Iranian Endodontic Journal

Dens invaginatus (DI) is a developmental dental anomaly characterized by the invagination of the enamel organ into the dental papilla during tooth development, often resulting in complex root canal anatomy and increased susceptibility to pulpal disease. Gemination is another uncommon developmental anomaly resulting from the incomplete division of a single tooth germ, which produces an enlarged or bifid crown. The simultaneous occurrence of these anomalies in a single tooth is extremely rare. This case report describes the diagnosis and nonsurgical endodontic management of a maxillary lateral incisor presenting with both gemination and Oehlers type II dens invaginatus. A 14-year-old female patient was referred for further endodontic management of the maxillary left lateral incisor. Normal apical tissues were diagnosed, and the referring practitioner previously initiated endodontic therapy. Clinical examination revealed a bifid crown morphology, while cone-beam computed tomography (CBCT) demonstrated type II dens invaginatus associated with gemination and a complex root canal system with apical bifurcation. Root canal treatment was performed under dental operating microscope magnification using nickel-titanium rotary instrumentation, passive ultrasonic irrigation, and calcium hydroxide intracanal medication. The root canal system was subsequently obturated using gutta-percha and AH-Plus sealer by the cold lateral compaction technique. At the 12-month follow-up, the tooth remained asymptomatic and exhibited normal clinical and radiographic findings. This case highlights the importance of CBCT and magnification-assisted endodontic treatment in the successful management of rare developmental anomalies with complex internal anatomy.

Teeth diagnosed clinically with pulp necrosis and apical periodontitis may occasionally retain vital radicular pulp tissue despite negative sensibility test responses. Such diagnostic discrepancies highlight the limitations of conventional pulp testing and may create opportunities for biologically based treatment approaches. This case report describes the successful management of a mature permanent molar initially diagnosed as necrotic but found intraoperatively to contain vital radicular pulp tissue. A 36-year-old healthy patient presented with pain on chewing and tenderness to percussion in the left mandibular second molar. Clinical and radiographic examination revealed severe coronal destruction, a periapical radiolucency, and a negative response to cold testing, leading to a preoperative diagnosis of pulp necrosis with apical periodontitis and a treatment plan for root canal therapy. However, during access cavity preparation, profuse bright-red bleeding from the canal orifices indicated retained vital radicular pulp tissue. Consequently, treatment was changed to full pulpotomy. Because hemostasis could not be achieved after 5 minutes using 2.5% sodium hypochlorite-soaked cotton pellets, a tampon technique was performed with calcium-enriched mixture cement placed over the radicular pulp stumps, followed by definitive restoration. The patient became symptom-free within one week and remained asymptomatic throughout the 4-year follow-up period. Radiographic examination demonstrated complete resolution of the periapical lesion, re-establishment of the lamina dura, and normalization of the periodontal ligament space. This case demonstrates that teeth initially diagnosed as necrotic may still harbor maintainable vital radicular pulp tissue. Careful intraoperative assessment can alter both diagnosis and treatment strategy. Full pulpotomy using an endodontic biomaterial and a tampon technique resulted in complete clinical and radiographic healing over four years.

Abstract:

Introduction:

Advances in endodontic instrumentations are centred around in the innovation of variable metallurgy and designs of endodontic files to reduce procedural errors. However, there is a lack of consensus in literature with regards to shaping ability of WOG and PTN endodontic file system in curved root canal.

Objectives:

To measure and compare the amount of canal transportation (CT) and centring ability (CA) in coronal, middle and apical thirds of root canals prepared using WaveOne Gold File and Protaper next system using CBCT.

Material and Method:

A total of sixty single rooted teeth with Type I Vertucci canal and moderate 10°-30°canal curvature according to AAE guidelines  were collected and divided into two groups; Group 1:  WOG system, Group 2: PTN. Baseline and post-operative CBCT scans were obtained for all the specimens using the same exposure parameters. The CT and CA of each root canal at 3, 6 and 9mm corresponding to coronal, middle and apical third were calculated. The data was analysed using SPSS; IBM version 23.0. The level of significance was kept at 0.05.

