Clinical and experimental dental researchPetra Dijanic, Marko Katic, Ivan Tomasic, Ana Ivanisevic, Jurica Matijevic
OBJECTIVE: To evaluate the dimensional stability of root canal obturation materials under dynamic conditions by simulating ageing. MATERIALS AND METHODS: Forty extracted, single-rooted, human teeth were decoronated and randomly assigned to four experimental groups of 10 teeth each. Root canals were instrumented using the Reciproc R40 system and obturated using the single-cone technique in combination with one of four sealers: AH Plus, MTA Fillapex, TotalFill BC Sealer, or EndoREZ. All specimens underwent thermal cycling (9000 cycles between 5°C and 55°C) to simulate ageing. Each tooth was scanned using high-resolution micro-computed tomography (micro-CT) before and after thermal cycling. Volumetric changes of the filling materials were compared by analyzing the pre- and post-treatment scans in the apical 1 and 2-mm, and over the total canal volume. RESULTS: At the apical 1-mm region, AH Plus exhibited the greatest expansion ( 0.016 mm 3 $0.016\,{\mathrm{mm}}^{3}$ ). EndoREZ, MTA Fillapex, and TotalFill BC Sealer showed significantly lower expansion ( 0.008 , 0.003 , 0.001 mm 3 $0.008,0.003,0.001\,{\mathrm{mm}}^{3}$ ) than AH Plus. In the apical 2-mm region, only TotalFill BC Sealer expanded significantly less than AH Plus, with a difference of 0.03 mm3. CONCLUSION: Thermal cycling induced measurable expansion in all tested endodontic sealers, with the most pronounced effects observed in the apical region. AH Plus exhibited significantly greater expansion than the other materials. Controlled apical expansion may be clinically beneficial by improving sealer adaptation to dentinal walls and enhancing apical sealing without generating detrimental radial stresses. These findings underscore the clinical relevance of long-term volumetric stability under thermally dynamic conditions and suggest that sealer selection may influence the durability of the apical seal.
BMC oral healthKhaled A Ghozi, Mohamed A Gomaa, Amany E Badr
BACKGROUND: The present study aimed to evaluate the impact of intracanal medicaments-calcium hydroxide (CH) and calcium hydroxide/nano-chitosan (CH/NC)-on the push-out bond strength (POBS) of AH Plus (AHP) and NeoSEALER Flo (NSF). METHODS: Nano-chitosan (NC) characterization was done using transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential analysis. Sixty extracted maxillary central incisors were instrumented up to X5 (50/0.06). Based on intracanal medicament used, specimens were allocated into three groups (n = 20): Group I; no intracanal medicament (control), Group II; (CH), and Group III; (CH/NC). Intracanal medicaments were removed after one week of incubation. Each group was subdivided based on sealer used (n = 10): subgroup A (AHP) and subgroup B (NSF). Obturation was performed with cold lateral compaction. After one week of incubation, roots were sectioned and a universal testing machine was used to evaluate POBS. Three-way ANOVA and Chi-square tests were conducted at 0.05 significance level. RESULTS: TEM showed mostly spherical NC particles with diameters less than 50 nm. DLS analysis revealed a hydrodynamic Z-average diameter of 62.4 nm with a polydispersity index of 0.195. Zeta potential analysis demonstrated a positive surface charge of + 47.57 mV. The "medication" factor, "medication/sealer", "medication/root level" and "sealer/root level" interactions significantly affected POBS (P < 0.05). Neither "sealer" nor "root level" factors significantly affected POBS (P > 0.05). Pooled POBS data revealed that: IA and IB subgroups were significantly higher than IIA, IIB, IIIA and IIIB subgroups (P < 0.05). Regarding failure mode, tested subgroups showed no significant difference (P > 0.05). CONCLUSIONS: Under the conditions of this study, prior application of CH or CH/NC reduced POBS for both sealers compared with controls. The addition of NC to CH did not provide a statistically significant improvement in POBS compared to CH alone. Overall, AHP and NSF demonstrated comparable POBS to root canal dentin.
