk of perforation, a guided approach to the canals was selected. Multiple guides were designed using digital planning software, combining CBCT images with intraoral scanning. Access cavities were created using a 25 mm long, 1.0 mm diameter surgical bur. After gaining access, the canals were instrumented, medicated with calcium hydroxide for 15 days, and obturated. Twelve months post-treatment, the patient remained asymptomatic, and the clinical results were considered satisfactory. (EEJ-2025-01-06).

Objective: This study assessed the effects of various types of procedural errors arising from root canal instru-mentation on initial root canal treatment outcomes.

Methods: This retrospective cohort study analysed data from sixth-year dental students performing initial root canal treatment on mature permanent molars between 2015 and 2019. Treatment records and radio-graphic images were reviewed to identify procedural errors during root canal instrumentation and other po-tential confounding factors affecting treatment outcomes. Subsequently, uni- and multivariate logistic regres-sion analyses were performed to identify predictors of treatment outcomes.

Results: A total of 142 teeth (343 roots) met the inclusion criteria, with an average follow-up period of 35.84+-16.72 months. According to stringent assessment criteria, overall healing rates were 72.5% for the teeth (103 of 142) and 80.5% for the roots (276 of 343). Multivariate logistic regression analysis revealed that among the procedural errors considered, only errors related to under-instrumentation (root canal deviation and lat-eral perforation) were significant predictors of treatment outcomes (p=0.002).

Conclusion: Root canal treatment outcomes are significantly influenced by procedural errors, particularly those affecting the root canal preparation length. Procedural errors related to under-instrumentation can compromise root canal disinfection and increase the risk of post-treatment disease by up to eightfold.(EEJ-2025-01-010).

Objective: Nickel-titanium (NiTi) rotary instruments have revolutionized endodontic practice through continuous advancements in metallurgy and design. Despite these improvements, mechanical failure remains a clinical concern. This study aimed to evaluate and compare the design features, metallurgical properties, and buckling resistance of five widely used NiTi rotary endodontic systems.

Methods: A total of 250 new NiTi rotary instruments from five systems (ProTaper Next, Mtwo, ProFile, EndoSequence, and GT Series X) were analyzed. Design features were assessed using dental microscopy and scanning electron microscopy. Metallurgical properties were evaluated through energy-dispersive X-ray spectroscopy and differential scanning calorimetry. Buckling resistance was measured using a universal testing machine equipped with a 1 kN load cell, applying a compressive load at 1 mm/min until 1 mm of lateral displacement was achieved. Statistical analysis was performed using the Shapiro-Wilk test to assess normality, followed by the non-parametric Kruskal-Wallis test to compare groups. A significance level of p<0.05 was adopted.

Results: ProFile instruments exhibited the highest number of spirals (19) and spiral density (1.19 spirals/mm), while GT Series X featured the shortest cutting blade length (≤12 mm). All systems demonstrated near-equiatomic nickel-titanium ratios. ProTaper Next and GT Series X showed higher R-phase and austenitic transformation temperatures. Buckling resistance was significantly greater in the ProFile (0.04 and 0.06 taper) and EndoSequence 35/.06 and 40/.06 instruments (p<0.05). In contrast, EndoSequence 0.04 files, Mtwo, and ProTaper Next exhibited lower resistance.

Conclusion: Design features, taper, and metallurgical composition significantly influence the buckling resistance of NiTi rotary endodontic instruments.

Objective: This study aimed to assess the efficacy of a novel retrograde irrigation protocol involving ultrasonic activation, compared with conventional techniques, using two complementary experimental models.

Methods: Experiment 1: Sixty extracted human mandibular premolars were endodontically prepared, obturated, and randomly assigned to three groups (n=20): Group 1 (saline irrigation), Group 2 (ultrasonically activated 17% EDTA gel and 5.25% NaOCl gel), and Group 3 (no irrigation). Following 1 mm apical resection and 3 mm retrograde cavity preparation, rootend cleanliness was assessed using scanning electron microscopy (SEM). Three calibrated, blinded examiners evaluated smear layer and debris scores. Experiment 2: A 3d-printed artificial canal system with lateral extensions containing bovine pulp tissue was used to simulate organic material. Groups received: Group 1 (saline), Group 2 (ultrasonically activated 5.25% NaOCl gel), Group 3 (no irrigation). Pulp dissolution was measured using a high-precision analytical microbalance. Data were analysed using the Kruskal-Wallis test and Dunn-Bonferroni post hoc (Experiment 1), and one-way ANOVA with Tukey HSD (Experiment 2). A significance level of p<0.05 was adopted.

