Search Results (283)

Background: Successful root canal treatment depends on achieving an effective three-dimensional seal and limiting microbial persistence and reinfection. Dentinal tubule penetration may enhance sealing by increasing sealer–dentin contact and micromechanical retention. This study compared the dentinal tubule penetration of BioRoot RCS, NeoSealer Flo, and TotalFill BC Sealer with AH Plus using the calcium-sensitive fluorophore Fluo-3 and evaluated the effect of sonic activation of final irrigation. Methods: 128 extracted human single-rooted teeth were allocated to four sealer groups and subdivided according to final irrigation protocol: non-activated final irrigation (NAFI) or sonic-activated final irrigation (SAFI). Sealers were labeled with 0.1% Fluo-3, and canals were obturated using the single-cone technique. Root sections obtained at 3, 5, and 8 mm from the apex were analyzed by CLSM. Penetration area and depth percentages were calculated and statistically compared (p < 0.05). Results: All sealers penetrated dentinal tubules. For overall penetration, under NAFI, BioRoot RCS and NeoSealer Flo showed significantly greater penetration area than AH Plus and TotalFill BC Sealer, while BioRoot RCS showed significantly greater penetration depth than AH Plus and TotalFill BC Sealer. Under SAFI, BioRoot RCS and NeoSealer Flo showed significantly greater penetration area than TotalFill BC Sealer, whereas NeoSealer Flo showed significantly greater penetration depth than all other sealers (p < 0.05). Sonic activation significantly increased penetration in selected sealers and root thirds; for NeoSealer Flo, penetration depth increased from 37.55% to 49.15% in the coronal third and from 33.10% to 48.73% in the middle third, while AH Plus also showed increased penetration apically and no significant effect was observed for BioRoot RCS. Penetration was generally greatest coronally and lowest apically. Conclusions: Dentinal tubule penetration was influenced by sealer type, final irrigation protocol, and root third. Sonic activation improved penetration under specific conditions but did not produce a uniform effect across all sealers or root thirds. Full article

Background: Nickel–titanium (Ni-Ti) instruments are continuously exposed to irrigating solutions during root canal preparation, which may affect their surface integrity. Evidence regarding the combined morphological and elemental effects of contemporary irrigation protocols on heat-treated single-file systems remains limited. This study evaluated the effects of different irrigation protocols on the surface morphology and elemental composition of Super One File Ni-Ti instruments using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Methods: Thirty Super One File instruments (size 25/.04) were randomly allocated to three groups: distilled water (DW), a sequential NaOCl–EDTA–NaOCl irrigation protocol (NEN), and a NaOCl/HEDP continuous chelation protocol. Instruments were continuously rotated in the assigned solution for 20 min. Surface morphology was assessed by SEM and elemental composition by EDS. SEM data were analysed using the Fisher–Freeman–Halton exact test, whereas EDS data were analysed using linear mixed-effects models with post hoc pairwise comparisons (α = 0.05). Results: SEM analysis revealed protocol- and region-dependent differences in surface alterations. The NEN group showed significantly higher corrosion and pitting frequencies than the DW group in selected regions, whereas no significant differences in these outcomes were detected between the NEN and HEDP groups. EDS analysis showed significant protocol × region interactions for all elements except Cl. These differences were most pronounced in the coronal region, where the HEDP group exhibited lower Ni and Ti and higher O, P, Na, and Ca levels than the DW and NEN groups. Conclusions: The tested irrigation protocols produced distinct, region-dependent surface responses in Super One File instruments, highlighting the potential influence of irrigation chemistry on Ni-Ti instrument surfaces under controlled experimental conditions. The clinical and mechanical implications of these alterations remain to be established. Full article

