Search Results (398)

Background and Objectives: The regeneration of the pulp–dentin complex represents an alternative to conventional root canal treatment, aiming to preserve tooth biology and function. Cell-free regenerative endodontic therapy (CF-RET) exploits endogenous stem cells from the periapical region without ex vivo cell manipulation. Despite growing interest, the biological mechanisms, clinical indications, and predictability of CF-RET remain not clearly defined. This structured narrative review aimed to update a previous review by analyzing recent human studies on CF-RET. Materials and Methods: This review was conducted using the PRISMA 2020 guidelines to guide transparent reporting of the literature search and study selection process and was registered in PROSPERO (CRD420251075131). In vitro and in vivo human studies published between January 2017 and December 2024 investigating CF-RET were included, while studies involving cell transplantation, non-human models, case reports, and reviews were excluded. Study selection, data extraction, and quality assessment using the QuADS tool were performed, and the evidence was synthesized using a qualitative narrative approach. Results: Sixty-four studies were included. In vitro studies reported favorable effects of growth factors, exosomes, and biomimetic scaffolds on stem cell viability, migration, proliferation, odontogenic differentiation, and angiogenesis, while neurogenic differentiation was less consistently investigated. Scaffold composition, microstructure, and rheological properties were also considered. In vivo studies mainly focused on immature teeth with incomplete root development and demonstrated positive clinical and radiographic outcomes, including root development and canal diameter reduction. Conclusions: The current evidence supports the biological potential of CF-RET as a regenerative approach; however, substantial heterogeneity, the limited number of clinical studies and the absence of standardized protocols preclude definitive conclusions, highlighting the need for further well-designed translational and clinical investigations considering clinical applicability. Full article

Background/Objectives: This study aimed to compare the cleaning efficacy, biomechanical stress distribution under simulated occlusal loading after instrumentation, and irrigant dynamics of three NiTi rotary systems, namely ProTaper Gold, TruNatomy, and SlimShaper, using a combined experimental, finite element analysis (FEA), and computational fluid dynamics (CFD) approach. Methods: Transparent 3D replicas of mandibular mesial roots filled with a gel-like pulp tissue were instrumented with the three systems (n = 13 per group). Standardized irrigation was performed with 4% NaOCl delivered through IrriFlex^® needles positioned 2 mm from the working length. Cleaning effectiveness was assessed through digital image analysis, FEA simulation of occlusal loading, and CFD evaluation of irrigation flow, wall shear stress, and dynamic pressure. Results: All systems left residual tissue, with no statistically significant differences in cleaning efficacy among them (p > 0.05). Descriptively, ProTaper Gold showed the lowest mean residual tissue (0.15 ± 0.25%), followed by SlimShaper (2.50 ± 3.81%) and TruNatomy (4.20 ± 5.12%). CFD revealed that ProTaper Gold generated the highest irrigant velocities and wall shear stresses, while SlimShaper showed the highest dynamic pressure. FEA indicated that ProTaper Gold produced the highest stress concentrations, especially in the pericervical dentin, whereas TruNatomy and SlimShaper preserved more dentin. Conclusions: Cleaning efficacy was comparable across systems. CFD/FEA from representative models illustrated patterns of irrigant dynamics and dentin preservation without supporting system superiority. Full article

Ex vivo human tooth culture models preserve the native dentine–pulp complex and offer a translational platform to study pulp-capping biomaterials. This systematic review aimed to synthesize the evidence on histological pulp tissue responses to calcium silicate-based cement (CSCs) used for direct pulp capping in human tooth culture models. The review followed PRISMA 2020 guidance. Eligible studies were ex vivo whole human tooth culture models with direct pulp exposure treated with commercial or experimental CSCs and reporting histological outcomes. Risk of bias was assessed using the QUIN tool. Thirteen studies were included. Most used immature human third molars (from 15- to 19-year-old patients) and culture periods up to 28 days, with a minority extending observation to 45–90 days. Across hydraulic CSCs, Biodentine was the most frequently evaluated material, followed by ProRoot MTA and several experimental hydraulic and resin-modified formulations. Overall, hydraulic CSCs were consistently associated with biocompatible pulp responses and a pro-mineralization pattern characterized by periexposure mineralized foci/osteodentin-like tissue; where assessed, immunohistochemistry supported odontoblast-like differentiation. In contrast, the resin-modified CSC TheraCal LC and other experimental resin-modified CSCs showed more heterogeneous findings, with reports of absent, delayed, or less prominent mineralization compared with reference hydraulic CSCs. In intact human tooth culture models, hydraulic CSCs show reproducible biocompatibility and early mineralization features consistent with reparative dentinogenesis, whereas resin-modified CSCs demonstrate more variable histological performance. Full article