Results: In Experiment 1, Group 2 showed significantly lower debris and smear layer scores than Groups 1 and 3 (p<0.001). In Experiment 2, only Group 2 achieved complete pulp tissue dissolution (p<0.001).

Conclusion: Ultrasonically activated EDTA and NaOCl gel significantly enhance cleaning efficacy and organic tissue dissolution in retrograde endodontic surgery, allowing for a more conservative apical resection approach.

Objective: This study aimed to evaluate and compare the dentinal defects caused by three different retreat-ment systems [Endostar RE Endo, XP-endo Retreatment, and MANI Gutta-Percha Removal (GPR)] and to assess the percentage of residual root canal filling material following the retreatment procedure.

Methods: Sixty extracted mandibular second premolars with straight oval canals were used. The roots were standardized to a length of 14 mm. All samples were instrumented with NiTi instruments up to size 30.04, then filled using single cone technique with AH plus sealer and gutta-percha. Four groups were created from the samples. Group 1 served as the negative control (n=15), while the remaining three groups (n=15 each) were categorized based on the retreatment system used. Stereomicroscope at magnification 45 x was used to evaluate the incidence of crack formation and propagation at apex of the roots and the residual volume percentage of root filling materials in groups of Endostar RE, MANI GPR, Xp retreatment systems assessed using CBCT. Fisher's exact test was used to analyze the incidence and propagation of cracks, while one-way ANOVA and Tukey's post hoc test were applied to assess differences in residual filling material volume among the groups P values at 0.05.

Results: There is significance difference (p=0.028) between the Endostar and Xp retreatment system. The highest of dentinal defect (1015) with Endostar retreatment system followed by (415) with GPR system and (215) with XP endo retreatment system.Highest residual filling material mean at Endostar RE retreatment system (51.97) and lowest mean (39.07) at Xp retreatment system A statistically significant difference was observed between the groups (p<0.001), particularly between the Endostar and XP retreatment systems.

Conclusion: No system was capable of completely eliminating obturated materials. The XP-endo Retreat-ment system showed the lowest incidence of crack formation and propagation and proved to be the most effective in removing gutta-percha and sealer.

A thorough understanding of tooth anatomy is essential for all endodontic therapies. Over the last two decades, technological advances in 3D imaging have revealed the complexities of root and canal anatomy. Recently, artificial intelligence (AI) models have been developed and are being applied to a range of fields within medicine and dentistry. There is an emerging trend for the application of this technology in 2D and 3D imaging tools to study the anatomical features of roots and canals. This narrative review provides a comprehensive analysis of AI applications in the study of root and canal anatomy and their implications for education, research and clinical practice. The analysis reveals that AI applications for the study and teaching of root and canal anatomy are promising; however, more investigations are warranted with larger datasets to provide more accurate deep learning models. Students, researchers and clinicians should understand the inherent limitations of AI data generated from 2D and 3D imaging devices. Future studies are needed to assess what effect deep learning models have on the diagnostic and operative clinical skills of students and dental practitioners when managing teeth with different levels of anatomical complexities.

Objective: This study investigated the residual effects of various concentrations of triple antibiotic paste (TAP) on the viability of human stem cells of the apical papilla (hSCAPs) in a 3D root canal culture model.

Methods: Sixty-four single-rooted segments were prepared and allocated into five groups (n=12): four concentrations of TAP (1 mg/ml, 2.5 mg/ml, 5 mg/ml, 10 mg/ml) and a control group with vehicle alone. TAP was prepared by mixing USP-graded antibiotic powder with vehicle (macrogol and propylene glycol). The canals were filled with the prepared medication for 28 days. After removing TAP, fibrin gels containing hSCAPs were loaded into the canal and incubated for 7 days. Cell morphology was observed using confocal laser scanning microscopy (CLSM), whilst cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTT) assay.

Results: The vehicle alone and the 1 mg/ml TAP groups showed viable and proliferative cell morphology. However, higher concentrations of TAP displayed non-proliferative cells as observed by CLSM. For the cell viability test, 1 mg/ml TAP did not demonstrate a different percentage of cell viability from the control group. However, 2.5 mg/ml, 5 mg/ml and 10 mg/ml TAP exhibited significantly lower percentages of cell viability compared with the control (p<0.001).

Conclusion: Cells can survive at low TAP concentrations of ≤1 mg/ml. However, harmful effects become evident at TAP concentrations of ≥2.5 mg/ml.

Objective: The present study aimed to evaluate the changes in the physicochemical properties of dentine after irrigation with a solution of 0.22% alendronic acid (AA) as a chelating agent compared to 17% ethylene-diaminetetraacetic acid (EDTA).