Results:

The WOG system exhibited significantly less CT at the level of 6mm compared with the PTN file (p<0.05). The intergroup comparison of CA revealed that WOG exhibited the greater centralization (0.616 ± 0.183) as compared to PTN (0.415 ± 0.433) at 9mm from the apex (p <0.05). However, both the systems revealed comparable outcomes in the apical third (p >0.05).

Conclusion:

WOG resulted in less canal transportation and more centralized preparations in the middle and coronal third of root canals with moderate degree of curvature. Besides, both the file systems observed acceptable range of deviations.

Keywords: Canal transportation, curved root canals, shaping ability, root canal preparation, micro-computed tomography

Introduction: This work aimed to examine the geometrical, metallurgical, and static mechanical properties of five reciprocating NiTi endodontic files with similar cross-sectional geometries. Materials and Methods: Reciproc Blue, ProDesign R, V File, V+ File, and Univy One systems were evaluated using a multimethod approach including geometrical analysis, scanning electron microscopy, energy-dispersive spectroscopy, differential scanning calorimetry, X-ray diffraction, bending resistance, and torsional tests. Results: R-phase was predominant in most instruments, while the Univy One system showed indications of a combined martensitic and R-phase structure. ProDesign R demonstrated superior flexibility, whereas Reciproc Blue and V File exhibited greater torsional resistance. Cross-sectional area was an important factor influencing the mechanical characteristics of the instruments, although metallurgical aspects appeared to influence the behavior of specific systems. Conclusion: Geometry and metallurgical characteristics influenced the observed static mechanical behavior of the evaluated reciprocating instruments. Instruments exhibiting higher proportions of martensite and R-phase demonstrated enhanced flexibility, while bending resistance was also strongly affected by cross-sectional geometry, highlighting the combined influence of material properties and design on mechanical performance. However, the findings should be interpreted within the limitations of static mechanical evaluation, since cyclic fatigue testing was not performed.

Introduction: The aim was to compare the cyclic fatigue resistance and the macroscopic, microscopic, and elemental characteristics of three reciprocating endodontic systems. Materials and Methods: An in vitro experimental study was conducted with 3 groups (n=20): WaveOne Gold (WOG), Roll Wave Blue (RWB), and TF4 Gold (TF4). Cyclic fatigue resistance was assessed using a custom device with artificial curved canals and an endodontic motor operating in reciprocating motion. The fracture time (FT), in seconds, and the number of cycles to fracture (NCF) were the parameters evaluated in this analysis. Macroscopic analysis was performed using macro photography to assess the pitch, its distribution along the instrument, and the cutting edges. Microscopic analysis was performed using scanning electron microscopy (SEM) to examine surface and cross-sectional features. Additionally, energy-dispersive X-ray spectroscopy (EDX) was used to determine the elemental composition. Data from the cyclic fatigue analysis were analyzed using the Kruskal–Wallis test and Dunn's post hoc test (α=0.05). Results: RWB showed the highest resistance to cyclic fatigue, with higher FT and NCF values. The pitch and its distribution differed among all groups. SEM analysis revealed a higher loss of cutting-edge sharpness on TF4 instruments and greater tip deformation on WOG when used. EDX analysis showed no significant differences in elemental composition among the systems. Conclusion: RWB demonstrated superior cyclic fatigue resistance. Additionally, the systems had similar chemical compositions but differed in performance, which could be associated with variations in their alloy characteristics, design, and heat treatment.

This case report presents the endodontic management of a hypertaurodontic mandibular second premolar with five root canals, a rare and complex anatomical variation. A 12-year-old male patient presented with a previously treated tooth (history of pulpotomy) with symptomatic apical periodontitis and necrotic pulp. Initial periapical radiographs suggested taurodontism, but cone‑beam computed tomography (CBCT) revealed the presence of five canals merging into four distinct apices. Under CBCT guidance, all canals were negotiated, cleaned, and shaped. An apical barrier was created with bioceramic material, followed by obturation using warm vertical condensation with resin‑based sealer. At the six‑month follow‑up, the tooth was asymptomatic and radiographically satisfactory. This case highlights the diagnostic indispensability of CBCT in detecting intricate root canal configurations in taurodontic teeth and outlines a structured clinical protocol for managing such challenging anatomies.