PloS oneMevlüt Sinan Ocak, Mehmet Eskibağlar, Mustafa Gündoğar
This study evaluated the comparative performance of different root canal obturation approaches using different sealing materials on the push-out bond strength of dentin samples obtained from patients with diabetes mellitus (DM). Forty single-rooted mandibular premolars were instrumented using the Reciproc R40 system and randomly assigned to four groups (n = 10 teeth each): (1) cold lateral compaction with AH Plus, (2) warm vertical compaction with AH Plus, (3) hydraulic single-cone obturation with gutta-percha and Bioserra sealer, and (4) sealer-only technique using the Bioserra bioceramic sealer. After storage at 37°C and 100% humidity for one week, 1-mm slices were prepared from the coronal, middle, and apical thirds and subjected to push-out testing. Data were analyzed using ANOVA and Tukey's test (p < 0.05). Significant differences in push-out bond strength were observed among the obturation approaches using different sealer materials (p < 0.05). Bioceramic sealers exhibited higher bond strengths than epoxy resin-based sealers, particularly in the middle and apical thirds. Hydraulic single-cone and bioceramic sealer-only approaches outperformed conventional techniques (p < 0.001), whereas no significant difference was observed between cold lateral and warm vertical compaction techniques. Obturation approaches employing bioceramic sealers demonstrated superior bonding in diabetic dentin, suggesting potential advantages over conventional methods in the context of diabetic dentin.
BMC oral healthSeren Kaya, Özlem Beren Satılmış, Ayşe Işıl Cihan, Firdevs Tulga Öz
BACKGROUND: Vital pulp therapies are treatment approaches that preserve the health and function of the primary tooth pulp. This study aimed to evaluate the clinical and radiographic outcomes of indirect pulp treatment (IPT) and direct pulp capping (DPC) performed with MTA in deeply carious primary second molars. METHODS: This clinical outcome study evaluated IPT (n = 30) and DPC (n = 30) treatments using MTA in 60 deeply carious second primary molars. Clinical and radiographic assessments were conducted at 6 and 12 months to determine treatment success based on predefined criteria. Categorical variables for both treatment groups were analyzed using Fisher's exact test. A p-value < 0.05 was considered statistically significant. RESULTS: The overall success rate of the IPT group was 96.55%, with clinical and radiographic success rates of 96.67% at 6 months and 100% at 12 months. In the DPC group, the overall success rate was 86.21%, showing clinical success of 96.67% and radiographic success of 90% at the 6-month follow-up, and both clinical and radiographic success rates of 96.15% at the 12-month follow-up. Despite these numerical differences, no statistically significant difference was found between the treatment outcomes (p = 0.352). CONCLUSIONS: IPT and DPC treatments using MTA demonstrated high clinical and radiographic success in primary molars over the 12-month follow-up period. Under appropriate clinical conditions, including proper case selection, appropriate material selection, and meticulous technique, IPT and DPC can be considered successful conservative treatments. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT07382115, registered on 26 January 2026, retrospectively registered.
Scientific reportsShaimaa S El-Desouky, Rehab F Ghouraba, Ibrahim A Kabbash, Nancy M Metwally
Eggshell powder (EP) has been suggested as a cost-effective pulpotomy material due to its high biocompatibility, remineralization potential, and ability to induce dentin bridge formation. This study compared the clinical and radiographic outcomes of EP, Biodentine, and mineral trioxide aggregate (MTA) when used as pulpotomy agents in primary molars. A randomized split-mouth clinical trial was performed on 30 children, each receiving pulpotomy in 3 primary molars assigned to Group I (EP), Group II (Biodentine), and Group III (MTA), with 30 teeth per group. Clinical evaluations were carried out at baseline, 3-, 6-, and 12-month. Cone-beam computed tomography (CBCT) scans were performed immediately postoperatively and at 12- month to evaluate root resorption and radiodensity changes. All groups demonstrated 100% clinical success within 3-month. At 12-month, Group I showed significantly higher rates of spontaneous pain, abnormal mobility, fistula, and internal and external root resorption (p < .05). CBCT analysis revealed significantly lower radiodensity values in Group I compared with Groups II and III. Group III (MTA) exhibited the most favorable radiographic outcomes, followed by Group II (Biodentine). EP achieved acceptable short-term results; however, its long-term performance was inferior to MTA and Biodentine.Clinical significance EP represents a low-cost, biocompatible, and environmentally sustainable biomaterial derived from recycled natural waste. Despite its eco-friendly and biomimetic advantages, its long-term clinical and radiographic performance remained inferior to Biodentine and MTA, which continue to be the more reliable pulpotomy materials for primary molars.Trial registration NCT05812053, "ComparativeEvaluation of Eggshell Powder in Primary Teeth Pulpotomy", https://clinicaltrials.gov/ . Registered: 2023/04/13.