Methods: A total of 48 extracted premolars and molars that were intact, free of caries or cracks, without root canal treatment and restorations were collected. The roots were randomised into three groups (n=16): Group A: Distilled Water (dH2O); Group B: 17% EDTA, and Group C: 0.22% AA. Longitudinal sections of the dentine with a root of 1x1x10 mm were made with a diamond disc and a low-speed handpiece for bending tests (n=9). For morphological analysis, images were taken with a scanning electron microscope, crystallographic analysis with X-ray diffraction, and chemical analysis with Fourier Transform Infrared Spectroscopy (FTIR) and Vickers Hardness. For this purpose, cross-sections were made through the root using the Isomet to obtain 3 mm thick dentine discs (n=14). The samples were stored in dH2O for up to 24 h before use and dried at room temperature before exposure to chelating solutions for 1 h in a Stuart STR6D mixer at 50 rpm. For data comparison, the Kruskal-Wallis statistical test was used (α=0.05).

Results: The chelating solutions of EDTA and AA cause alterations in the physicochemical structure of dentine, attacking mainly the inorganic part (Hydroxyapatite), which was observed in the decrease in intensity of the peaks in the X-ray diffraction pattern of hydroxyapatite. This generated a greater exposure of the collagen fibres that were observed in SEM and the increase in the bands characteristic to Collagen Type I in the infrared spectrum at 1645, 1550, and 1240 cm-1 belonging to amide I (C=O), amide II (N-H) and amide III (C-N), significantly affecting its dentine hardness (p=0.001).

Conclusion: AA can be used as a chelating agent in the area of dentistry. It does not generate a significant demineralising effect that modifies the physicochemical properties of dentine, as observed with EDTA.

Objective: This study aimed to assess and compare the healing outcome associated with different aqueous-based calcium hydroxide intracanal medicaments in patients with pulpal necrosis and symptomatic apical periodontitis.

Methods: Seventy five patients with pulpal necrosis and symptomatic apical periodontitis in permanent mandibular molar teeth were selected as the part of this study. The participants were randomly allocated to three groups, each comprising 25 patients, based on the type of intracanal medicament used during the treatment procedure. Group 1 consisted of calcium hydroxide (CH) mixed with 0.9% saline (NS), Group 2 contained CH combined with 2% lidocaine, and Group 3 included CH with 2% chlorhexidine (CHX). The Periapical Index Score was utilized to assess the healing of periapical lesions in preoperative and post-operative periapical radiographs at 3 month intervals for 12 months. The Kruskal-Wallis test was used to determine the significance, with Post Hoc Dunn tests for multiple comparisons.

Results: At the 12-month follow-up, the CH+CHX group demonstrated significantly improved periapical healing, with a mean PAI score of 1.57 +- 0.66, compared to CH+LA (2.27+-0.63) and CH+NS (2.48+-0.79), with Kruskal-Wallis p<0.05. The mean time to achieve a healthy periapical status (PAI ≤2) was shortest in the CH+CHX group (8.10+-3.28 months), followed by CH+NS (8.23+-3.28 months) and CH+LA (8.25+-3.31 months), with the multivariate Log-Rank test indicating a statistically significant difference among the groups (p<0.05).

Conclusion: The findings of this study indicate that CH when combined with 2% CHX as an aqueous vehicle demonstrated superior healing of periapical lesions in patients with pulpal necrosis and symptomatic apical periodontitis compared to saline or lidocaine.

Objective: This retrospective study aimed to compare the survival outcomes between crowns with repaired endodontic access cavities and intact crowns and to identify factors that influence restoration longevity.

Methods: Clinical records of patients who underwent root canal treatment through existing crowns (crowns with repaired access cavities, CRA) or received crowns after root canal treatment (intact crowns, IC) between 2012 and 2023 were analysed. A 1: 1 propensity score matching was applied based on age, sex, tooth type, and crown type. The outcomes of the matched cases were classified as survival or non-survival. Kaplan-Meier analysis and logrank tests were used to compare outcomes between the two groups over time. For CRA, multivariable Cox proportional hazards regression analysis was conducted to identify potential predisposing factors.

Results: Among 608 eligible endodontically treated teeth, 120 CRA and 488 IC met the inclusion criteria. After matching, 120 samples per group were analysed. The survival rate was significantly lower for CRA (85.8%) than for IC (91.7%) (p=0.004). Occlusal parafunctional habits or interferences were the only significant factors affecting CRA survival.

Conclusion: CRA demonstrated lower survival rates than IC, with occlusal parafunctional habits or interferences as key factors influencing their longevity.