Tooth autotransplantation (TA) is indicated in cases of structurally compromised teeth with poor prognosis when a donor tooth is available. This case report describes the TA of a mandibular right third molar (48) into the position of the mandibular right second molar (47) in a 32-year-old male patient. Clinically, extensive coronal destruction and a sinus tract were observed in tooth 47, rendering retreatment unfavorable. The tooth was diagnosed as previously treated, with a chronic apical abscess. Therefore, tooth 48 was autotransplanted into the 47 position. Four months later, apical external inflammatory root resorption was observed. However, root canal treatment was performed one year after TA because the patient did not adhere to follow-up recommendations. After two years, the tooth remained asymptomatic, with no signs of periapical lesions or periodontal changes. In conclusion, TA may serve as a viable strategy for replacing structurally compromised permanent molars, thereby preserving the function of the natural dentition.

Introduction: The close relationship between pulp stones in the pulp chamber and pulp neurovascular tissues suggests that the presence of pulp stones may compromise successful anesthesia. The present study assessed the effect of pulp stone presence on the failure of anesthesia in mandibular and maxillary molars. Materials & Methods: In this retrospective cohort study, 126 patients were studied. Pulp stones were diagnosed by periapical radiography. After the anesthetic agent injection, failure was defined as patients raising their hand upon experiencing pain during any procedural step of endodontic treatment. Furthermore, sound, eye, and motor (SEM) measures were used to assess the pain experience. In the case of either pain felt or the patients’ demand, supplementary injections were made using the intraligamental technique.  Multivariate logistic regression analysis was used to assess the effects of different variables on the success of anesthesia. Results: The overall prevalence of pulp stones in the patients was 59.5%, with 42.9% and 57.1% for males and females, respectively. The incidence of pulp stones in patients under the age of 40 was 54.7%, whereas in the ≥40 age group, it was 64.5%. The highest incidences of pulp stones were reported for maxillary second (42.9%) and first (21.4%) molars, followed by mandibular second (18.6%) and first molars (17.1%). Overall, the success rate of anesthesia was 55.6% for treated teeth. However, no significant differences were observed in the success rate of anesthesia regarding gender, tooth type, and pulp stone presence. Only the age group of patients significantly predicted the success of anesthesia (Odds ratio: 1.135; CI 95%: 1.43-6.76; P=0.004). Conclusion: Pulp stones had no significant effect on the success of anesthesia in mandibular and maxillary molars.

Introduction: To compare the cyclic fatigue resistance of three rotary glide-path file systems (ProGlider, Px-One, and Pro-path) in simulated canals with double curvature. Materials and Methods: A total of 78 new files (n=26 per system) were evaluated and divided into six groups according to canal curvature (30^° and 60^°). Artificial stainless-steel canals (19 mm long, 8 mm curvature radius) were used. All files were operated at 300 rpm and 2.0 Ncm torque using continuous rotation at room temperature (22±2 ^°C). Cyclic fatigue resistance was assessed by recording the time to fracture. Shapiro-Wilk and Levene’s tests were performed to evaluate normality and homogeneity of variance, respectively. Data were analyzed using Welch’s ANOVA and Games-Howell post hoc test (P<0.05). Results: The Pro-path system showed significantly greater fatigue resistance than Px-One and ProGlider at both 30^° and 60^° canal curvatures (P<0.001). In 30^° canals, Pro-path exhibited a mean fracture time of 76.42±12.50 min, compared to 57.41±11.77 min for ProGlider and 49.84±14.77 min for Px-One. In 60^° canals, Pro-path again demonstrated superior performance (18.90±4.86 min), followed by ProGlider (5.71±1.23 min) and Px-One (4.70±1.20 min). Conclusions: Under these experimental conditions, Pro-path demonstrated significantly greater cyclic fatigue resistance than ProGlider and Px-One in double-curvature simulated canals. However, the absence of body temperature control and a static testing model limits clinical extrapolation. Further studies validating these findings under physiological conditions and dynamic kinematics are warranted.