BMC oral healthFatma M Abu Naeem, Shaimaa Ibrahim Bakry, Ahmed S ElSheshtawy, Ahmed Abdou, Hajer M Abd ElHamid
BACKGROUND: The structural integrity of teeth after endodontic retreatment depends on the amount of remaining dentin. Excessive instrumentation can weaken roots and predispose them to fracture. This study evaluated the fracture resistance of maxillary premolars following non-surgical retreatment (NS-ReT) with Retreaty and XP-endo Rise systems. MATERIALS AND METHODS: Forty-eight maxillary first premolar roots were randomly assigned to 4 groups (n = 12); G1-NC (Negative control, non-instrumented), G2-PC (Positive control, instrumented, not obturated), G3-RETY (Retreaty), and G4-XPER (XP-endo Rise). G2, G3 and G4 groups were prepared using the iRace system. Groups G3 and G4 were obturated with gutta-percha and resin sealer. Gutta percha removal was performed using Retreaty (G3-RETY) and XP-endo Rise retreatment files (G4-XPER). All samples were subjected to fracture testing using a universal testing machine & the maximum fracture load (N) was recorded. Gutta percha removal times (Tf) and total time of retreatment were also measured. Statistical analysis was performed using a mixed-model analysis of variance (ANOVA) (α = 0.05). RESULTS: The fracture resistance of G1-NC (942.92 ± 24.73 N) had significantly higher values compared to all other groups. Fracture values for the G2-PC (829.62 ± 71.55 N) and the G3-RETY (818.29 ± 73.14 N) did not significantly differ from each other (p = 1.000), but both were significantly higher than the G4-XPER (489.37 ± 33.47 N). The total time of retreatment was significantly reduced when using the G3-RETY (3.89 ± 0.84 min) compared to the G4-XPER (13.30 ± 2.05 min), p < .001. CONCLUSIONS: Teeth retreated using the Retreaty instruments demonstrated superior fracture resistance compared to XP-endo Rise and their values were comparable to the positive control group. Moreover, Retreaty file system showed faster gutta-percha removal and canal preparation during retreatments.
Lasers in medical scienceOlcay Özdemir, Mustafa Gündoğar, Taha Özyürek, Nergiz Bolat, Özgecan Gündoğar, Sena Kaşıkçı, Markus Haapasalo
This study aimed to evaluate the effectiveness of energy-intensive irrigation activation systems for removing residual pulp tissue in completely uninstrumented oval root canals with different access cavity designs, using histological analysis. Seventy extracted human mandibular premolars with oval root canal morphology and organic tissue remnants were randomly assigned to five irrigation protocols: syringe-needle irrigation (control), Er: YAG laser (SWEEPS, Fotona), Er, Cr: YSGG laser (Waterlase iPlus, Biolase), multisonic high-speed irrigation (GentleWave G4 with ProControl, SonEndo, 5-min protocol), and an extended multisonic protocol (9-min). Each group was further divided according to access cavity design into ultra-conservative and traditional cavities (n = 7). Following irrigation with sodium hypochlorite and EDTA, serial histological sections from the apical third were prepared, and the percentage of residual pulp tissue was quantified using ImageJ software. Data were analyzed using two-way ANOVA with Bonferroni multiple comparisons (p < 0.05). The irrigation activation system significantly affected residual tissue percentages (p < 0.001; η²=0.736), whereas access cavity design showed no significant effect (p = 0.965). Syringe-needle irrigation demonstrated the highest residual tissue values (≈ 20%). Both laser activation systems significantly reduced residual tissue compared with needle irrigation but showed comparable performance (≈ 4-6%). Multisonic high-speed irrigation further improved canal cleanliness, with the 5-min protocol showing lower residual tissue values (≈ 2%), and the extended 9-min protocol achieving the lowest percentages (< 1%), approaching near-complete debridement. Within the limitations of this in vitro histological study, energy-intensive irrigation systems significantly improved the removal of residual pulp tissue in uninstrumented oval root canals. The extended multisonic irrigation protocol demonstrated the highest debridement efficiency under the tested conditions. These findings may inform future minimally invasive endodontic strategies; however, they should not be interpreted as supporting the clinical replacement of mechanical instrumentation.
