Search Results (2,861)

This study comparatively evaluated the influence of processing routes on the optical stability of three dental resin composites: a light-cured direct composite—G-ænial A’CHORD (LCC), a CAD-CAM milled composite—BreCAM.HIPC (MC), and a 3D-printed composite—Saremco Print Crowntec (PC). Specimens were analyzed before (T0) and after hydrothermal aging for 5000 (T1), 10,000 (T2), and 30,000 cycles (T3). Optical stability was assessed through the change in color (ΔE₀₀) and translucency parameter (TP) after aging and immersion in beverages. Surface topography was evaluated using atomic force microscopy (AFM), while Raman spectroscopy was employed to detect aging-induced molecular changes. After aging and staining, all composites exceeded the acceptability threshold for color change. ΔE₀₀ values of 6.8 ± 1.1 (PC), 4.6 ± 0.9 (MC), and 2.1 ± 0.9 (LCC), obtained after initial aging, further increased following prolonged immersion in coffee. After 1 day of immersion in Coca-Cola, MC exhibited the highest ΔE₀₀ values, which slightly exceeded the clinically acceptable threshold. Prolonged immersion (7 days) significantly increased staining for all materials. TP values significantly differed among materials, with the highest values detected for LCC (20.6 ± 3.6) and PC (19.1 ± 1.5) and the lowest values detected for MC (4.9 ± 0.8). Overall, the results demonstrated that ΔE₀₀ was strongly influenced by the processing route and surface topography, whereas changes in translucency parameter (TP) were predominantly governed by the intrinsic properties of the resin composites. Full article

This study evaluated the effects of four cavity disinfection protocols on microtensile bond strength (µTBS) and failure mode of dentin bonded with a universal adhesive in self-etch mode. Sixty human third molars were assigned to five groups (n = 12): Control (Clearfil S3 Bond Universal), Clearfil SE Protect Bond (CPB, MDPB-containing), 2% chlorhexidine (CHX), 5.25% sodium hypochlorite (NaOCl), and 200 ppm hypochlorous acid (HOCl). After disinfectant application and bonding, composite build-ups were sectioned into beams (≈0.9 mm²) and tested as immediate (24 h) and thermocycled (10,000 cycles) subgroups. Data were analyzed using two-way ANOVA, Tukey HSD, and chi-square/Fisher’s exact tests (α = 0.05). At 24 h, NaOCl and CHX produced significantly lower µTBS than the control, HOCl, and CPB groups (p < 0.05). After thermocycling, Control, CPB, and NaOCl declined significantly, while CHX remained stable (p = 0.960) and HOCl showed non-significant reduction (p = 0.086). NaOCl yielded the highest adhesive failure rate and lowest bond strength. CHX reduced initial µTBS but maintained stability. HOCl and CPB produced values comparable to controls, though HOCl was more aging-susceptible. MDPB-containing adhesives may preserve bond durability while providing disinfection. Full article

Background: Wolfram syndrome (WFS) is a rare neurodegenerative disease that is genetically determined and inherited in an autosomal recessive manner. Although the first clinical symptom appearing in early childhood is diabetes mellitus, subsequent symptoms are associated with optic nerve atrophy, followed by central nervous system atrophy. Methods: The aim of the study was to analyse magnetic resonance images (MRI) of the brain in combination with single-voxel magnetic resonance spectroscopy (MRS) and to assess the copy number of mitochondrial DNA (mtDNA-CN) in 10 patients with WFS compared with a control group of 17 healthy individuals. Results: A significant decrease in the amount of selected metabolites was observed in WFS patients compared to controls in all assessed brain regions (pons, cerebellum, white matter, thalamus, and hippocampus). For three metabolites, Glutamate (Glu), Glutamate + Glutamine (Glx) and total N-acetylaspartate (TNAA), significant differences in concentrations were found between the study groups in almost all matrices evaluating specific areas of the brain (p < 0.011), with the exception of a trend toward reduced TNAA in the hippocampus (p = 0.065). In addition, patients with WFS had a significant decrease in the mitochondrial-to-nuclear DNA ratio compared to controls (p < 0.0003). Some metabolites, such as N-acetylaspartate and total N-acetylaspartate, showed strong correlations with specific regions of the visual pathway on MRI scans in patients with WFS. Conclusions: Selected brain metabolites and mtDNA-CN may become potential markers of WFS, and the results of this study may be used to define indicators for future therapeutic strategies. Full article