Introduction: Root canal therapy is an essential part of dental care that has a high success rate, as reported under controlled conditions. Nevertheless, procedural errors can be present when conducted by undergraduate students and have a detrimental impact on treatment outcomes. To better endodontic education and clinical performance, the frequency and types of iatrogenic errors should be evaluated. The study aimed to determine the prevalence and the nature of iatrogenic errors during root canal treatments that are administered by undergraduate dental students in their fifth year. Materials and Methods: One hundred and twenty-five endodontically treated teeth were chosen randomly. The fifth-year dental students performed all the treatments using a standardized endodontic protocol. Preoperative, intraoperative, and postoperative radiographs were assessed to find out iatrogenic errors, such as ledge, perforation, canal obstruction, separation of instruments, overfilling, underfilling, and voids. This descriptive study reports the frequency of errors without inferential statistical analysis. Results: Radiographic evaluation indicated that at least one of the iatrogenic errors during treatment was observed in 32.8% of the treated cases. The most common mistake was obturation voids, which were identified 11.2% of the total cases and were found mostly in the second premolars. Conclusion: Root canal treatments that were carried out by undergraduates had a relatively high number of iatrogenic errors, with obturation errors being the most frequent. These results lead to the necessity of more effective clinical training, better supervision, and integration of more sophisticated endodontic procedures to minimize errors in the course of the procedure and enhance the quality of the treatment.

Introduction: To systematically evaluate and compare the in vitro cytotoxic effects of three calcium silicate-based cements [Mineral Trioxide Aggregate (MTA), Biodentine, and Calcium Enriched Mixture (CEM) Cement], focusing on their biocompatibility with human dental pulp cells in vital pulp therapy (VPT). Materials and Methods: A comprehensive search was conducted in PubMed, Scopus, Web of Science, Cochrane, ProQuest, Wiley, and Ovid (including Embase) for in vitro studies published up to February 2023. Studies evaluating cytotoxicity via cell viability assays (e.g., MTT) were included. Results: Among 8,004 screened records, 32 studies met the inclusion criteria, with 11 included in the meta-analysis. Overall, no significant differences in cytotoxicity were identified among Mineral Trioxide Aggregate (MTA), Biodentine, and Calcium-Enriched Mixture (CEM) cement. Nevertheless, undiluted MTA and Biodentine at a 1:4 dilution were associated with a statistically significant reduction in cell viability at 48 hours (P<0.05). No other concentrations or exposure durations showed significant cytotoxic effects. CEM cement consistently demonstrated favorable biocompatibility across the included studies. Conclusion: These findings indicate that MTA, Biodentine, and CEM cement generally exhibit acceptable in vitro biocompatibility for vital pulp therapy.  Their biological responses may be influenced by material concentration and exposure duration, emphasizing the importance of careful and controlled clinical application.

Introduction:
Successful management of apical periodontitis relies on effective root canal obturation to eliminate microbial activity and promote periapical healing. Bioceramic sealers have emerged as promising alternatives to conventional sealers, offering superior biocompatibility and regenerative potential. However, their comparative clinical efficacy and safety remain uncertain.

Materials and Methods:
This systematic review evaluated the effectiveness and safety of bioceramic sealer-assisted obturation compared with conventional sealer methods in the treatment of apical periodontitis. A comprehensive search was performed in PubMed, Scopus, Web of Science, and Embase following PRISMA 2020 guidelines. Randomized controlled trials comparing bioceramic and conventional sealers were included. Three independent reviewers conducted study selection, data extraction, and risk of bias assessment using the RoB 2.0 tool. Primary outcomes were apical healing and postoperative pain; secondary outcomes included adverse events and procedural complications.

Results:
From 491 identified records, 12 randomized controlled trials met the inclusion criteria.  