Clinical oral investigationsTobias Zeller, Emilio Couso-Queiruga, Simone F M Janner, Michael M Bornstein, Valerie G A Suter, Vivianne Chappuis, Clemens Raabe
OBJECTIVES: To compare the survival and success rates of autotransplanted immature teeth versus mature teeth treated with extraoral root-end resection (EORER), and assess inter-rater agreement in radiographic evaluation between oral surgeons (OS) and general practitioners (GPs). MATERIALS AND METHODS: Patients who underwent autotransplantation between 2000 and 2022 were retrospectively identified and invited for clinical and radiographic follow-up examinations. Periapical radiographs were independently evaluated by three OS and three GPs. Predictors of survival and success were analyzed using univariate generalized estimating equation models. RESULTS: Fifty-eight autotransplanted teeth (39 immature, 19 mature) in 50 patients were included. Immature transplants showed higher survival (89.7% vs. 73.7%; mean follow-up 8.4 vs. 5.6 years) and higher success rates (63.3% vs. 31.3%) than EORER-treated mature transplants. Pulp revascularization was observed in 88.5% of immature and 54.5% of EORER-treated mature teeth. Longer splinting and pristine recipient sites were associated with higher survival; premolar and molar sites with higher success (p ≤ 0.047). Inter-rater agreement was lowest for pulp canal obliteration, with OS showing higher agreement than GPs (p = 0.02). GPs generally reported more pathological findings on the radiographs. CONCLUSIONS: Immature transplants demonstrated higher survival and success rates than EORER-treated mature transplants. However, pulp revascularization was observed in over half of mature transplants. Radiographic assessment varied considerably between OS and GPs. CLINICAL RELEVANCE: Immature donor teeth remain the preferred option for autotransplantation. Nevertheless, EORER extends eligibility to mature donor teeth by promoting pulp revascularization, potentially avoiding root canal treatment. Standardized radiographic criteria and calibration are warranted for follow-up over time.
This study reports a case of complicated crown-root fractures of the maxillary central incisors (teeth 8 and 9) in a 10-year-old boy. Vital pulpotomy and iRoot BP Plus capping were performed to protect the pulp. The fractured crown fragments were used to restore the tooth morphology, and the esthetics and function of both central incisors were restored. The roots of the affected teeth continued to develop normally. Twenty-five months after the initial treatment, the patient suffered another trauma, resulting in a second dislodgement of the fractured crown of the left maxillary central incisor. Given the structural integrity of the fractured crown, reattachment was performed again to reshape the tooth, thereby restoring its appearance to the greatest extent possible. After a 40-month follow-up, the esthetics and function of teeth 8 and 9 remained satisfactory. Normal anterior occlusion was established, and the treatment outcome was highly appreciated by the patient and his parents. This case provides clinical detail useful for managing complex crown and root fractures caused by multiple traumas in young permanent teeth, emphasizing the importance of pulp preservation, conservative restoration, and preventive measures.
Acta odontologica ScandinavicaViktorija Ašmankevičiūtė-Lemisnkė, Gediminas Žekonis
OBJECTIVE: The objective of this study was to compare self-reported treatment preferences related to pulpectomy prior to prosthetic treatment, restoration selection for vital teeth, and impression-taking methods between Lithuanian general dentists (GDs) and prosthodontists (Ps). MATERIAL AND METHODS: A questionnaire-based survey was conducted among 386 dentists in Lithuania, including GDs (62.4%) and Ps (37.6%). Data were analyzed using descriptive statistics and inferential tests (Chi-square and Fisher's exact test), with a significance level of p < 0.05. RESULTS: Most indications for pulpectomy were reported similarly by both groups; however, significant differences were observed for extensive coronal structure loss (> 50%) and deep caries, cervical lesions, gingival recession, short clinical crown, insufficient retention, enamel hypoplasia, and external root resorption (p < 0.05). Ps also more frequently reported using indirect restorations, including porcelain-fused-to-metal crowns, lithium disilicate ceramic inlays and onlays, and polymethyl methacrylate crowns. Conventional impressions were more common among GDs, whereas digital or combined workflows were more common among Ps. CONCLUSIONS: Lithuanian GDs and Ps reported broadly similar preferences regarding preservation of tooth vitality, but differed in selected pulpectomy indications, restorative options, and impression-taking methods. These differences may reflect variation in specialist training, clinical experience, and access to prosthetic workflows.
