Introduction: Preserving the health and structure of primary teeth is crucial for a child’s growth and development. Premature extraction of primary teeth can lead to unfavourable changes in the eruption pattern and alignment of permanent teeth. To ensure the success of endodontic therapy in primary teeth, it is essential to use a biocompatible obturating material with effective antimicrobial properties. An ideal root canal filling material for primary teeth should not harm the periapical tissues, should promote the normal development of the permanent successor tooth and should undergo resorption simultaneously with root resorption. Additionally, it should be easy to place, adhere to the root canal walls, resorb if extruded beyond the apex, appear radiopaque on radiographs and not cause tooth discolouration. Zinc oxide Eugenol (ZnOE), iodoform-based pastes and calcium hydroxide are commonly used obturating materials for primary teeth. However, ZnOE has several disadvantages, including slow resorption, potential tissue irritation, bone and cementum necrosis and interference with the eruption of permanent teeth. Theobromine is a crystalline, water-insoluble alkaloid found in cacao plants. It has been shown to strengthen tooth enamel and exhibit antibacterial activity against microorganisms such as Lactobacillus acidophilus and Enterococcus faecalis. Need of the study: There is a need to identify root canal filling materials suitable for primary teeth that combine effective antimicrobial activity with biocompatibility and appropriate resorbability. Existing materials, such as zinc oxide eugenol, possess limitations that may compromise treatment outcomes. Therefore, investigating formulations enhanced with theobromine may represent a potential advancement in paediatric endodontics. Aim: To assess and compare the antimicrobial effectiveness of root canal filling materials, including zinc oxide eugenol and calcium hydroxide, combined with theobromine in primary teeth. Materials and Methods: An in-vitro study will be conducted at the Department of Paediatric and Preventive Dentistry at Sharad Pawar Dental College and Hospital, in collaboration with the Department of Microbiology, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research (DMIHER), Sawangi, Wardha, Maharashtra, India, involving 25 patients aged 4-8 years. Microbial samples will be collected from infected primary molar teeth. The antimicrobial efficacy of four different root canal filling materials—zinc oxide mixed with theobromine, zinc oxide eugenol, calcium hydroxide mixed with theobromine and calcium hydroxide mixed with saline—will be evaluated. Vaseline will serve as the negative control. The mean zone of inhibition will be considered the primary outcome measure. Data will be tested for normality using the Shapiro– Wilk test. If the data are normally distributed, one-way Analysis of Variance (ANOVA) followed by Tukey’s post hoc test will be applied. If the data are not normally distributed, the Kruskal– Wallis test followed by the Mann-Whitney U test with Bonferroni correction will be used. A p-value of <0.05 will be considered statistically significant.

Does adjunctive photodynamic therapy enhance sodium hypochlorite-based root canal disinfection? A systematic review and meta-analysis.

SHED-Derived Exosomes Attenuate Osteoclastogenesis to Ameliorate Apical Periodontitis in Rats.

Interactive study blocks for hydraulic cement research in endodontics.

Antimicrobial resistance and biofilm-associated infections present major challenges in oral healthcare, necessitating sustainable nanomaterials with multifunctional efficacy. This study reports the green synthesis of zinc oxide nanoparticles (ZnO NPs) from Pergularia daemia (P. daemia) fibre (PDF) extracts and evaluates their structural, thermal, and biological properties for dental and biomedical applications. ZnO NPs were synthesised using aqueous PDF extracts as natural reducing and stabilising agents. Structural crystallinity was examined by X-ray diffraction (XRD), functional groups by Fourier-transform infrared spectroscopy (FTIR), morphology by scanning electron microscopy (SEM), and thermal stability by thermogravimetric analysis (TGA). Antibacterial performance against Klebsiella pneumoniae and Streptococcus mutans was assessed via agar well diffusion, while antibiofilm efficacy was evaluated using confocal laser scanning microscopy (CLSM). XRD confirmed a semi-crystalline ZnO phase with a crystallite size of 28.6 nm and a crystallinity index of 21%. FTIR revealed hydroxyl, carbonyl, and carboxylate groups contributing to nanoparticle stabilisation. SEM micrographs showed irregular, porous, and agglomerated morphologies spanning nanometre to submicron scales. TGA indicated multi-step degradation with a stable residual fraction of ∼14% at 670 °C. Antibacterial assays demonstrated strong inhibition zones (27 mm, 32 mm at 75 µg; 31 mm, 41 mm at 100 µg), comparable to streptomycin (34 mm and 43 mm). CLSM confirmed significant antibiofilm activity through membrane disruption and reduced bacterial viability. The enhanced antibacterial and antibiofilm performance of PDF-derived ZnO NPs arises from synergistic effects of nanoparticle cores, reactive oxygen species generation, and phytochemical surface functionalization. Their stability and bioactivity underscore their promise as sustainable nanomaterials. PDF-mediated ZnO NPs show potential for dental applications, including caries prevention, root canal disinfection, and biofilm-resistant coatings for restorative and implant materials. Their multifunctional profile further supports broader biomedical use in antimicrobial therapy, drug delivery, and composite engineering.