Background and Objectives: The aim of this study was to evaluate the penetration of laser-activated irrigation solutions into dentinal tubules in root canals with different degrees of curvature and different coronal flaring. Materials and Methods: Seventy-six maxillary first molar teeth previously extracted for various reasons were included in the present study. The specimens were divided into two main groups according to distal root canal curvature, determined using the Schneider method: straight (<10°) and curved (20–40°). These groups were further classified into two subgroups according to whether a coronal flaring procedure was performed (n = 19). Following root canal preparation of all specimens, final irrigation was performed using a laser activation method and an irrigation solution prepared with the fluorescent dye Rhodamine B. Horizontal apical, middle, and coronal sections of 1 ± 0.1 mm thickness were obtained from the specimens at 2 mm, 5 mm, and 8 mm from the apical foramen, respectively. The effect of the irrigation solution on dentinal tubule penetration in the root canals was evaluated in the obtained sections using confocal laser scanning microscopy. Following evaluation, the mean and maximum penetration distances into the dentinal tubules were measured. The obtained data were statistically analyzed using Generalized Estimating Equations and Bonferroni correction for multiple comparisons, with the significance level set at p < 0.05. Results: The analysis revealed that only the region factor had a statistically significant effect on mean penetration values (p < 0.001), whereas canal curvature (p = 0.010), coronal flaring (p = 0.002), and region (p < 0.001) had statistically significant effects on maximum penetration values. However, none of the two-way or three-way interactions were significant (p > 0.05). Conclusions: Coronal flaring did not affect mean dentinal tubule penetration but increased maximum penetration depth. Maximum penetration was higher in straight canals than in curved canals, while both mean and maximum penetration were significantly affected by the root canal region. Full article

This study evaluated and compared four irrigation activation protocols—conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI), photon-induced photoacoustic streaming (PIPS), and shock wave-enhanced emission photoacoustic streaming (SWEEPS)—with 17% EDTA as a final irrigant, with respect to smear layer (SL) removal and push-out bond strength (PBS) of root canal sealer in the apical third of curved root canals. One hundred and twenty extracted single-rooted human premolars with oval canals and moderate curvature (20–40°, Schneider’s method) were allocated into four groups randomly (n = 30 each). Canals were prepared crown-down under 2.5% NaOCl irrigation, followed by final 17% EDTA irrigation per the assigned protocol: CSI, PUI, PIPS, and SWEEPS. 10 specimens per group underwent SEM evaluation of SL removal using Hülsmann’s criteria; remaining specimens were obturated. In 10 samples, apical sealer adaptation was assessed via SEM. PBS of ten samples were evaluated using a universal testing machine, followed by failure mode assessment. Data were statistically evaluated using two-way mixed ANOVA, followed by Tukey’s post hoc test for PBS and Kruskal–Wallis test with Dunn’s multiple-comparison test with Bonferroni correction for SL scores (p < 0.05). Minimum SL removal was exhibited by the apical third of Group 1 (CSI-EDTA) samples. PIPS-EDTA and SWEEPS-EDTA presented comparable SL elimination outcomes in the cervical and middle thirds (p > 0.05). SL elimination between these two groups was significantly different in the apical third. The cervical section of Group 4 displayed the highest bond integrity. However, the lowest bond strength was exhibited by the apical third of Group 1 (CSI-EDTA). SWEEPS combined with EDTA demonstrated superior smear layer removal throughout curved root canals, including the apical third, and yielded the highest push-out bond strength among all tested irrigation protocols. Full article