A three-dimensional finite element analysis (FEA) was performed to evaluate stress accumulation and distribution in endodontically treated immature and mature mandibular molars restored with endocrowns. Three tooth models representing different stages of root development (Cvek 2, Cvek 3, and mature) were generated from cone-beam computed tomography data. Endocrowns were fabricated using lithium disilicate (LDS) and resin nanoceramic (RNC). In immature teeth, two apexification strategies were simulated: a 3 mm mineral trioxide aggregate (MTA) apical plug followed by gutta-percha obturation, and complete canal obturation with MTA. All models were subjected to axial (600 N) and oblique (200 N) loading. A total of 20 finite element models were analysed. Endocrown material and loading direction were the main factors affecting von Mises stress distribution, whereas root development stage and apexification technique showed limited influence. LDS resulted in reduced stress transmission to the residual dentin, despite higher stress accumulation within the restoration itself. In the LDS groups, von Mises stress values in the root dentin ranged from 35.24 to 35.96 MPa under oblique and from 42.93 to 44.45 MPa under axial loading, while the RNC group exhibited higher values (39.36–40.40 MPa and 51.59–53.66 MPa, respectively). These findings indicate that endocrown restoration after apexification is a reliable treatment option for immature mandibular molars with extensive structural loss, with LDS demonstrating more favorable biomechanical behavior. Full article

Reconstructing original cusp dimensions in worn molars represents a fundamental challenge across dentistry, anthropology, and paleontology, as dental wear obscures critical morphological information. In this proof-of-concept study, we present a standardized machine learning pipeline for predicting original cusp height, specifically the horn tips of the enamel–dentine junction (EDJ), in worn lower molars using three-dimensional morphometric data from micro-computed tomography (micro-CT). We analyzed 40 permanent lower first (M1) and second (M2) molars from four hominin groups, systematically evaluated across three wear stages: original, moderately worn (worn1), and severely worn (worn2). Morphometric variables including height, area, and volume were quantified for each cusp, with Random Forest and multiple linear regression models developed individually and combined through ensemble methods. To mimic realistic reconstruction scenarios while preserving a known ground truth, models were trained on unworn specimens (original EDJ morphology) and tested on other teeth after digitally simulated wear (worn1 and worn2). Predictive performance was evaluated using root mean square error (RMSE) and coefficient of determination (R²). Our results demonstrate that under moderate wear (worn1), the ensemble models achieved normalized RMSE values between 11% and 17%. Absolute errors typically below 0.25 mm for most cusps, with R² values up to ~0.69. Performance deteriorated under severe wear (worn2), particularly for morphologically variable cusps such as the hypoconid and entoconid, but generally remained within sub-millimetric error ranges for several structures. Random Forests and linear models showed complementary strengths, and the ensemble generally offered the most stable performance across cusps and wear states. To enhance transparency and accessibility, we provide a comprehensive, user-friendly software pipeline including pre-trained models, automated prediction scripts, standardized data templates, and detailed documentation. This implementation allows researchers without advanced machine learning expertise to explore EDJ-based reconstruction from standard morphometric measurements in new datasets, while explicitly acknowledging the limitations imposed by our modest and taxonomically unbalanced sample. More broadly, the framework represents an initial step toward predicting complete crown morphology, including enamel thickness, in worn or damaged teeth. As such, it offers a validated methodological foundation for future developments in cusp and crown reconstruction in both clinical and evolutionary dental research. Full article

Background/Objectives: This study evaluates the penetration of a calcium silicate-based sealer (BC Universal) into dentinal tubules after different final irrigation protocols. Methods: Eighty-four single-rooted extracted teeth were instrumented with ProTaper Gold to size F4 and assigned to four groups (n = 21) according to the final irrigation protocol as follows: conventional needle irrigation (CNI), sonic agitation with EndoActivator (EA), ultrasonic activation (UA), and XP-Endo Finisher (XPF). A total of 20 canals from each group were filled with BC Universal sealer mixed with fluorescein and the single-cone obturation technique. The remaining specimen in each group served as a negative control to assess potential imaging bias. Specimens were sectioned 3 mm from the apex and analyzed under confocal laser scanning microscopy. Sealer penetration was assessed by penetration area (PA), maximum depth (MaxD), mean depth (MeanD), and percentage of canal perimeter infiltrated (P). Data were analyzed using Kruskal–Wallis or ANOVA tests (α = 0.05). Results: All activation/agitation techniques showed significantly higher penetration than CNI across all variables (p < 0.001). No significant differences were found among EA, PUI, and XPF for PA, MaxD, and MeanD. However, XPF exhibited the highest perimeter infiltration, which was significantly greater than EA and UA (p < 0.001). Conclusions: Irrigant activation significantly enhanced dentinal tubule penetration of BC Universal sealer compared to CNI. XPF provided superior P, suggesting superior circumferential distribution. These findings suggest a more effective cleaning of the root canal in the apical third achieved by the tested irrigant activation/agitation techniques, which may improve the sealing potential of BC Universal sealer. Full article