Objective: To report a rare case of pulp space tissue growth in a mature mandibular molar with severe endo-periodontal involvement after conservative endodontic treatment and to discuss the possible biological explanations, including regeneration and granulation tissue healing. Severe endo-periodontal lesions are challenging, particularly as endodontic regeneration is usually observed in immature teeth, while revascularization in mature teeth, especially in cases of advanced periodontal disease, is rare, as demonstrated in this case. Methods: This study reports a rare case of tissue regeneration versus granulation tissue healing in the pulp space, occurring alongside periodontal healing, in a mature mandibular molar with necrotic pulp and severe periodontal involvement. A 52-year-old patient presented with a mature mandibular molar (tooth #19) exhibiting necrotic pulp with severe endo-periodontal involvement, including grade-3 mobility, tenderness to percussion, a 12 mm probing depth, and extensive periradicular radiolucency. The tooth was diagnosed with necrotic pulp and symptomatic apical periodontitis and was deemed hopeless, with extraction planned. Results: Following patient refusal, endodontic treatment was initiated, including cleaning, shaping, and placement of the intracanal medicament, Ledermix. The patient canceled the extraction due to symptom resolution and disappeared for 12 months. On return, the patient presented with spontaneous pain exacerbated by thermal stimuli, consistent with symptoms of irreversible pulpitis. Clinical examination revealed significant clinical and radiographic improvements, including reduced probing depth (3 mm), no mobility, resolution of apical translucency, radiographic findings suggestive of canal narrowing, and a positive pulp sensibility response. Re-entry elicited profuse bleeding with newly formed vital tissue beneath the medicament. Sodium hypochlorite irrigation failed to achieve hemostasis; inflamed tissue was removed; root canals were cleaned, shaped and obturated; and treatment was completed with placement of a permanent coronal resin composite restoration. A forty-month follow-up showed an asymptomatic tooth with clinical and radiographic healing. Conclusions: This case demonstrates that conservative endodontic management may result in favorable clinical and radiographic outcomes in mature teeth with severe endo-peroidontal involvement, influencing extraction decisions. It provides clinical evidence suggestive of tissue regeneration and periodontal healing in a mature tooth with necrotic pulp and severe periodontal compromise, challenging conventional prognosis. The observed pulp space tissue growth may be suggestive of regeneration; however, alternative explanations, including granulation tissue healing or repair processes, cannot be excluded. Healing by granulation tissue in the pulp space remains possible. Root canal treatment in advanced endo-perio lesions can yield favorable outcomes and may influence extraction decisions. Further clinical and histological studies are needed to clarify underlying mechanisms and optimize treatment strategies. Full article

Head and neck mucosal melanoma (HNMM) arises in the nasal and oral cavities and has the propensity to metastasize to local and distant body sites. HNMM is also notable for its resistance to available therapeutics. The rarity of this disease makes it difficult to conduct large-scale clinical studies to develop standard treatment protocols. In contrast to cutaneous melanoma, c-Kit-dependent pathways are well studied in HNNMM and provide a potential therapeutic target. We identified and isolated genetically distinct subpopulations with stem cell characteristics in HNMM samples bearing Kit wild-type and mutations. Functional analysis of these subpopulations reveals that, in addition to expressing the stem cell marker proteins CD20, CD117, CD133, and CD166, these subpopulations are characterized by self-renewal potential, migratory capacity, and resistance to Kit inhibitors such as Imatinib. Immunofluorescence staining and inhibition experiments demonstrate that the maintenance and resistance of HHMM subpopulations to Kit inhibitors is mediated by the Kit signal to the PI3K signaling pathway. The KIT signal to the PI3K signaling pathway does not result exclusively from a KIT mutation localized to Exon 17, but can also be triggered by mutations localized to Exons 11 and 13. In the present study, we identify and characterize an HNMM subpopulation with stemness properties in patients with c-Kit wild-type and mutation, and demonstrate for the first time the mechanisms by which the CD117⁺/CD133⁺ HNMM subpopulations survive and confer resistance to the specific inhibitor of c-Kit mutation. Full article