Background and Objectives: Residual filling material may persist on the walls of oval root canals after mechanical retreatment, and the influence of sodium hypochlorite (NaOCl) concentration and supplementary irrigation procedures on its removal remains unclear. This laboratory study used scanning electron microscopy (SEM) to evaluate the effects of three NaOCl concentrations and five final irrigation protocols on residual filling material in retreated oval canals of mandibular premolars. The protocols tested were conventional needle irrigation (CNI), EDDY, passive ultrasonic irrigation (PUI), XP-endo Finisher R (XPFR), and Shock Wave Enhanced Emission Photoacoustic Streaming (SWEEPS). Materials and Methods: One hundred twenty extracted mandibular premolars with a single root and an oval canal were instrumented with Reciproc R25 and filled with CeraSeal and a matching gutta-percha cone using the single-cone technique. Root canal retreatment was performed using ProTaper Universal Retreatment instruments followed by Reciproc R40. The teeth were then distributed among 15 experimental subgroups according to the final irrigation protocol and NaOCl concentration used: 2.5%, 5.25%, or 8.25% (n = 8). After irrigation, each root was divided longitudinally, and one undamaged canal half was randomly chosen for SEM evaluation. Residual filling material was scored in the coronal, middle, and apical regions using an ordinal scale ranging from 1 to 5. Examiner agreement was determined with quadratically weighted Cohen’s kappa, while treatment effects were examined using a cumulative link mixed model (CLMM). Results: Residual filling material scores differed significantly according to the final irrigation protocol (p < 0.001) and root canal region (p = 0.007), but not according to NaOCl concentration (p = 0.236). The interaction between protocol and canal region was also significant (p = 0.036). In the overall comparisons, CNI produced the highest scores, whereas SWEEPS produced the lowest, and EDDY, PUI, and XPFR did not differ significantly from one another. Apical scores were higher than coronal and middle scores in the EDDY, PUI, and SWEEPS protocols, while XPFR showed no significant variation among canal regions. Conclusions: Residual filling material scores after retreatment were influenced by the final irrigation protocol and root canal region, whereas NaOCl concentration had no significant main effect. SWEEPS resulted in the lowest overall residual filling material scores and CNI in the highest, while EDDY, PUI, and XPFR showed comparable overall performance, although protocol performance varied across root canal regions. Full article

Background/Objective: Root canal debridement is limited by complex anatomy and the apical vapor lock phenomenon, reducing smear layer removal. This study evaluated the effect of a 5 µm zirconia microparticle suspension used with sonic, passive ultrasonic irrigation (PUI), or erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser activation on smear layer removal across the root canal thirds. Methods: Sixty single-rooted human teeth were prepared to size F4 (40/0.06) using 5.25% NaOCl and randomly assigned to six groups (n = 10) combining activation modality (sonic, PUI, or Er,Cr:YSGG laser) and irrigant type (distilled water or 5 µm zirconia suspension) over a 5 min interrupted cycle. Smear layer removal was scored using scanning electron microscopy (SEM) and the Hülsmann grading system. Data were analyzed via Kruskal–Wallis and Friedman tests with post hoc pairwise comparisons (α = 0.05). Results: Inter-rater reliability was strong (Cohen’s κ = 0.736–0.822; p < 0.001). Smear layer removal varied significantly across root thirds (p < 0.001). Ultrasonic + Zirconia demonstrated superior removal in the middle third compared with Sonic + Distilled Water (p = 0.005), and in the coronal third compared with Laser + Distilled Water (p = 0.003) and Sonic + Distilled Water (p = 0.026). Coronally, Ultrasonic + Distilled Water outperformed Laser + Distilled Water (p = 0.041). No significant differences occurred apically (p > 0.05). Conclusions: Incorporating 5 µm zirconia microparticles with passive ultrasonic activation improved smear layer removal, particularly in the coronal and middle thirds of the root canal under the conditions of this ex vivo study. Full article

Background and Objectives: This study compared the antimicrobial effects of chitosan and sodium hypochlorite against Enterococcus faecalis (E. faecalis) at different irrigation solution concentrations. E. faecalis is a persistent pathogen frequently surviving root canal treatment, while sodium hypochlorite remains the current gold-standard irrigation material. Materials and Methods: A systematic review and meta-analysis of in vitro studies was conducted using Cochrane Library, EMBASE, and PubMed. Evidence certainty was assessed with GRADE. Two outcomes were analyzed: colony-forming units (CFU/mL) and the inhibition rate (IR). Two reviewers independently screened studies and extracted data. Results: Of 889 identified records, 10 studies met the inclusion criteria. For CFU/mL, the overall effect was −0.28 (95% CI: −1.54 to 0.97). For IR, chitosan concentrations < 1% showed an effect of –7.35 (95% CI: −27.27 to 12.56), while concentrations ≥ 1% showed an effect of −0.90 (95% CI: −19.24 to 17.45). Conclusions: Chitosan demonstrated antimicrobial activity comparable to sodium hypochlorite in vitro, with concentrations above 1% showing enhanced antibacterial effects. However, methodological heterogeneity limits direct comparison, and clinical equivalence cannot be concluded. Full article