Meta-analysis of four trials revealed no statistically significant difference in healing rates between bioceramic and conventional sealers (RR = 1.05, 95% CI 0.89–1.23, p = 0.61; I² = 0%). No major adverse events were reported. Bioceramic sealers showed comparable or superior results in apical healing and postoperative pain reduction, particularly in cases with extensive periapical lesions. No serious adverse events were reported. Methodological variability and differences in sealer composition limited interstudy comparability.

Conclusion:
Bioceramic sealers may offer clinical advantages over conventional sealers by enhancing periapical healing and minimizing postoperative discomfort. Nevertheless, further high-quality trials with standardized protocols are necessary to confirm these findings.

Keywords: Apical Periodontitis, Postoperative Pain, Standard Sealers.

Traumatic dental injuries (TDIs) involving both tooth avulsion and alveolar fracture present significant clinical challenges, particularly in growing patients, where long-term restorative planning must accommodate ongoing craniofacial development. This report describes the multidisciplinary management of an 11-year-old boy who sustained avulsion of tooth #21 and an associated alveolar fracture following a sports-related injury. Clinical and cone-beam computed tomography evaluations revealed an alveolar segment fracture extending from teeth #12 to #21. The displaced segment was manually repositioned and stabilized using a flexible composite and wire splint. Subsequent loss of pulpal vitality in teeth #11 and #12 was managed by root canal treatment with interim calcium hydroxide therapy. Given the patient’s incomplete skeletal growth, a minimally invasive Maryland bridge was selected to replace the missing tooth #21. Clinical and radiographic follow-up at 6 and 12 months demonstrated normal healing of the alveolar bone and periodontal structures, with no evidence of root resorption or ankylosis. Successful management of complex dentoalveolar trauma in growing patients requires early diagnosis, appropriate splinting, endodontic intervention when indicated, and growth-conscious prosthetic rehabilitation. Long-term follow-up is essential to monitor healing and plan future definitive treatment.

The aim was to identify and analyse publication trends, bibliometric indicators, and research characteristics of artificial intelligence studies published in Endodontic journals. An advanced search was performed in “Web of Science All Databases” and “Scopus” employing the keywords “Endodontics”, “Endodontic”, “Artificial Intelligence”, and “AI”. Articles published in journals containing the terms “Endodontic”, “Endodontics”, or “Endodontology” were included. A total of 214 authors contributed to the 48 analyzed studies. Mohammad‑Rahimi, H., and Nosrat, A., were the most productive authors. The United States contributed the highest number of publications. The Journal of Endodontics was the primary outlet. Publications increased sharply between 2024 and 2025. Basic research predominated, with radiology as the dominant study field. Deep learning was the most frequently used AI methodology, particularly convolutional neural networks for radiographic diagnosis and segmentation. AI research in endodontics has expanded markedly in recent years, driven predominantly by advances in deep learning and imaging analysis.

Introduction: The present study aims to evaluate the root canal morphology of permanent lower incisors by cone-beam computed tomography (CBCT) according to Vertucci’s classification (1984), and to correlate the findings with sex, age group, and side of the dental arch. Materials and Methods:  This was a descriptive observational study that used a sample of mandibular CBCT scans performed between 2021 and 2024 at a private dental radiology service. When none of the Vertucci configurations was applicable, type 0 was assigned. Results: Type I was the predominant morphological configuration, followed by type III, for all variables analyzed. Regarding sex, type I was more common among females (71.1%), while type III accounted for 21.2% in both males and females. With respect to age, type I was more common among minors (76.8%), and type III among older adults (23.3%). The type I configuration was more frequently observed on the right side of the dental arch (70.3%), and type III on the left side (21.9%). Conclusion: The anatomical observations of the lower incisors highlight the need for careful analysis of their internal morphology during endodontic treatment.