JPMA. The Journal of the Pakistan Medical AssociationSoha Pirzado, Syed Yawar Ali Abidi, Maham Muneeb Lone, Samira Adnan
OBJECTIVE: To evaluate and compare the effectiveness of two advanced rotary endodontic file systems using orange oil in removing obturation material from root canals.s. METHODS: The experimental in-vitro study was conducted at the Department of Operative Dentistry and Endodontics, Sindh Institute of Oral Health Sciences, Jinnah Sindh Medical University, Karachi, from December 7, 2023, to May 31, 2024, and comprised extracted, single-rooted teeth with straight canals that were cleaned, prepared, obturated and then randomised into ProTaper Gold Group A and WaveOne Gold group B. Variables examined and recorded were length of remaining gutta-percha in canal (mm), gutta-percha extrusion through apex (yes/no) and time taken for gutta-percha removal. Data was analysed using SPSS 23.. RESULTS: Of the 32 teeth, 16(50%) were in each of the two groups. All the 32(100%) teeth showed some residual obturation material within the canal. The amount of root filling remaining was significantly reduced in Group B compared to Group A (p=0.007). CONCLUSION: The mean gutta percha removal from root canals when using WaveOne Gold files was significantly better compared to the use of ProTaper Gold files. WaveOne Gold files also showed minimal extrusion, and took less time for gutta percha removal from root canal spaces.
The Libyan journal of medicineAli Robaian AlQahtani
Fractured instrument retrieval remains one of the most challenging aspects of endodontics, with reported incidence rates ranging from 0.3% to 12%. This complication is particularly common with nickel‒titanium (NiTi) rotary files used in curved canals. Instrument separation hinders effective canal disinfection, compromises the quality of obturation, and may necessitate additional interventions such as bypassing, retrieval, or surgical management. Conventional retrieval techniques often lead to dentin loss, compromising root structure. The use of dental operating microscopes and their integration with ultrasonic troughs, microtubes, and specialized retrieval kits, including loop devices, has significantly enhanced the predictability of retrieval procedures while minimizing the loss of tooth structure. However, the effectiveness of these methods remains highly dependent on operator skill. Numerous innovations are continually emerging to facilitate retrieval, with recent attention on magnetic fields. Studies on such emerging devices utilizing magnetic and electromagnetic attraction have introduced a promising new direction for further exploration. This review aims to provide a comprehensive, evidence-based perspective to guide clinical decision-making and keep practitioners updated about the latest advancements in minimally invasive retrieval techniques in endodontic practice.
Scientific reportsThomas Gerhard Wolf, Janika Wollmann, James Deschner
This retrospective matched case-control study aimed to identify potential risk factors associated with the development of dental abscesses during or after endodontic treatment. The study analyzed data from 133 patients (74 males, 58 females; mean age 43.1 ± 16.5 years) with abscess formation of endodontic origin and compared them with a 1:1 matched control group without abscess. Matching was performed based on age and the specifically treated tooth. Collected variables included preoperative symptoms, radiographic findings, type and stage of endodontic intervention, and systemic medical conditions. Statistical analysis used chi-square or Fisher exact tests to compare between groups. STROBE and PROBE guidelines were followed. Among 2637 maxillofacial infections of odontogenic origin, 526 cases (19.9%) were related to endodontic treatment. No statistically significant associations were found regarding age, sex, or underlying systemic diseases (p > 0.05). Teeth exhibiting apical radiolucency were at significantly higher risk for abscess development (p < 0.001). Teeth that had undergone definitive root canal filling were significantly less likely to develop abscesses compared to those left without temporary filling after trepanation (p < 0.001) or treated with intracanal medication and temporary filling (p = 0.009). The highest incidence of abscess formation was observed within the first four days post-treatment (p < 0.001). Within the limitations of this retrospective study, abscess formation during or after endodontic treatment was linked to local procedural and radiographic factors, whereas systemic diseases did not demonstrate a measurable influence. The absence of temporary sealing and the presence of apical radiolucency were identified as significant risk indicators and may warrant increased clinical attention, particularly in the early postoperative period. Given the retrospective design and limited sample size, these findings should be interpreted with caution and require confirmation in prospective studies.