Vital pulp therapy (VPT) is increasingly recognised as a biologically driven alternative to root canal treatment in teeth with deep caries and a vital pulp diagnosis. Resin-modified calcium silicate-based materials (RM-CSMs) were introduced to combine the bioactivity of traditional cements with improved handling and immediate light-curing, but their biological performance remains debated. Objectives: This systematic review and meta-analysis aimed to evaluate the clinical and radiographic outcomes of VPT performed with RM-CSMs compared with conventional non-resin-modified calcium silicate-based materials (NRM-CSMs) Methods: PRISMA Guidelines were followed to carry out this systematic review. Electronic databases (Medline, Embase, Scopus, and Web of Science) were searched up to October 2025 for randomised clinical trials evaluating indirect pulp capping, direct pulp capping, or pulpotomy. Nine trials met the inclusion criteria. Meta-analyses were performed for TheraCal LC, the only RM-CSM with sufficient clinical evidence. The risk of bias was assessed using the RoB 2 Tool. The certainty of evidence was assessed using GRADE. Results: Pooled results showed no significant differences in overall clinical–radiographic success between RM-CSMs and NRM-CSMs at 90 or 180 days. At 360 days, a trend favouring NRM-CSMs emerged, though not statistically significant. Dentine bridge formation at 360 days was significantly lower with TheraCal LC. Conclusions: Current RM-CSMs demonstrate comparable short-term success to conventional materials but still present biological limitations, particularly regarding long-term reparative outcomes. NRM-CSMs remain the preferred option when maximal bioactivity and predictable dentinogenesis are required Full article

Objectives: This study evaluated the effect of three root canal filling material (RCFM) removal techniques—mechanical, thermo-mechanical, and chemico-mechanical—on the micro push-out bond strength of fiber posts to root dentin in endodontically treated teeth. Materials and Methods: Forty-five single-rooted human premolars were endodontically treated and randomly allocated into three groups (n = 15) according to the RCFM removal technique used during post-space preparation: mechanical, thermo-mechanical, or chemico-mechanical. Fiber posts were luted using a dual-cure resin cement. Roots were embedded in resin and sectioned into coronal, middle, and apical thirds. Micro push-out bond strength was measured using a universal testing machine. Failure modes were examined under a stereomicroscope and validated using scanning electron microscopy. Statistical analysis used two-way ANOVA and Chi-square tests (α = 0.05). Results: Both the thermo-mechanical and mechanical groups showed significantly higher bond strength values than the chemico-mechanical group (p < 0.001). Across all groups, the coronal third recorded the highest bond strength, while the apical third presented the lowest values (p < 0.001). Adhesive failure at the dentin–cement interface was the most frequent failure mode. Conclusions: The gutta-percha removal technique and the root canal region significantly influence fiber-post bond strength. Solvent-based chemico-mechanical methods may adversely affect adhesion quality. Clinical Relevance: Thermo-mechanical and mechanical removal techniques may provide more reliable post retention during retreatment procedures, improving adhesion and reducing the risk of post debonding in daily practice. Full article

Objectives: This study evaluated and compared the sealing ability and elemental composition of a resin-based endodontic sealer (AH Plus) used with three root canal obturation techniques: single cone (SC), lateral compaction (LC), and warm vertical condensation (WVC). The investigation focused on microstructural characteristics, interfacial integrity, and elemental distribution within filled root canals. Material and Methods: Sixty extracted single-root teeth were instrumented using the ProTaper Gold system and randomly assigned to three groups (n = 20) according to the obturation technique. The AH Plus Jet sealer was applied in all cases. Following obturation, samples were subjected to radiographic investigation and analyzed using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) to assess the sealing performance and chemical composition. Results: Radiographic and microscopic assessments indicated that the SC method showed strong gutta-percha adhesion to dentin with a thin cement layer, whereas WVC provided excellent adaptation and penetration of gutta-percha. The LC technique demonstrated good adhesion but displayed occasional structural irregularities. SC has the thicker adhesion layer with uneven distribution regarding coronal, median, and apical, regions ranging from 45 to 80 μm, while WVC ensures a thin and uniform sealing layer of about 35 μm in all regions. SEM and EDX analyses detailed the interfacial microstructure and confirmed the presence of carbon (C), oxygen (O), calcium (Ca), zinc (Zn), barium (Ba), and sulfur (S) across all groups. Conclusions: All three obturation techniques (SC, WVC, LC) achieved effective sealing when combined with the AH Plus sealer. The main difference between the methods consists of the sealer layer thickness and its even distribution regarding gutta-percha cones. Full article

