Search Results (1,173)

Background and Objectives: Premature loss of primary teeth can disrupt occlusal development and oral function. Although iodoform-based materials such as Vitapex^® are widely used, concerns remain regarding their cytotoxicity and potential to accelerate root resorption. Sodium iodide (NaI) has emerged as a biocompatible, antibacterial alternative. This study evaluated the feasibility of a NaI-based root canal filling material in a canine model of Enterococcus faecalis-induced periapical inflammation. Methods: Periapical lesions were induced in a healthy male mongrel dog using E. faecalis (10⁶ CFU/mL). After six weeks, the root canals were obturated with NaI paste, Vitapex^®, or Calcipex. Untreated teeth and an E. faecalis-only group served as controls. Radiographic lesion sizes were monitored at 4, 8, 12, and 16 weeks post-obturation. Histological analysis at 16 weeks assessed inflammatory area and perimeter, stromal fibrosis, inflammatory cell infiltration, and myeloperoxidase (MPO) expression. Results: Radiographically, all treatment groups showed reduced lesion size relative to the positive control. No significant differences were observed among the NaI, Vitapex^®, and Calcipex groups at 4 and 8 weeks; however, significant differences emerged at 12 and 16 weeks (p < 0.05). The NaI group showed lesion reduction until week 8, followed by subsequent expansion thereafter, whereas the Vitapex^® and Calcipex groups showed continuous lesion reduction over time. Histologically, the periapical inflammatory area increased in the order of Vitapex^® < Calcipex < NaI < positive control (p < 0.05). MPO staining identified neutrophils as the primary inflammatory cells. Conclusions: NaI paste showed favorable early radiographic healing but limited long-term stability compared with conventional materials. With further optimization, it may have potential as an alternative root canal filling material. However, given the single-animal exploratory design, these findings should be interpreted as preliminary rather than definitive evidence. Full article

Urban micro-tidal canals frequently suffer from severe hypoxia due to restricted hydrodynamic exchange and untreated discharges. Field monitoring during a 2022 mass fish mortality event at the Dongsam tidal canal revealed that during the ‘tidal window gap’—a hydraulic stagnation period required for passive tidal flushing—bottom-layer dissolved oxygen (DO) plummeted to a lethal 0.44 mg/L. To address the limitations of passive tidal exchange, this study proposes a conceptual hybrid water purification framework integrating active ecological interventions: wall-mounted spiral flow aeration for continuous oxygenation and vertical bio-curtains for pollutant interception. By synergizing fluid mechanics with ecological engineering, core design parameters were systematically derived: an effective mixing width (W_eff = 2.2 h), longitudinal spacing (L_s = 13.6 × W_eff ), an optimal root immersion ratio (D_r/h = 0.6), and climate-adaptive planting densities (ρ_p ≈ 2–32 plants/m²). Additionally, a corrosion-resistant FRP guide rail system was incorporated to facilitate autonomous adaptation to tidal fluctuations. The framework was conceptualized through a prototype design for the Dongsam canal and subsequently scaled to 15 international micro-tidal canals across diverse climatic zones. The optimized bilateral staggered configuration established a continuous 528 m² ecological refuge, ensuring DO levels recover above the critical 3 mg/L threshold. Ultimately, this research presents a comprehensive methodological framework and a flexible engineering toolkit to guide water quality and ecological resilience enhancements in shallow urban waterways worldwide. Full article

The purpose of this investigation was to establish a clinical diagnosis of the cause of instrument fracture and to evaluate its impact on fragment removal success. One hundred cases of fractured endodontic instruments were analyzed to determine the relationship between fracture cause (flexion, torsion, or combined) and removal outcomes. A diagnostic protocol was developed to classify the fracture mechanism based on radiographic findings, clinical observations, and instrument-related parameters. Fragment length, intracanal location, and removal time were recorded. Torsion was the most frequent cause (54%), followed by combined fracture (33%) and flexion (13%). Flexion-related fragments were significantly longer, located in more accessible areas, and exhibited lower mechanical retention, resulting in shorter removal times (mean: 19.62 min). In contrast, torsion-related fragments were shorter, showed greater retention, and required longer removal times (mean: 32.98 min). Statistical analysis demonstrated a significant association between fracture cause, fragment location, and removal time. The fracture mechanism may serve as a predictive clinical factor for fragment removal difficulty. Early identification of this parameter can improve treatment planning and optimize clinical resource management. Full article