Journal of dentistryRoshanak Momen, Joshua Dale, Mithun Suresh, Theodore D Ravenel, Julie Marshall, Chin-Lo Hahn
OBJECTIVES: A robot-assisted haptic guidance system (RA) has recently been introduced to facilitate implant placement. Unlike dynamic navigation systems, this platform uses haptic guidance to constrain operator movement along a predefined path. We hypothesized that RA-guided access preparation would reduce operative time while minimizing the volume of tooth structure removed. Therefore, the aim of this study was to evaluate the effectiveness and precision of the RA approach compared with the freehand (FH) approach across three in vitro endodontic treatment modalities: (A) access to calcified canals, (B) fiber post removal, and (C) endodontic microsurgery. METHODS: Extracted teeth for each treatment modality were divided into three groups: an RA group treated by a resident, an FH group treated by the same resident, and a separate FH group treated by an experienced endodontist. Effectiveness was assessed based on the time required to reach the predefined endpoint for each procedure. Precision was evaluated by measuring the volume of tooth structure removed using cone-beam computed tomography images obtained after treatment. One-way analysis of variance and Kruskal-Wallis tests were used to analyze differences between the RA and FH approaches with respect to operative time, volume of tooth structure removed, and bevel angle. RESULTS: Compared with the FH approach, the RA approach significantly reduced operative time and the volume of tooth structure removed across all three treatment modalities. Additionally, the RA approach resulted in a significantly smaller bevel angle following root-end resection. CONCLUSION: The robot-assisted haptic guidance approach demonstrated improved efficiency and precision in challenging endodontic procedures. CLINICAL SIGNIFICANCE: Robot-assisted haptic guidance may enhance the efficiency and precision of complex endodontic procedures while preserving tooth structure. This technology has potential clinical value in managing challenging conditions requiring procedures such as access to calcified canals, fiber post removal, and endodontic microsurgery.
International dental journalFei Chen, Tianxiao Han, Haili Guo, Gang Wang, Lele Qiu, Jianhui Tang, Jianshe Li, Liping Dong, Yang Huang, Lin Wang, Qiang Luo, Huixia He, Hongbo Li, Peng Xue
OBJECTIVES: To compare the accuracy, instrumentation time, and success rate of three dynamic navigation systems (DNSs)-infrared-active (IA), infrared-passive (IP), and visible light-passive (VP)-with freehand (FH) operation in locating root canals of maxillary and mandibular molars, providing a basis for technique selection in complex endodontic treatments. METHODS: Ninety-six extracted human mandibular molars were randomly assigned to four groups (n = 24/group): IA-DNS, IP-DNS, VP-DNS, and FH (control). Specimens were embedded in plaster and scanned with CBCT (0.3 mm slice thickness). In DNS groups, fiducial markers enabled real-time tracking of the bur position. The FH group used a microscope with CBCT reference. Recorded parameters included: angular deviation (°), three-dimensional deviations at entry and target points (mm), instrumentation time (s), tooth structure loss (mm³), and success rate of canal location. Data were analysed using ANOVA and chi-square tests (α = 0.05). RESULTS: DNS demonstrated significantly higher accuracy than FH. Angular deviations in DNS groups (IA: 0.64° ± 0.34°, IP: 0.59° ± 0.32°, VP: 0.63° ± 0.24°) were 94.3% to 94.7% lower than FH (11.03° ± 4.70°) (P < .001). Three-dimensional deviations at entry (0.57-0.70 mm) and target (0.59-0.80 mm) were significantly smaller than FH (1.64 mm and 1.26 mm, respectively; P < .001). Tooth structure loss in DNS groups (9.79-11.03 mm³) was reduced by 26.8% to 34.6% compared to FH (14.98 mm³; P < .001). No significant difference in operative time was observed among groups (176-183 s, P > .05). Success rate was significantly higher in DNS groups (99.54%, 215/216) than FH (93.06%, 67/72; P = .004). No significant differences were observed among the three DNS types for any parameter. CONCLUSION: DNS significantly enhanced accuracy of root canal location in molars, reducing angular deviation by >94%, minimizing tooth structure loss by >26%, and increasing success rate to 99.5%. Performance was consistent across different optical principles and signal mechanisms, supporting DNS as a viable option for precise management of calcified canals and other nonsurgical endodontic procedures.