Introduction: Achieving a three-dimensional seal in the apical, lateral, and coronal regions of the root canal is a key objective in endodontic treatment. This study aimed to compare the apical sealing ability of NeoSealer Flo, MTA-Fillapex, and AH-26 over different time intervals using the fluid filtration method. Materials and Methods: In this in vitro study, 58 single-rooted premolars (n=18 per group; 2 positive and 2 negative controls) were selected and prepared using the ProTaper system up to file F3. Canals were obturated with the single-cone technique using one of the three tested sealers. Apical microleakage was measured at 24 hours, 1 week, and 4 weeks using the fluid filtration method. Data were analyzed using one-way ANOVA, repeated measures ANOVA, ANCOVA, and Tukey’s HSD post hoc test (P<0.05). Results: The results indicated that sealer type, time, and their interaction had a statistically significant effect on apical microleakage (P<0.001). NeoSealer Flo showed the lowest and AH-26 the highest leakage values across all time intervals. In all three groups, microleakage decreased over time. This reduction was statistically significant from 24 hours to 1 week in the NeoSealer Flo and MTA-Fillapex groups (P<0.001), and from 1 week to 4 weeks in the AH-26 group (P<0.05). Conclusion: Within the limitations of this study, NeoSealer Flo demonstrated superior apical sealing ability at all time points. Under single-cone obturation conditions, bioceramic sealers such as NeoSealer Flo may provide more predictable long-term apical sealing compared to resin-based alternatives.

Maxillary central incisors typically exhibit a single root and canal. The presence of two roots with separate canals, as defined by Vertucci’s type V morphology, is extremely rare and presents diagnostic and technical challenges for nonsurgical endodontic treatment. This report describes the endodontic management of a maxillary right central incisor (tooth #11) exhibiting a sinus tract, negative responses to pulp sensibility tests, and radiographic evidence of apical periodontitis in a 24-year-old female patient. Cone-beam computed tomography (CBCT) revealed a two-rooted anatomy with independent canals splitting at the middle third. Under magnification, access was refined using ultrasonic tips. The palatal root canal was prepared with NiTi CM rotary files, while the wider buccal canal was instrumented with stainless steel K-files. Both canals were disinfected using passive ultrasonic irrigation with 2.5% sodium hypochlorite and 17% EDTA, followed by intracanal calcium hydroxide medication. Obturation was completed using the single-cone technique with a bioceramic sealer. Radiographic follow-up at 14 and 57 months confirmed complete periapical healing and absence of symptoms, demonstrating long-term clinical success. Atypical root canal anatomy in maxillary incisors necessitates advanced imaging/magnification. The use of CBCT, NiTi CM files, and bioceramic sealers enabled accurate diagnosis, conservative canal shaping, and a successful long-term outcome in this rare morphology case.

Tooth avulsion represents a severe dental injury, and prognosis depends on extra‑oral time and storage. Its major complications include ankylosis and external inflammatory root resorption. We report a 14-year-old female who presented with pain in her upper incisors one year after avulsion of teeth 11 and 21, replanted after 60 minutes in dry cloth and splinted for four months without follow-up. Clinical and radiographic examinations were consistent with severe external inflammatory root resorption in the teeth #11, 12, 21, and 22. Given her age and unsuitability for implants, staged endodontic therapy was performed over four months. Canals were prepared under rubber dam isolation, irrigated with 17% EDTA and 5.25% sodium hypochlorite with ultrasonic activation, and dressed with non-setting calcium hydroxide. Dressing was refreshed at sequential visits until resorption stabilized. Final obturation used calcium-enriched mixture (CEM) cement at perforations and gutta-percha in remaining canal spaces, and AH-26 sealer was used as sealant. Our treatment arrested resorption and preserved function, though the long-term risk of ankylosis remains high. This case report underscores the need for immediate replantation, physiologic storage media, and timely endodontic intervention to mitigate complications. Close monitoring remains vital for maintaining aesthetics and function in growing patients.