Introduction: Advancements in thermo-mechanical surface treatment of endodontic nickel–titanium (NiTi) instruments introduced another aspect of variation. Particularly related to their metallurgy, which influences their behaviour in relation to temperature. This is clinically significant, considering the variation in the temperatures inside the root canal during instrumentation. This study aimed to compare the effects of different temperatures on the bending stiffness, cyclic fatigue resistance, and cutting efficiency of two reciprocating heat-treated NiTi files: R-Motion (RM) and WaveOne Gold (WOG). Methodology: Bending stiffness was examined in a temperature-controlled water bath, measuring the maximum force in Newtons during a 3 mm tip horizontal displacement. The cyclic fatigue resistance was tested in a simulated stainless-steel canal (35° curvature, 6 mm radius) in dynamic mode at 22 °C, 37 °C, and 45 °C. Time to fracture (TTF) and length of fractured fragment were recorded, and representative samples were examined using scanning electron microscopy. The cutting efficiency was assessed using bovine bone slabs measuring 1.5 mm in thickness and 15 mm in width. The files were activated in reciprocation mode for three minutes while resting on the upper surface of the slab, while submerged in a water bath maintained at 22 °C, 37 °C, or 45 °C. The maximum cutting depth was measured in millimetres under magnification. Additionally, Differential Scanning Calorimetry (DSC) analysis was performed for three specimens of each file type. Results: RM exhibited significantly higher TTF, longer fractured fragments, and smaller cutting depths than WOG across all temperatures. The RM was significantly stiffer at 37 °C and 45 °C only. For each file type, increasing the temperature was associated with a significant increase in stiffness (p < 0.01), except for WOG between 22 °C and 37 °C (p = 0.199). The TTF was significantly higher in RM at 22 °C, while the TTF in WOG increased significantly with lower temperatures. No effect was observed on the length of the fractured fragment. Lower temperatures were also associated with reduced cutting efficiency in both files. Conclusions: Temperature has a significant impact on the properties and performance of RM and WOG and should be considered during instrumentation. File design has a greater influence on their strength and cutting ability than their transformation behaviour related to heat treatment. Full article

Calcium silicate-based sealers are widely used in contemporary endodontics, but their strong interaction with dentinal substrates may complicate their removal during nonsurgical retreatment and potentially hinder canal disinfection. This ex vivo study evaluated the effectiveness of different irrigation activation techniques in removing a calcium silicate-based sealer from oval-shaped root canals. Sixty extracted single-rooted teeth were instrumented and obturated using the single-cone technique with NeoSealer Flo, followed by retreatment using a reciprocating system. Specimens were randomly assigned to four final irrigation protocols: conventional needle irrigation (CNI) with NaOCl/EDTA, ultrasonic activation (US), diode laser activation (LI), and Er:YAG laser activation using the SWEEPS mode (SW) (n = 15). Residual filling material was quantified before and after final irrigation using stereomicroscopic imaging and ImageJ (version 1.54) analysis. Dentinal surface morphology and residual sealer were further evaluated using SEM–EDS. Statistical analysis included one-way ANOVA and chi-square tests (p < 0.05). All protocols significantly reduced residual filling material compared with mechanical retreatment alone (US 15.08%, CNI 7.89%, LI 8.01%, SW 7.20%) (p < 0.01). US resulted in significantly greater sealer removal compared with CNI, LI, and SW, with mean differences ranging from 7.08% to 7.88% (p < 0.05). These findings indicate that irrigation activation enhances the removal of NeoSealer Flo calcium silicate-based sealer, with ultrasonic activation demonstrating greater effectiveness among the evaluated techniques, under the conditions of this experimental setup. Full article