This systematic review evaluated the antibacterial efficacy of the GentleWave system compared with other endodontic irrigation systems. A comprehensive literature search was conducted across multiple databases (PubMed, MEDLINE, Web of Science, Scopus). The eligibility criteria were formulated using the PICOS framework, focusing on the antibacterial efficacy of the GentleWave system compared to other irrigation methods. A total of 2327 articles were screened, with five meeting the selection criteria for inclusion. Four studies were conducted in vitro, one in ex vivo, and various tooth types were tested. A bias assessment was conducted using the QUIN tool. Four studies had a low risk of bias, with one study scoring medium risk. All concluded that the GentleWave system significantly reduced microbial counts. Emerging evidence suggests that GentleWave may provide superior antibacterial efficacy in root canal therapy, making it a compelling option. However, further research is needed to confirm its benefits and promote broader adoption.

Artificial intelligence-based human dental root canal segmentation performed using CBCT images

Mandibular incisors are traditionally described as having a single root and a single canal. Traditionally, it is considered the simplest tooth to treat endodontically. However, numerous studies have reported anatomical variations in the anterior teeth of the mandible. Mandibular incisors frequently exhibit anatomical variations, including the presence of a second root canal, which is often located lingually. This lingually placed canal is often overlooked by clinicians due to the narrow mesiodistal dimension of the tooth, superimposition on conventional radiographs, and limited understanding of the complex internal anatomy. The clinicians often fail to locate the lingual canal due to a lack of experience and understanding of root canal morphology, leading to continuing periapical pathology and eventual endodontic failure. Consequently, a thorough diagnostic approach is essential. The use of multiple angulated periapical radiographs, and where indicated, advanced imaging techniques, can greatly enhance the detection of canal bifurcations. In addition, carefully modified access cavity designs that extend slightly towards the cingulum improve the likelihood of locating the lingual canal orifice. The report emphasizes careful radiographic evaluation, modified access cavity design, and the use of magnification for identification and management of the lingual canal. This case series aims to describe the diagnosis and location of nonsurgical endodontic management of mandibular incisors with two canals, emphasizing the clinical and radiographic identification for successful treatment. Keywords: Endodontic treatment, Two canals, Bifurcation

This cross-sectional study aimed to compare the endodontic microbiome assessed from root canals of teeth associated with either symptomatic or asymptomatic apical periodontitis and analysed by 16S rDNA gene sequencing. 60 teeth presenting clinical and radiographic signs of symptomatic or asymptomatic apical periodontitis (n = 30) were included in this cross-sectional study after participants had given their written informed consent. After isolation with rubber dam, disinfection and access cavity preparation, glide paths were prepared using C-Pilot Files and K-Files under electronic root canal length control. Microbial samples were collected from a total of 120 root canals (symptomatic apical periodontitis, SAP: n = 62, asymptomatic apical periodontitis, AAP: n = 58) each with a sterile file (size 20/0.06) in a single length technique. Only one specimen per tooth was included in the analysis; in multi-rooted teeth, the specimen with highest sequencing depth. After DNA extraction, the hypervariable region V4 of the bacterial 16 S rRNA gene was amplified and sequenced (Illumina MiSeq). Taxonomy was assigned based on the expanded Human Oral Microbiome Database (eHOMD). Statistical analysis of diversity parameters comprised Mann-Whitney U tests and PERMANOVA. Compositional differences were evaluated by differential abundance analyses using DESeq2, LinDA, and ANCOM-BC2 methods. No differences were observed in richness and diversity (Shannon diversity index) on the genus or ASV level (p > 0.05). According to PERMANOVA, SAP and AAP microbiomes did not differ significantly both on genus and ASV levels (p > 0.05). Among highly abundant genera, Fusobacterium was indicated to be more abundant in SAP samples whereas Actinomyces was more abundant in AAP samples. The expression of clinical symptoms in apical periodontitis does not appear to be determined by specific microorganisms but may instead reflect shifts of the relative abundance of the microbial community.