Objective: To report the conservative management of a complex failed apexification in a permanent premolar complicated by severe internal root resorption, irregular apical calcification, and exceptionally thin root canal walls and to evaluate its long-term (56-month) clinical and radiographic outcomes. Methods: A 27-year-old male presented with chronic apical periodontitis in the right mandibular first premolar. A previous apexification attempt had failed, resulting in arrested root development, an apical calcified bridge, and extensive internal root resorption. CBCT imaging revealed a critical root canal wall thickness of less than 1 mm in the middle and coronal thirds. To avoid extraction or invasive surgery, a non-surgical apical barrier technique was performed. Due to the severe structural compromise and high risk of root fracture, mechanical instrumentation was minimized; instead, chemomechanical debridement was optimized using Er:YAG laser-activated irrigation. The apical region was sealed with a bioceramic material (iRoot BP), and the weakened root structure was reinforced intraradicularly with dual-cure flowable resin, followed by progressive occlusal adjustments. Results: At the 3-month follow-up, the patient was completely asymptomatic, and radiographs indicated initial periapical bone healing. The 56-month follow-up demonstrated progressive formation of mineralized tissue, apparent thickening of the root canal walls at root apex, complete resolution of periapical radiolucency, and a stable, functional occlusion. Conclusions: This case demonstrates that teeth with severe structural compromise and internal resorption following failed apexification are not necessarily hopeless. A tailored conservative approach, integrating advanced laser-assisted disinfection, bioceramic apical barriers, internal resin reinforcement, and meticulous occlusal management, can yield highly successful long-term outcomes, ensuring the preservation of the natural dentition. Full article

Background: Continuous chelation with etidronic acid (1-Hydroxyethylidene-1,1-diphosphonic acid, HEDP) has been proposed as a less aggressive alternative to sequential irrigation with ethylenediaminetetraacetic acid (EDTA) in endodontics. This systematic review and meta-analysis aimed to compare the effects of these two protocols on the mechanical properties and structure of root dentin. Methods: PubMed, Scopus, and Cochrane Central databases were searched up to June 2026 for in vitro studies comparing continuous chelation (NaOCl + HEDP mixture) with sequential irrigation (NaOCl and EDTA) on root dentin of permanent teeth. Studies on coronal dentin and those not using NaOCl + HEDP as a mixture were excluded. Risk of bias was assessed using the QUIN tool. Meta-analyses were performed for fracture resistance using a random-effects model. This review was registered in PROSPERO (CRD420250630663). Results: Twenty studies with a total of 572 specimens were included. Six studies had a low risk of bias and thirteen had a medium risk. The qualitative synthesis showed that HEDP generally resulted in similar or lower levels of erosion, microhardness reduction, demineralization, and collagen degradation compared to EDTA. The meta-analysis revealed no significant difference in fracture resistance (5 studies; SMD = 0.28; 95% CI: −0.37 to 0.92; p = 0.40); however, substantial heterogeneity was observed (I² = 66.7%). Conclusions: The evidence was limited by substantial heterogeneity and mainly medium risk of bias. Within the limitations, in vitro evidence suggests that continuous chelation with HEDP is comparable to EDTA in terms of root dentin mechanical properties and composition, supporting its use as a chelating agent in endodontic practice. This research received no external funding. Full article

Bioceramic sealers have gained widespread acceptance in contemporary endodontics due to their favorable biological properties, dimensional stability, and bioactivity. However, their strong adhesion to dentinal walls and penetration into dentinal tubules may complicate removal during endodontic retreatment procedures. Additionally, the obturation technique may influence both the retreatability of root canal filling materials and the bond strength of sealers and resins to radicular dentin. Methods: One hundred extracted human single-rooted teeth were instrumented using the WaveOne Gold system and obturated with a bioceramic sealer using two techniques: single-cone (Group A, n = 50) and warm vertical compaction (Group B, n = 50). After sealer setting, retreatment procedures were performed using ProTaper Universal Retreatment files combined with passive ultrasonic irrigation. Scanning electron microscopy was used to evaluate smear layer removal and dentinal tubule obstruction. Eighty specimens were subsequently re-obturated with a bioceramic sealer and divided into four subgroups according to the obturation technique used before and after retreatment. A push-out bond strength test was performed on coronal, middle, and apical root sections. Statistical analysis was conducted using SPSS software with a significance level set at p ≤ 0.05. Results: No statistically significant differences were observed between the groups regarding the working time required for root filling removal (p > 0.05). However, significant differences were found in push-out bond strength values among the experimental groups (p < 0.05). Specimens obturated using warm vertical compaction showed significantly higher bond strength compared with the single-cone technique. Scanning electron microscopy observations revealed less residual bioceramic sealer on dentinal walls in the warm vertical compaction group. Conclusions: Within the limitations of this in vitro study, the warm vertical compaction technique demonstrated superior bonding performance and resulted in less residual bioceramic sealer after retreatment compared with the single-cone technique. Full article