In the oral environment, silicone (polysiloxane) supports healing by creating low-permeability interfaces that limit microleakage, whereas silicon/silica systems support healing via hydroxyapatite nucleation. We synthesized human evidence on intraoral healing associated with silicone and silicon/silica-based materials and assessed translational differences between preclinical models and clinical settings. A systematic review (1990-September 2025) identified 14 clinical studies of bioactive glass (BAG) that met the inclusion criteria. Periodontal outcomes included probing depth (PD), clinical attachment level (CAL), and radiographic fill; endodontic outcomes included the periapical index (PAI). Human BAG studies showed periodontal benefits versus controls in intrabony defects, with reduced PD, improved CAL, and greater radiographic fill. For endodontic healing, a multicenter randomized clinical trial reported improved PAI at 12 months in both the zinc-oxide-eugenol and silicone-sealer groups without a significant between-group difference. The literature supports a functional split: silicone primarily provides sealing and permissive healing, whereas silicon/silica-based materials support signaling, interfacial bonding, and regenerative healing. Clinically, BAG appears most relevant for contained periodontal intrabony defects, whereas silicone sealers should be viewed primarily as stable sealing adjuncts to well-executed root canal therapy. Full article

Objectives: To evaluate the physicochemical properties of a novel strontium silicate-based root canal sealer (C-Root SP) in comparison with a calcium silicate-based sealer (TotalFill BC) and an epoxy resin-based sealer (AH Plus). Methods: Setting time, net mass change (apparent solubility behavior), pH changes, and surface characteristics were assessed based on ISO 6876 and ANSI/ADA Specification No. 57, with minor methodological modifications. Net mass change and pH were evaluated over 28 days. Surface morphology and elemental composition were analyzed after dry and aqueous aging in deionized water using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Data were analyzed using one-way and repeated-measures ANOVA with Tukey’s post hoc test (α = 0.05). Results: AH Plus exhibited the longest initial and final setting times (10.93 ± 0.65 h and 37.33 ± 0.13 h), whereas TotalFill BC showed the shortest (7.98 ± 0.32 h and 30.18 ± 0.20 h); C-Root SP demonstrated intermediate values (9.35 ± 0.38 h and 32.75 ± 0.57 h) (p < 0.001). C-Root SP exhibited positive net mass change values (indicative of net mass loss), ranging from 5.32 ± 4.72% at 24 h to 6.83 ± 5.55% at 28 days, significantly higher than AH Plus and TotalFill BC (p < 0.001), which showed negative values indicative of apparent mass gain. All sealers demonstrated alkaline conditions, with C-Root SP maintaining the highest apparent pH values throughout the evaluation period (p < 0.001). Surface and compositional changes were observed in the bioceramic sealers following aqueous aging, with increased detectable strontium content in C-Root SP. Conclusions: C-Root SP exhibited physicochemical behavior consistent with a strontium-modified calcium silicate-based sealer, characterized by hydration-driven hydroxyl ion release resulting in apparent alkalinity and ion exchange-associated behavior, and dynamic surface changes consistent with those reported for bioceramic materials. Clinical Significance: Strontium incorporation may influence hydration-mediated physicochemical behavior; however, further in vitro and in vivo studies are required to determine its clinical relevance. Full article

Root canal sealers play a crucial role in the success of endodontic treatment, facilitating healing and regeneration of the periapical region. This study aimed to evaluate the biological, physicochemical and structural properties of two sealers, AH Plus and ROEKO GuttaFlow 2. Scanning electron microscopy (SEM) analysis reveals polyhedral particles uniformly distributed within the porous organic matrix of AH Plus, whereas ROEKO GuttaFlow 2 exhibits a heterogeneous structure, with particles distributed evenly. Fourier-Transform Infrared Spectroscopy (FT-IR) analysis confirmed the characteristic chemical bonds associated with both the organic and inorganic phases of each material, while X-Ray diffraction analysis identified the main crystalline phases (CaWO₄ and ZrO₂ for AH Plus and ZrSiO₄ and ZrO₂ for ROEKO GuttaFlow 2). The biocompatibility tests were performed on human osteosarcoma cells (ATCC—G 292 CRL-1423). An in vitro metabolic activity and viability test (MTT) showed a significant decrease by ~92% (* p < 0.05) and ~87% after 24 and 48 h for samples incubated with AH Plus versus the control. Regarding ROEKO GuttaFlow 2, MTT levels increased by ~8% in the first 24 h, while after 48 h they decreased by ~11% versus control. Lactate dehydrogenase levels significantly increased at 24 and 48 h for cells incubated with AH Plus (*** p < 0.001, ** p < 0.01). ROEKO GuttaFlow 2 significantly decreased the LDH level at 24 h (** p < 0.01), while at 48 h a rise was observed. The significantly increased levels of nitric oxide observed in cells incubated with the materials at 24 and 48 h (** p < 0.01, *** p < 0.001) suggest a cellular adaptation to our experimental environment. Overall, ROEKO GuttaFlow 2 exhibited a more favorable profile under our testing conditions. Full article