Introduction: Three-dimensional (3D) bioprinting is a promising approach for endodontic tissue engineering, enabling scaffolds with controlled architecture and bioactivity to support pulp regeneration. Objectives: This systematic review assessed the following: “What 3D bioprinting applications are reported in endodontics-related studies?” Materials and Methods: Following PRISMA 2020 guidelines, PubMed/MEDLINE, Scopus, Embase, Cochrane Library, Web of Science, SciELO, LILACS, and Google Scholar were searched up to January 2026 with no date or language limits. Two reviewers independently screened studies; risk of bias in in vitro studies was assessed with the QUIN tool. As only one study reported complete antimicrobial outcomes, an intra-study quantitative comparison (MD, 95% CI) of inhibition halos was performed (not a meta-analysis). Results: From 518 records, nine studies were included. Outcomes mainly addressed physicochemical properties (n = 9), cell viability (n = 7), biocompatibility (n = 5), and cell differentiation (n = 5); antimicrobial activity was evaluated in two studies. Most used hDPSCs and extrusion-based printing, testing calcium silicate composites, alginate hydrogels, functionalized PCL, and modified PLA. Modified PLA scaffolds showed greater antimicrobial activity, strongest with naringin and nHA formulations. Overall risk of bias was moderate (58.33%), largely due to limited reporting of randomization, blinding, and sampling. Conclusion: 3D-bioprinted scaffolds/bioinks generally improved cellular responses and bioactivity, especially with MTA, Biodentine, nHA, or naringin; antimicrobial effects were most evident in functionalized PLA (PLA/NAR and PLA/nHA/NAR). Full article

This study investigated the radiopacity, elemental composition, cytotoxicity, and cytokine responses of contemporary calcium silicate-based cements containing different radiopacifiers. Four cement materials (NeoMTA2, NeoPUTTY, TheraCal PT, and One-Fil PT) were evaluated. Radiopacity was measured using digital radiography with a 10-step aluminum wedge and expressed in mm Al in accordance with ISO 6876; among three calibration models compared, the quadratic provided the best fit. Elemental composition was analyzed by SEM/EDX. Cytotoxicity was assessed on human dental pulp cells using the MTT assay, and IL-6 and IL-10 levels were quantified by ELISA. One-Fil PT (6.61 mm Al) and NeoPUTTY (6.09 mm Al) showed the highest radiopacity, whereas TheraCal PT (1.61 mm Al) did not meet ISO standards. SEM/EDX revealed tantalum in NeoMTA2 and NeoPUTTY, and zirconium in One-Fil PT and TheraCal PT. NeoPUTTY and NeoMTA2 demonstrated superior cell viability, while One-Fil PT showed the lowest. TheraCal PT and One-Fil PT increased IL-6 expression, whereas NeoPUTTY and NeoMTA2 promoted higher IL-10 levels. Within the limitations of this 24-h in vitro assessment, NeoMTA2 and NeoPUTTY exhibited more favorable short-term cytocompatibility and inflammatory profiles together with adequate radiopacity. These findings require confirmation through long-term in vivo and clinical studies. Full article