Background/Objectives: Activated irrigation techniques improve intracanal disinfection, but their impact on the clinical and radiographic healing of apical periodontitis remains unclear. This systematic review and meta-analysis evaluated the efficacy of passive ultrasonic irrigation (PUI) and laser-assisted irrigation (LAI), without adjunctive systemic antibiotics, on periapical healing compared with conventional irrigation in adult patients. Methods: Following PRISMA guidelines and prospective registration in PROSPERO (CRD420261413401), PubMed, Scopus, Embase, and Web of Science were searched up to February 2026. Randomized controlled trials (RCTs) involving adults with apical periodontitis comparing PUI or LAI against conventional syringe irrigation—with a minimum of 6 months follow-up—were included. Risk of bias was assessed using RoB 2, evidence certainty via GRADE, and a random-effects meta-analysis calculated pooled odds ratios (ORs) and 95% confidence intervals (CIs). Results: Of 1115 records identified, five randomized controlled trials involving 451 teeth fulfilled the eligibility criteria and were included in the qualitative synthesis and quantitative meta-analysis. Activated irrigation significantly increased periapical healing probability compared with conventional irrigation (OR = 2.25; 95% CI: 1.29–3.93; p = 0.004), with no statistical heterogeneity (I² = 0%). Subgroup analyses showed significant benefits for both PUI (OR = 1.95; 95% CI: 1.08–3.54) and LAI (OR = 6.77; 95% CI: 1.63–28.12). The overall certainty of evidence was moderate due to risk of bias concerns. Conclusions: Activated irrigation techniques (PUI and LAI) were significantly associated with improved clinical and radiographic healing of apical periodontitis compared with conventional irrigation alone. Enhanced intracanal disinfection contributes to a more predictable resolution of periapical lesions without adjunctive systemic antibiotics. Further high-quality RCTs with standardized protocols and long-term CBCT-based follow-up are required to confirm these findings. Full article

Odontogenic cutaneous sinus tracts represent an uncommon clinical manifestation of chronic dental infection and are frequently misdiagnosed due to the absence of dental symptoms and their resemblance to dermatologic lesions. This case report describes the nonsurgical endodontic management of a cutaneous sinus tract of dental origin in a 13-year-old patient. The patient presented with a persistent extraoral lesion in the mandibular region, initially evaluated by non-dental specialists. Clinical and radiographic examination revealed a necrotic mandibular first molar associated with a periapical radiolucency and intraoral sinus tract. Nonsurgical root canal treatment was performed using chemomechanical debridement with sodium hypochlorite irrigation and calcium hydroxide as an intracanal medicament. Complete obturation was achieved following resolution of intracanal exudation. No surgical intervention of the cutaneous lesion was undertaken. Progressive healing of the periapical lesion and spontaneous resolution of the extraoral sinus tract were observed over a 6-month follow-up period. This case is noteworthy because it combines a prolonged diagnostic delay, an atypical extraoral manifestation in a child, and successful resolution by nonsurgical endodontic therapy alone without surgical excision of the cutaneous lesion. The 6-month follow-up confirms sustained clinical and radiographic healing, underscoring the importance of early recognition and conservative management in pediatric patients. Early identification and elimination of the dental source can prevent unnecessary surgical procedures and minimize the risk of permanent scarring. Full article