International dental journalMohammed Turky, Lakshman Samaranayake, Thanaphum Osathanon, Paul M H Dummer
INTRODUCTION AND AIM: High-quality artificial intelligence (AI) models in endodontics require access to diverse, well-annotated datasets. This review introduces federated learning (FL) as a privacy-preserving framework for collaborative AI in endodontics. METHODS: In this narrative review, a comprehensive literature search was conducted across databases, encompassing studies published up to April 2026. The search strategy was intentionally broad to facilitate a thorough exploration of the evolution of the relevant concepts. However, to ensure consistency in comprehension and analysis, the review was limited to publications in English. Studies describing the fundamentals and applications of FL were reviewed and comparatively analysed. The narrative review served as the framework for outlining implementation pathways, challenges, and research priorities for its application to diagnostic and decision-support tasks. RESULTS: Traditional centralised training methods face legal and ethical challenges due to data protection regulations. FL allows institutions to retain local patient data while contributing model updates to a central server or decentralised network, thus providing a viable alternative. The article explores FL principles, privacy and security mechanisms, architectures, technical challenges, and adversarial risks. Regulatory and ethical considerations hinge on a mix of advanced technical measures and robust organisational practices. A proposed roadmap for implementing FL includes pilot studies, standardised data processes, clinical validation, and regulatory engagement. FL promises to enhance AI development in endodontics while safeguarding patient privacy, with potential benefits in diagnostics and personalised care. CONCLUSION: FL could advance AI integration in endodontics, prioritising the protection of patient privacy. This initiative holds the potential to improve diagnostic processes and facilitate personalised treatment approaches. CLINICAL RELEVANCE: FL enables the development of multicentre AI models without sharing patient data. By leveraging diverse clinical datasets, this approach may improve the accuracy and generalisability of AI systems for endodontic diagnosis, treatment planning, and outcome prediction while preserving patient privacy.
European endodontic journalVerónica-Méndez González, Rodrigo Vargas López, Amaury Pozos-Guillén, Karla Navarrete-Olvera, Mariana Gutiérrez-Sánchez, Dante Arteaga-Martínez, Arturo Garroch…
This study aimed to compare the efficacy of 2 retreatment protocols - SClean® file and R1 ClearSonic™ ultrasonic tip - in removing bioceramic (EndoSequence BC Sealer®, CeraSeal®, Kerr®) and epoxy resin-based (AH Plus®) sealers using micro‑CT analysis. One hundred and four extracted single-rooted teeth were divided into 8 groups according to sealer type and cleaning protocol. Residual sealer volume, surface area, and apical permeability were analysed using Mann-Whitney U and Kruskal-Wallis tests (α=0.05). No technique achieved complete removal, with the highest residue in the apical third. SClean® was more effective on bioceramic sealers (P < .05), while R1 ClearSonic™ showed no significant inter-sealer differences. Apical permeability recovery was greatest with bioceramic sealers, reaching 100% for EndoSequence BC Sealer®. In conclusion, bioceramic sealers are more easily eliminated than epoxy resin-based sealers, though complete removal - particularly apically - remains difficult.
European endodontic journalIbrahim H Abu-Tahun, Hyun Seok Choi, Hyo Chan Cho, Unni Krishnan, Hyeon-Cheol Kim, Sang Won Kwak
OBJECTIVE: This study aimed to investigate the effects of repeated use on the fracture resistance of thermally treated nickel-titanium (NiTi) files with identical S-shaped cross-sections but different kinematics. METHODS: Reciproc Blue (RB; reciprocating, single-file technique) and VDW.Rotate (VR; continuous rotation, multiple-file sequence) were divided into subgroups based on 0, 2, or 4 simulated uses. Each file prepared standardised J-shaped resin canals, with preparation protocols following each manufacturer's recommended clinical sequence. After each usage cycle, files were tested for cyclic fatigue resistance using a custom device simulating each motion at body temperature, and for torsional resistance according to ISO 3630-1. Fractured fragments were examined with a scanning electron microscope. Data were statistically analysed using one way analysis of variance (ANOVA) and Duncan's post hoc tests at a significance level of 95%. RESULTS: Both systems showed increased toughness and distortion angle after 2 uses (P < .05), likely due to stress-induced martensitic (SIM) transformation. RB exhibited higher cyclic fatigue resistance than VR. After 4 uses, mechanical performance declined in both systems (P < .05), while maximum torque remained unchanged (P > .05). Scanning electron microscope (SEM) revealed typical features of cyclic fatigue and torsional fractures, with machining grooves present even in new files. CONCLUSION: Limited repetitive uses of NiTi files can transiently improve torsional and cyclic fatigue resistance. Continuous repetitive use, however, decreases mechanical performance due to fatigue accumulation and microstructural defects. These findings underscore the importance of restricting clinical reuse to preserve the mechanical integrity and safe performance of NiTi rotary instruments.