The aim of this study was to evaluate setting time, hardness, solubility, bioactivity and interaction with dentin of four calcium silicate-based sealers (CSBS). Three single-phase CSBS (AH Plus Bioceramic/AHB, CeraSeal/CSL, TotalFill BC/TFL), one powder/liquid CSBS (BioRoot RCS/BRT) and an epoxy control (AH Plus Jet/AHP) were investigated. Setting time was evaluated on glass (G1) and dentin (G2) surfaces, by adding 1%wt purified water to single-phase products. For hardness measurements, the Shore-D hardness test was used. Solubility was assessed according to the ISO 6876:2012 standard. For bioactivity screening, 1-week set specimens were immersed in SBF or water (30 days/37 °C) and examined by ATR–FTIR spectroscopy. Interaction with dentin was tested by ATR–FTIR before and after contact with the sealers. For setting time in G1, all CSBS failed to comply with the ISO standard, while in G2, most materials were set in the range of 6–8 h, except for CSL. The ranking of significant differences in hardness was AHP, BRT > CSL, AHB, TFL. Regarding solubility, AHB, BRT and AHP were found to comply with the ISO standard, whereas CSL and TFL failed. For bioactivity, characteristic peaks of calcium phosphates were found in all CSBS, with TFL being the most bioactive. A chemical interaction between CSBS and dentin was registered, with a strong reduction in collagen peaks and an increase in carbonates. The CSBS tested exhibited great variance in their behaviour regarding the properties assessed, although a strong deproteinating effect was registered on dentin for all. Full article

Background/Objectives: Intraoral radiographs acquired using photostimulable phosphor (PSP) plates are inherently susceptible to a wide spectrum of artifacts that can compromise diagnostic reliability and lead to unnecessary repeat exposures. Although structured taxonomies describing these artifacts have been proposed, automated methods capable of detecting and localizing multiple artifact types at the pixel level remain limited, particularly under realistic multi-class conditions. In this study, we address the problem of fine-grained, multi-class PSP artifact segmentation by systematically evaluating a deep learning-based framework and establishing a realistic baseline for this inherently challenging task. Methods: A retrospective, multi-center dataset comprising 1497 intraoral PSP radiographs (bitewing and periapical) collected from three institutions was analyzed. Pixel-level annotations were generated by expert oral and maxillofacial radiologists according to a standardized taxonomy consisting of four major artifact groups and 29 artifact classes, together with a background class. A 2D nnU-Net v2 architecture was employed as a baseline segmentation model. Model development was performed using 5-fold cross-validation, and performance was evaluated on an independent test set using Dice coefficient, Intersection over Union (IoU), Precision, and Recall. Results: Across all classes, the model achieved a mean Dice score of 0.0894 ± 0.0084 in cross-validation and 0.0952 on the independent test set, reflecting the intrinsic complexity of the task. Class-wise analysis revealed substantial variability, with higher performance in larger and visually distinctive artifacts, whereas small-scale, low-contrast, and underrepresented classes exhibited markedly reduced performance. Notably, several artifact categories were absent from the training data, resulting in a zero-shot scenario that directly constrained model generalization. Furthermore, segmentation performance demonstrated a strong dependency on class frequency, measured in terms of pixel distribution, underscoring the impact of severe class imbalance. Group-based evaluation showed relatively higher performance for pre-exposure and exposure-related artifacts compared to post-exposure and scanner-related categories. Conclusions: These findings demonstrate that large-scale, multi-class pixel-level segmentation of PSP artifacts represents a fundamentally challenging problem shaped by the combined effects of class imbalance, small object size, heterogeneous artifact morphology, and incomplete training representation. While the proposed framework confirms the feasibility of automated artifact localization, its current performance suggests greater immediate value as a quality control or screening support tool rather than a fully autonomous diagnostic system. By providing a comprehensive baseline and systematic analysis, this study establishes a benchmark for future research and highlights the critical need for imbalance-aware learning strategies, hierarchical modeling, and data-centric approaches to advance this field. Full article