Objectives: To quantitatively evaluate the inhibitory effects of commercially available probiotic formulations (Probien, Enterogermina, Reflor) applied as intracanal medicaments against mature dual-species biofilms of Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) using a qPCR-based in vitro root canal model, with calcium hydroxide included as the reference intracanal medicament for comparison. Materials and Methods: Root canal specimens containing mature dual-species biofilms were medicated with probiotic–poloxamer gel formulations (Probien, Enterogermina, or Reflor) or calcium hydroxide (reference inhibitory control); infected but untreated canals served as the non-inhibitory control, and sterile non-inoculated specimens were included to confirm procedural sterility. After a 7-day intracanal application period, microbial loads were quantified at baseline and post-treatment by qPCR, and results were expressed as delta cycle threshold (ΔCt), colony-forming equivalents (CFE/mL), and percentage reduction values. Results: A total of 78 specimens (n = 13 per group) were analyzed. No significant intergroup differences were found in E. faecalis ΔCt or reduction percentages (p > 0.05), indicating its persistence despite intracanal medication. For C. albicans, differences among groups were significant (p < 0.001). Calcium hydroxide showed the strongest antifungal effect, producing marked ΔCt and CFE reductions versus probiotic and positive control groups, whereas probiotic formulations displayed only limited antifungal activity and no measurable inhibition against E. faecalis. Conclusions: Under the conditions of this in vitro model, the tested commercially available probiotic formulations—originally developed for gastrointestinal use—did not demonstrate significant antimicrobial effects against mature E. faecalis–C. albicans biofilms. These findings should be interpreted in the context of the absence of probiotic formulations specifically designed for intracanal use and the distinct ecological characteristics of the root canal system, which represents a closed, low-oxygen environment dominated by hard-tissue surfaces. Rather than excluding the potential of probiotics in endodontics, the present results highlight the need for root canal–adapted probiotic strains and delivery strategies tailored to intracanal conditions. Clinical Relevance: This in vitro study provides experimental insight into the limitations of directly applying commercially available gastrointestinal probiotic formulations within the root canal system. The findings highlight the importance of developing root canal–specific probiotic strains and delivery strategies tailored to the unique ecological conditions of the intracanal environment, thereby informing future translational and experimental research in biological endodontics. Full article

Background: Successful healing of chronic apical periodontitis after endodontic treatment requires a reduction in the size of the radiolucent area and the healing of the bone. This study aimed to compare the effects of different irrigation activation techniques on healing in single-rooted mandibular premolar teeth with periapical lesions of endodontic origin. Methods: A total of 132 systemically healthy patients with mandibular single-rooted premolar teeth and a periapical index (PAI) score ≥ 3 were assigned to five experimental groups (Sonic activation, Passive ultrasonic irrigation, Photon-Induced Photoacoustic Streaming, Shock Wave Enhanced Emission Photoacoustic Streaming and Manual dynamic activation) and a control group (Conventional Syringe Irrigation). After access cavity preparation, the canals were prepared up to three sizes larger than the initial apical diameter with 5 mL of 2.5% NaOCl used between each file. Final irrigation was performed via the assigned activation system. The root canals were obturated with gutta-percha in a single visit. The effects of the activation systems on healing were compared at 1-year follow-up. The primary outcome measure was the change in lesion diameter. PAI score and fractal dimension (FD) were evaluated as secondary outcomes. Results: At the 1-year follow-up, FD values significantly increased, PAI scores and lesion size decreased in all groups compared with baseline (p < 0.001). However, the increase in FD was comparable among the irrigation groups (p > 0.05). In contrast, lesion size reduction and PAI-based healing rates favored the laser-activated groups. The PAI scores and lesion size in the control group were significantly greater than that in the laser groups (p < 0.05). Conclusions: At the 1-year follow-up, all the groups presented similar FD increases, while the laser irrigation groups presented significantly greater reductions in lesion size than did the control group. Full article