The aim of this systematic review was to assess the influence of different final irrigation protocols and activation methods on the dentinal tubular penetration of calcium silicate-based sealers (CSSs). The review followed the PRISMA 2020 guidelines, and the protocol was registered in the Open Science Framework (OSF; DOI: 10.17605/OSF.IO/5HTVN). A PICOS-based research question was formulated, and a comprehensive literature search was conducted in MEDLINE, Scopus, Embase, Web of Science, and SciELO up to October 2025. After study selection, a qualitative synthesis of methodologies and outcomes was performed, and methodological quality was assessed using the QUIN tool. Twenty-one in vitro studies were included, all of which used single-rooted teeth or single roots. The available evidence suggests that final irrigation protocols may influence CSS penetration, although the magnitude and consistency of this effect varied substantially across studies. Sodium hypochlorite (NaOCl) and 17% EDTA were the most frequently investigated irrigants and were generally associated with improved penetration, but no irrigation protocol or activation technique can currently be considered superior. Current research trends include the evaluation of chelating agents, continuous chelation protocols, and irrigant activation systems such as passive ultrasonic irrigation, sonic activation, laser activation, and XP-Endo Finisher. Future studies should standardize irrigation protocols, activation methods, sealer types, obturation techniques, microscopy-based assessment procedures, and penetration outcome measures, while also including larger samples and more anatomically complex root canal systems. Full article

Background/Objectives: The aim of this study was to compare the effectiveness of the Reciproc Blue (RB) and MicroMega Remover (MR) systems in removing root canal filling material and to evaluate the effect of passive ultrasonic irrigation (PUI) on remaining filling material (RFM) using micro-computed tomography (micro-CT)-based three-dimensional (3D) analysis. Methods: Forty single-rooted mandibular premolar teeth were included in the study. The root canals were prepared up to size F2 using the ProTaper Gold rotary file system and obturated with the lateral compaction technique. After the initial micro-CT scan, the teeth were randomly divided into four groups: Group RB, Group MR, Group RB + PUI, and Group MR + PUI (n = 10). Following retreatment, a second micro-CT scan was performed. The percentage of RFM was calculated, and statistical analyses were performed using Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction. A rank-based factorial analysis was additionally performed (p < 0.05). Results: RFM was observed in all groups. No significant difference was found between the RB (7.37%) and MR (7.31%) systems (p > 0.05). However, the groups treated with PUI (RB + PUI and MR + PUI) showed significantly lower RFM values than the groups without PUI (p = 0.001). Factorial analysis revealed no significant effect of file system or file system × PUI interaction, whereas PUI significantly reduced RFM (p < 0.001). Conclusions: The RB and MR systems demonstrated similar effectiveness in removing root canal filling material. Although complete canal cleanliness could not be achieved, under the in vitro conditions of the present study, PUI significantly reduced the amount of micro-CT-measured RFM. Full article

Under the dual constraints of global food security and ecological protection, conventional agriculture is hampered by low resource efficiency and sluggish environmental response. Crop digital twin technology establishes a dynamic virtual reality system that integrates crops, environment, and water to enable real-time interaction and optimization. Based on the existing literature, this paper reviews the concept, architecture, and core modules of this technology and summarizes its applications in precision irrigation and crop monitoring. There are three major bottlenecks that persist, including limited high-frequency multi-source sensing and spatiotemporal fusion, insufficient parameter calibration and dynamic updating, and weak cross-scale integration from plant to watershed. Water is increasingly recognized as the key constraint and control variable and acting as both the central physiological driver of crop growth and the mass-flow link that connects the soil–plant–atmosphere continuum. The spatiotemporal dynamics of crop water deficit, compensatory root water uptake, evapotranspiration feedback, and the hydraulic behavior of irrigation-district canal systems constitute the core hydrological processes that must be simulated within the digital twin. Synchronizing crop water demand, soil moisture dynamics, atmospheric evapotranspiration, and irrigation scheduling within a unified spatiotemporal framework establishes a complete sensing, diagnosis, prediction and regulation technical chain. This chain offers a core pathway for alleviating agricultural water scarcity, improving irrigation efficiency, and ensuring food security. Full article