This study evaluated the push-out bond strength (PBS) and failure modes of fiber posts cemented with silane-containing self-adhesive resin cement (SARC) compared with conventional SARC and universal adhesive strategies, considering the effects of root section and aging. Ninety single-rooted human premolars were equally assigned to three cementation protocols: silane-containing SARC (PANAVIA SA Cement Universal), conventional SARC (RelyX Universal), and universal adhesive plus SARC (Scotchbond Universal Plus + RelyX Universal). Each group was divided into two aging subgroups: 24 h water storage and thermal cycling (10,000 cycles between 5 °C and 55 °C, 30 s dwell time; n = 15). After root canal treatment and post space preparation, glass fiber posts were cemented, and each root was sectioned to obtain six slices. PBS was measured using a push-out test, and failure modes were examined under stereomicroscopy. Data were analyzed using three-way ANOVA, post hoc tests, Spearman’s correlation, and logistic regression (α = 0.05). Cement type, root section, and aging significantly influenced PBS (p < 0.001). PBS decreased from coronal to apical sections, and thermal cycling reduced PBS in all groups. The universal adhesive plus SARC achieved the highest PBS, while conventional SARC had the lowest PBS. Cementdentin adhesive failures (FM2) predominated overall, with proportions varying between 43% and 90%, and higher PBS values were associated with fewer FM2 failures. The combination of a universal adhesive with SARC provided superior bonding compared to simplified protocols. Although silane-containing SARC improved bonding relative to conventional SARC, durable adhesion to radicular dentin remains challenging, particularly in apical regions. Full article

Background: X-linked hypophosphatemic rickets (XLH) is a rare hereditary disorder characterized by renal phosphate wasting and impaired bone mineralization. Oral manifestations such as spontaneous periapical lesions and dental abscesses in the absence of caries or trauma may precede systemic features in XLH due to underlying dentin hypomineralization and enamel–dentin junction defects, and could serve as early diagnostic indicators. Case Report: We report on the case of a 4-year-old boy referred to our pediatric dental unit with recurrent intraoral fistulas persisting over the past year. Clinical examinations and an orthopantomogram revealed extensive root resorption and periapical pathology affecting multiple primary molars without evident caries or trauma. Laboratory investigations showed hypophosphatemia, elevated renal phosphate loss, and raised inflammatory markers (CRP (C-reactive protein) and granulocytes). Genetic testing of the child and his mother confirmed a diagnosis of X-linked hypophosphatemic rickets. Management: Due to behavioral challenges, treatment proceeded with difficulty over multiple visits. Endodontic treatment was initiated using a formalin–resorcinol technique; however, several primary molars developed progressive necrosis and required extraction. Orthodontic space maintainers were placed to preserve arch integrity and support future eruption. The patient remains under follow-up and is currently awaiting Burosumab therapy. Despite systemic management, spontaneous necroses of the primary molars persist, highlighting the refractory nature of dental involvement in XLH. Conclusions: This case underscores the pivotal role of pediatric dentists in recognizing systemic diseases through oral findings and demonstrates the challenges of managing XLH-related dental pathology, even under targeted systemic therapy. Early interdisciplinary collaboration is essential to optimize both dental and systemic outcomes in affected children. Full article

Background/Objectives: Diode lasers are used as adjuncts for endodontic disinfection, but their depth-resolved effects on root dentin are insufficiently described. This ex vivo study used optical coherence tomography (OCT) to qualitatively document laser-related morphological signatures on canal walls. Methods: Palatal roots from extracted maxillary first molars were standardized and hemisectioned to create specimens allocated to a conventional diode-laser protocol, a higher-power protocol, or control. A 940-nm diode laser with endodontic tips was applied per group. Swept-source OCT acquired serial B-scans along the root length. Two endodontists reviewed images for thermally induced morphological alterations (TIMAs). Reporting is descriptive. Results: OCT revealed laser-related hyper-reflective linear/radial signatures extending from the canal lumen toward the external root surface in laser-treated specimens. Qualitatively, signatures appeared more conspicuous and extended deeper with the higher-power protocol than with the conventional protocol. Findings were most evident in the coronal/middle thirds. Control specimens served to contextualize background appearances from preparation and sectioning. Representative B-scans illustrate typical patterns. The novelty of the present study results from the identification of areas of morphological alteration through the OCT examination of the walls of the root canals. Conclusions: Depth-resolved OCT can visualize dentinal alterations associated with diode-laser irradiation in an ex vivo model. These observations support careful parameter selection and motivate in situ studies with concurrent temperature monitoring and histologic correlation. Full article