Background: Guided endodontics (GE), introduced in 2016, is an innovative approach aimed at addressing the challenges faced in endodontic treatment, particularly in cases of pulp canal obliteration (PCO). Objectives: This narrative review aims to assess the efficacy and application of static guided endodontics to facilitate minimally invasive access to difficult-to-locate root canals during primary endodontic treatment of incisors and canines. Method: A search strategy of the literature was performed on PubMed until 18 November 2025. The review synthesizes findings from 28 studies, focusing on recent advancements, procedural planning, and clinical outcomes related to GE. Results: Key findings indicate that GE may improve the ability to locate and treat calcified canals, reduce complications associated with traditional methods. Radiographic assessments and clinical indicators demonstrate favorable short- to medium-term outcomes; however, there is an absence of standardized protocols for long-term follow-up. Conclusions: Recommendations for future research include the establishment of unified technical guidelines to enhance consistency and comparability of results across clinical settings. Overall, guided endodontics represents a promising advancement in improving the success of root canal therapy while preserving natural dentition. The primary goal of this article is to update the literature review on static guided endodontics in anterior teeth during primary endodontics. Full article

Background: Persistent endodontic infections involving Enterococcus faecalis and Candida albicans are a major cause of root canal treatment failure. Although conventional irrigants, such as sodium hypochlorite and chlorhexidine (CHX), exhibit strong immediate antimicrobial activity, microbes may survive and recover from the initial antimicrobial effect, hence limiting their effectiveness, especially in complex root canal anatomies and in the apical terminus of the tooth. Antibacterial dressing techniques were not proven satisfactory due to depletion of the antibacterial component or difficulty in spreading it evenly along the entire root canal. This study aimed to develop and evaluate the antimicrobial efficacy and release characteristics of a novel sustained-release device (SRD), delivering CHX via gutta-percha points coated with a sustained-release formulation used as a temporary intracanal medicament. Methods: Gutta-percha points were coated with two sustained-release CHX varnishes (CHX1 and CHX2) or a placebo and assessed in vitro. Antimicrobial activity against E. faecalis and C. albicans was evaluated using agar diffusion assays over time. Release kinetics were analyzed using Rhodamine-labeled SRD in a 3D-printed acrylic molar tooth model via fluorescence microscopy. Additionally, biofilm-infected acrylic molar teeth were treated with a placebo, a single 2% CHX irrigation, or SRD-coated gutta-percha points placed as an intracanal dressing prior to obturation. Microbial viability was quantified by colony-forming unit (CFU/mL) analysis from root canals and gutta-percha points. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post hoc multiple comparison test (p < 0.05). Results: SRD-coated gutta-percha points demonstrated sustained antimicrobial activity for up to 21 days against E. faecalis and 19 days against C. albicans. Fluorescence analysis, in an acrylic tooth model, confirmed continuous release for up to 15 days, with pronounced diffusion in the isthmus and palatal canals. In biofilm-infected acrylic teeth models, SRD treatment resulted in a significant reduction of 2–3 log₁₀ CFU/mL compared to placebo groups (p < 0.001) and prevented microbial rebound over the 14-day observation period. In contrast, a single application of 2% CHX solution showed only transient reduction followed by regrowth. Conclusions: Sustained-release CHX delivery via polymer-coated gutta-percha points provided prolonged antimicrobial activity against bacterial and fungal biofilms compared to conventional single-dose CHX application in this in vitro model. These findings support the potential use of coated gutta-percha points as a removable intracanal drug delivery platform prior to final obturation, although further studies incorporating direct-release quantification and in vivo validation are required before clinical translation. Full article