Introduction: This study aimed to evaluate the bond strength of a bioceramic endodontic sealer and AH-Plus sealer irrigated with 2% chlorhexidine (CHX), compared to irrigation with 2.5% sodium hypochlorite (NaOCl) as a control group. Materials and Methods: Thirty freshly extracted single-rooted human teeth were prepared using reciprocating R25 and R40 files. Irrigation consisted of 2.5% NaOCl in the control group and 2% CHX gel in the experimental group, with additional irrigation using saline solution after each instrument change. Samples were divided into four groups: two with CHX, one with bioceramic sealer, and the other with AH-Plus sealer, and two with hypochlorite, one with bioceramic sealer and the other with AH-Plus sealer. The teeth were sectioned, and the resulting slices were subjected to the push-out test using a mechanical testing machine for measuring the microtensile force. After testing, samples were examined to determine the failure pattern. Data normality was assessed (Shapiro-Wilk, P<0.05), and non-parametric analyses (Kruskal-Wallis with Dunn’s post hoc, Wilcoxon rank-sum with Benjamini-Hochberg correction) were applied. Effect sizes (Cohen’s d, Cliff’s Delta), bootstrap 95% confidence intervals (CIs) (2000 replicates), and the post hoc power were calculated. Significance was set at P<0.05. Results: AH-Plus exhibited higher bond strength than Sealer Plus BC across all root thirds, independent of irrigant. For Sealer Plus BC, bond strength was influenced by irrigant, with NaOCl producing higher values than CHX (P<0.05). Conclusion: AH-Plus exhibited superior bond strength irrespective of the irrigant used. In contrast, the bond strength of the Sealer Plus bioceramic sealer was influenced by the irrigant, with NaOCl yielding higher values than CHX.

Introduction: Bioceramic materials are integral to regenerative endodontics, yet comparative data on their osteogenic potential remain limited. This study compared the osteogenic potential of four bioceramics: hydroxyapatite (HA), a nano-hydroxyapatite/chitosan composite (n-HA/CSS), Angelus mineral trioxide aggregate (MTA), and calcium-enriched mixture (CEM) cement. Materials and Methods: Human osteoblast-like Saos-2 cells were exposed to materials via direct contact and extract models. Cell viability and proliferation were assessed using the MTT assay, attachment and morphology were examined by scanning electron microscopy (SEM), and osteogenic differentiation was evaluated by real-time PCR for alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC) at 3 and 6 days. Results: All materials were non-cytotoxic. In direct culture, CEM significantly enhanced cell proliferation by day 3 (~3-fold, P<0.001). SEM revealed superior cell attachment and extracellular matrix secretion on n-HA/CS and CEM surfaces. Gene expression analysis demonstrated that CEM robustly upregulated ALP (~12-fold vs. control, P<0.001), a level 6-fold higher than MTA (P<0.05). Furthermore, both CEM and n-HA/CS promoted pronounced expression of the late markers BSP (~5-fold, P<0.001) and OC (10-fold and 12-fold, P<0.001 and P<0.001, respectively). MTA consistently elicited the lowest osteogenic response. Conclusions: CEM and the n-HA/CS were identified as the strongest promoters of osteoblast proliferation and differentiation, indicating their superior bioactivity over MTA and HA and their potential for endodontic and surgical hard tissue regeneration.

Magnesium phosphate cements (MPCs) have recently gained attention as potential materials for endodontic applications due to their rapid setting, favourable mechanical properties, and bioactive potential. Laboratory and preclinical studies indicate that MPCs can form apatite-like structures, exhibit good compressive strength, and support cell viability, suggesting promising biological interactions. However, several limitations remain unresolved. The acid–base setting reaction of MPCs is strongly exothermic, which may pose a risk to pulp or periapical tissues, and ammonium-containing formulations can release cytotoxic ammonia, although partial mitigation is possible through sodium phosphate substitution. Rapid setting enhances handling in controlled conditions but may complicate placement in complex root canal anatomies. While in vitro studies suggest comparable or superior sealing ability relative to conventional calcium silicate cements, human clinical evidence is minimal or absent. Degradation and resorption profiles of MPCs may further affect their suitability as scaffolds in regenerative endodontics. Overall, MPCs represent promising investigational materials, yet claims regarding clinical readiness are premature. Careful evaluation of their physicochemical behaviour, biological safety, and practical handling is essential before consideration for routine clinical use.