OBJECTIVE: Pulp capping materials must possess biocompatibility, odontogenic characteristics, and promote mineralisation. The combination of nano α-tricalcium phosphate (nano α-TCP) with silver nanoparticles (AgNPs) yields these features. The objective of this work was to examine the impact of nano-α-TCP and AgNPs on the odontogenic differentiation and mineralisation of human dental pulp stem cells (hDPSCs). METHODS: Composites of nano α-TCP and AgNPs were produced inside a UDMA/TEGDMA resin matrix, with AgNPs varying from 1% to 10% w/w (weight/weight) The morphology and distribution of nano α-TCP and AgNPs were analysed using scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS). The viability of hDPSCs was assessed with the metabolic activity (MTT) test at 24 and 72 hours. The capacity for odontogenesis was evaluated by DSPP (dentin sialophosphoprotein) and dentin matrix protein-1 (DMP-1) proteins on days 3, 7, 14, and 21, while mineralisation was analysed using Alizarin Red on days 14 and 21. A two-way ANOVA was conducted, followed by Tukey's test (P < .05). RESULTS: Scanning electron microscopy -Energy Dispersive X-ray Spectroscopy (SEM-EDS) demonstrated a porous matrix with a uniform distribution of calcium phosphate (CaP) and silver (Ag) content, aligning with the intended composition; certain formulations approximated the Ca/P ratio of hydroxyapatite. The viability assay of hDPSCs indicated that all treatment groups exceeded 80% after 24 and 72 hours. DSPP levels reached their zenith on day 3, diminished from days 7 to 14, and subsequently rose again on day 21, whereas DMP-1 levels exhibited no consistent pattern of increase or decrease until day 21, signifying the advancement of differentiation. The Alizarin Red assay indicated a notable rise in mineral deposits between days 14 and 21. CONCLUSION: Nano α-tricalcium phosphate and AgNPs resin composites demonstrated cytocompatibility, expression of odontogenic markers, and mineralisation-related activity in hDPSCs under in vitro conditions. These findings support the bioactivity of the tested formulations as an experimental proof of concept; however, in vivo and clinical studies are required before any clinical application can be considered.
General dentistryLorena de Mello Alcântara Garrido, Marco Antônio Húngaro Duarte, Milena Perraro Martins, Índia Olinto de Azevedo Queiroz, Ana Grasiela Limoeiro, Clovis Monteir…
This in vitro study aimed to compare the effects of conventional and ultrasonic root canal preparation on the adhesion of glass fiber posts to root canal dentin. A total of 20 human maxillary central incisors were instrumented and then filled with gutta percha and sealant using the lateral condensation technique. The teeth were randomly divided into 2 equal groups (n = 10), gutta percha was removed, and canals were prepared using a different protocol for each group: in the conventional group, a Gates-Glidden drill, a Largo drill, and post bur kit were used; in the ultrasonic group, ultrasonic tips were operated in endo mode. Microcomputed tomography was used to confirm complete removal of the filling material, and fiber posts were cemented with self-adhesive resin cement. The apical ends of the roots were discarded, and the remaining portions were transversely sectioned into 3 segments, each 1.5 mm thick. The sections underwent push-out testing to determine bond strength, and the adhesion defects were examined with scanning electron microscopy and stereomicroscopy to determine the failure mode. Data normality was assessed using the Kolmogorov-Smirnov test, followed by analysis of variance with Tukey test for group comparisons and chi-square tests to evaluate any associations regarding failure mode. A 5% significance level was applied. Tukey tests revealed that the conventional group exhibited statistically significant lower push-out bond strengths than the ultrasonic preparation groups across all thirds; no statistically significant differences were noted among the cervical, middle, and apical thirds within the same group. There were no statistically significant differences in failure modes between the preparation groups, and adhesive failure was the most prevalent mode. The ultrasonic method effectively removed gutta percha from canals and enhanced the bond strength of fiber posts.