Background: Oral biofilms are a major etiological factor in dental caries, periodontal disease, peri-implantitis, and endodontic infections. Increasing antimicrobial resistance and the limitations of conventional therapies have intensified interest in antimicrobial photodynamic therapy (aPDT). Hypericin, a natural photosensitizer derived from Hypericum perforatum, demonstrates potent reactive oxygen species generation and broad antimicrobial activity; however, its dental applications remain insufficiently synthesized. Objective: To systematically evaluate the antimicrobial efficacy, treatment parameters, safety, and clinical potential of hypericin-mediated aPDT against oral biofilms and infections in dentistry. Methods: This systematic review was conducted according to PRISMA 2020 and registered in PROSPERO CRD42024617727. Electronic searches of PubMed/MEDLINE, Embase, Scopus, and the Cochrane Library (January 2010 to December 2025) were performed. Studies assessing hypericin-mediated aPDT in oral or dental contexts were included. Methodological quality was evaluated using a predefined nine-domain risk-of-bias tool. Results: Eleven studies met the inclusion criteria. Hypericin-mediated aPDT demonstrated strong antimicrobial effects, achieving up to 99% planktonic inactivation and significant biofilm reduction across bacterial and fungal species. Activity was particularly pronounced against Gram-positive organisms, including Staphylococcus aureus and Enterococcus faecalis. However, efficacy against mature biofilms was variable and often dependent on formulation and irradiation parameters. Most studies showed moderate methodological quality, with frequent deficiencies in reporting light calibration and dosimetry. Advanced delivery systems, including liposomal and nanoparticle formulations, improved photodynamic performance. Conclusions: Hypericin-mediated aPDT shows promising antimicrobial activity against oral pathogens and biofilms, with favorable selectivity and safety profiles. Nevertheless, the evidence remains predominantly preclinical and heterogeneous. Standardized protocols and well-designed clinical trials are required before routine dental implementation can be recommended. 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

Objectives: Due to extra-axial forces, post and core (PC) treatment has the worst survival probability in abutment teeth for telescopic crown-retained dentures (TCDs). The reason for this is a mismatch regarding the mechanical properties between PC material and dentin or a poor accuracy of fit of PC, resulting in tooth fracture or decementation. However, the inclusion of severely damaged endodontically treated teeth needing PC is often mandatory in order to achieve a stable situation for TCD. Thus, an advancement of PC treatment for TCD is of high clinical interest. Recently it has become possible to fabricate customized PC with favourable mechanical properties by using CAD/CAM technology. Methods: Thus, the aim of this investigation was to compare the performance of these PC types (CAD/CAM PC) to customized cast PC (CPC) and prefabricated fibre-reinforced PC (PFPC) in a TCD set-up using a chewing simulator. Results: The investigation group with CAD/CAM PC showed neither tooth fracture nor decementation, in contrast to the CPC and PFPC groups, in which both types of failure were recorded. Thus, CAD/CAM PC showed significantly better performance than CPC and PFPC. Conclusions: Within the limitations, CAD/CAM PCs are therefore recommendable for PC treatment with TCD. 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

This in vitro study evaluated and compared the surface roughness, color stability, and gloss of two single-shade composite resins after simulated toothbrushing, and investigated the correlations among these parameters. Twenty disk-shaped specimens (n = 10 per group) were prepared from two single-shade composite resins (Material A and Group B) and subjected to simulated toothbrushing up to 15,000 cycles. Surface roughness (Ra) was measured at baseline and after 5000, 10,000, and 15,000 cycles. Color parameters (CIE Lab*) and gloss (60°) were measured at baseline and after 15,000 cycles. Color change was calculated using the CIEDE2000 formula (ΔE₀₀). Data were analyzed using two-way mixed ANOVA, t-tests, and Pearson correlation analysis (α = 0.05). Both materials showed progressive increases in surface roughness. Material B exhibited significantly higher Ra values than Material A from 10,000 cycles onward (p < 0.01). After 15,000 cycles, Material B demonstrated significantly greater color change (ΔE₀₀: 2.21 ± 0.18 vs. 1.48 ± 0.13; p < 0.001), exceeding the acceptability threshold (ΔE₀₀ = 1.8), while Material A remained clinically acceptable. Material B also showed greater gloss reduction (60% vs. 35%; p < 0.001). Strong correlations were found between surface roughness and both gloss change (r = −0.919) and color change (r = 0.826). Material A demonstrated greater resistance to surface degradation and better preservation of optical properties compared to Material B. Surface roughness was identified as the common underlying factor driving both color instability and gloss reduction in single-shade composites. Clinical Significance: Not all single-shade composites perform equally under mechanical aging. Clinicians should consider the filler technology and long-term surface stability when selecting single-shade composite resins for clinical use. Full article