Background/Objectives: Important goals of endodontic treatment procedures are to effectively eliminate microorganisms from the root canal system and prevent reinfection. Despite advances in techniques, these goals continue to be difficult to achieve due to the complex anatomy of the root canal system and bacterial invasion into the dentinal tubules of the surrounding root dentin. This pilot study aimed to refine a confocal laser scanning microscopy (CLSM) model with LIVE/DEAD staining to quantitatively assess the depth of effective disinfection by endodontic disinfection measures. Methods: Thirty caries-free human teeth underwent standardized chemo-mechanical root canal preparation and were inoculated with Enterococcus faecalis. Following treatment, CLSM-guided imaging with LIVE/DEAD staining allowed for differentiation between vital and dead bacteria and quantification of the depth of effective disinfection. Results: An average depth of bacterial eradication of 450 µm for conventional and 520 µm for sonically activated irrigation (EDDY) could be observed with significant differences (p < 0.05) in the coronal and medial positions. Conclusions: The results indicated that sonically activated irrigation (EDDY) provided a more homogeneous (omnidirectional) irrigation pattern compared to conventional irrigation. The study highlights the importance of effective disinfection strategies in endodontics, emphasizing the need for further research on the depth of effective disinfection of endodontic disinfection measures and the optimization of disinfection protocols. Full article

This study investigates the bactericidal efficacy and penetration ability inside dentinal tubules of calcium hydroxide (CH) and a modified tri-antibiotic paste (ciprofloxacin, metronidazole, clarithromycin) (TAP) during regenerative endodontic procedures (REPs). The blood clot serving as a biological scaffold was introduced into the root canal to assess its influence on bacterial regrowth. Forty-four human extracted teeth were infected with E. faecalis and divided in four experimental groups (N = 10) with positive and negative controls (N = 4). Samples were treated with either CH or TAP as intracanal dressing. Bacterial viability and depth of penetration were evaluated using confocal laser scanning microscopy (CLSM) after fluorescent vital staining. The same analysis was performed with or without blood clot exposure and the data were analyzed by one-way ANOVA and a post hoc Bonferroni test (p < 0.05). TAP demonstrated significantly stronger bactericidal activity than CH (p = 0.008). However, its efficacy significantly decreased in the presence of blood clot (p = 0.032). CH showed a moderate antibacterial effect, with its efficacy reduced in the presence of blood. Blood clot exposure consistently reduced the bactericidal efficacy in both groups (p = 0.01) and the dye penetration in CH group (p = 0.041). In conclusion, TAP demonstrated superior antibacterial performance compared to CH and blood clot exposure seemed to decrease antimicrobial efficacy and depth of disinfection during REPs. Full article

Background/Objectives: Non-surgical retreatment aims to remove infected filling material, prepare the canal for disinfection, and re-obturate. This ex vivo study evaluated the residual filling material and dentin volume removed after retreatment using a rotary or reciprocating system. Methods: Twenty mesial roots of mandibular molars with two independent, straight canals were decoronated to a 16 mm working length and obturated. Pre-operative nano-CT scans measured the initial dentin and filling material volumes. Specimens were randomly assigned to two groups: Solite RE Black system (RE1-30/0.08; RE2-20/0.06) and WaveOne Gold—small file (20/0.07). Post-operative nano-CT scans were superimposed to calculate the remaining filling material and dentin volume removed. Data are presented as the mean ± SD, and groups were compared using independent t-tests. Results: Neither system completely removed the intracanal filling material. The mean residual filling material volume was 1.42 ± 0.21 mm³ (Solite RE Black) vs. 1.56 ± 0.27 mm³ (WaveOne Gold), representing approximately 14% vs. 16% of the initial filling material, respectively (p < 0.05). Mean dentin volume removed was 0.95 ± 0.18 mm³ vs. 1.12 ± 0.22 mm³, with no significant difference (p > 0.05). Conclusions: In single-rooted, straight canals, Solite RE Black removed more filling material than WaveOne Gold, while dentin loss was similar. These findings are specific to straight canals, and further studies are required for curved or multi-rooted teeth. Full article