Objectives: The identification of novel antimicrobial agents for use in root canal treatment may provide opportunities to improve treatment outcomes. This study aimed to assess the antimicrobial efficacy of different molecular weights of chitosan (CS), and how modification with CS may impact on the antimicrobial, physico-mechanical and biological properties of Biodentine™, a calcium-silicate-based material used in endodontics. Methods: C. albicans biofilms were treated with either 3% sodium hypochlorite (NaOCl) or a 0.05% or 0.1% CS solution for 5 min. The growth medium was replenished, and cells were re-incubated for additional 72 h. Regrowth of biofilms was assessed using a colorimetric XTT assay. Additionally, multispecies biofilms were established and the regrowth of biofilms on Biodentine discs were quantified following the addition of 0.5 wt% and 1 wt% of CS powder using qPCR. The physico-mechanical and biological properties of the new composite of Biodentine and CS were also evaluated. Results: Viability readings revealed significant initial biofilm inhibitory effects of CS solutions, followed by significant regrowth after 72 h. Upon the addition of CS to Biodentine, significant reductions in multispecies biofilm regrowth were determined. Notably, the antibiofilm activity of CS was found to be increased as the molecular weight decreased. The addition of powdered CS of low molecular weight showed a reduction in the mechanical properties of Biodentine, whereas no detrimental effects on the other material properties were noted. Conclusions: Chitosan may not be useful as an alternative irrigant to NaOCl. Addition of CS to Biodentine represents a potential means of augmenting the antimicrobial activity of Biodentine against persistent microorganisms following endodontic therapy. Despite the reductions in mechanical properties of the material, the new composite still represents a viable material option when material strength and hardness are not critical. Full article

Background/Objectives: Half of diagnosed unilateral maxillary sinusitis may have odontogenic origin, and root canal treatment (RCT) can be beneficial as a single-mode treatment for full resolution of maxillary sinusitis of endodontic origin (MSEO) symptoms. The aim of the study was to investigate the influence of passive ultrasonic irrigation (PUI) on the healing of MSEO after non-surgical endodontic treatment. Methods: A single-center, retrospective study was conducted on CBCT data and medical records of 240 patients, who underwent non-surgical endodontic treatment, performed by the same operator between 2016 and 2025. One hundred and thirty-six teeth entered the study due to inclusion/exclusion criteria. Results: Complete healing was observed in 75.74% of the cases (n = 103). The tooth most frequently associated with MSEO was the first upper molar (52.21%, n = 71). PUI was applied in 66.91% of the treatments (n = 91). PUI was an independent predictor of MSEO healing (p = 0.001; 95% CI [1.768; 9.136]). When PUI was introduced in RCT, complete healing of MSEO was observed in 84.62% of the cases (n = 77). PUI was independently associated with higher odds of radiological resolution of MSEO in univariate logistic regression (OR = 4.019) and multiple logistic regression (OR = 12.388) models. Conclusions: PUI application in the irrigation protocol was associated with higher rates of MSEO healing after non-surgical endodontic treatment (p = 0.001; 95% CI [1.768; 9.136]). The rate of MSEO healing after non-surgical RCT is high (75.74%); therefore it should be considered as a single-mode treatment option in cases of unilateral maxillary sinusitis. Full article

Background/Objectives: This study aims to compare two techniques for the removal of Thermafil obturators, evaluating the influence of operator experience in two different typologies of samples. Methods: Sixty single-rooted extracted teeth with round canals and sixty 3D-printed teeth reproducing a maxillary central incisor were obturated with Thermafil obturators. Retreatment was undertaken under a dental operating microscope by an experienced endodontist and a novice operator using either the braiding technique or Reciproc. The removal time was recorded. Results: Considering natural teeth, seven failures were registered, and 60 carriers were removed successfully (90%). Removal time was significantly shorter for the experienced operator than for the novice (Braiding technique: p < 0.001; Reciproc: p = 0.001). No statistically significant difference emerged in the expert operator between braiding and reciprocating techniques (p = 0.403), while a longer carrier removal time emerged in the novice operator using the manual instrumentation (p = 0.019). Considering 3D-printed teeth, eight failures were registered, and 60 carriers were removed successfully (88%). There was no significant difference in removal time between novice and experienced operators. Carrier removal time was significantly lower in the braiding technique for the novice compared to the experienced operator (p = 0.017). This difference was not observed for the reciprocating instrumentation (p = 0.244). Regarding experience, in both operators, removal time was shorter with reciprocating instrumentation than with the braiding technique (p < 0.001). Conclusions: The braiding technique and Reciproc are effective in the retreatment of straight, round-section canals filled with Thermafil. Within the limits of this in vitro study, restoration of the working length can be undertaken quickly and with favourable outcomes. Experience significantly affects the removal time of carrier-based obturations. The removal technique did not influence retrieval time in the experienced operator, while the Reciproc proved to be an effective aid for the novice operator. Full article