Self-propelled Janus platinum mesoporous-silica nanoparticles for enhanced endodontic treatment.

Protoporphyrin IX fluorescence for real-time visualization of bacterial persistence during root canal treatment.

A micro-CT-integrated three-dimensional simulation framework (3D-SALAM) was developed to address the long-standing limitations of destructive, poorly reproducible leakage tests traditionally used to evaluate the sealing performance of root canal biomaterials. Despite decades of research, the long-term stability of root canal fillings remains uncertain because existing in vitro models fail to capture the complex, three-dimensional transport of fluids through micro-void networks. To bridge this methodological gap, the present study introduces and demonstrates 3D-SALAM-an innovative, non-destructive platform that integrates high-resolution micro-computed tomography with computational fluid dynamics to mechanistically characterise void geometry, connectivity, and fluid transport behaviour within obturated teeth. Micro-CT datasets (10μm voxel size) from human single-rooted teeth were converted into numerical meshes for finite-volume simulations, systematically varying surface wettability (contact angle 25°-150°), injection velocity, and applied pressure. These simulations are presented as a proof-of-concept application of the workflow, illustrating how hydrophilic surfaces achieved up to 92% void saturation with less than 10% trapped air, while hydrophobic domains retained over 25%. Medium injection velocities produced optimal filling efficiency by balancing capillary and viscous forces, and applied pressure accelerated transport but induced pronounced local concentration gradients. This proof-of-concept study demonstrates that 3D-SALAM enables reproducible, quantitative, and mechanistic mapping of fluid dynamics in complex biomaterial architectures. Beyond characterising initial obturation quality, this approach provides a methodological foundation for longitudinal evaluation of material degradation, interfacial stability, and fluid-mediated transport phenomena. The framework's adaptability also extends its relevance to a wide range of porous and composite biomaterials in regenerative medicine and biomedical engineering, where void connectivity and capillary behaviour critically influence long-term performance.

Root canal segmentation from cone-beam computed tomography guided by micro-computed tomography based on deep learning.

Radiographic evaluation of preoperative and postoperative quality of root canal retreatments: a retrospective study.

To compare the accuracy of the Raypex-6 apex locator and Cone-beam computed tomography (CBCT) in measuring root canal length under different apical foramen diameters and root canal curvature angles. Sixty in vitro root canal specimens were selected. The apical foramen was destroyed retrogradely, and the apical foramen diameter was adjusted artificially to range from 0.2mm to 2.0mm. A stereomicroscope was used to determine the actual root canal length. CBCT and the Raypex-6 apex locator were used to independently measure root canal length. We compared the actual length with that measured by CBCT and the Raypex-6 apex locator. A chi-square test was applied to the data, with measurement differences of 0-0.5mm classified as accurate. Finally, differential analysis and correlation analysis were performed. CBCT accuracy did not differ significantly across apical foramen diameter or root canal curvature angle groups (P > 0.05). Raypex-6 apex locator accuracy also showed no significant differences among groups stratified by root canal curvature angle (P > 0.05). In contrast, Raypex-6 apex locator accuracy varied significantly with apical foramen diameter and area (P < 0.001). The accuracy of CBCT and Raypex-6 apex locator for measuring root canal length does not depend on the root canal curvature angle. However, when the apical foramen diameter exceeds 1.6mm, or the apical foramen area exceeds 1.844mm², Raypex-6 apex locator accuracy decreases significantly. Therefore, CBCT is recommended for clinical root canal length measurement under these conditions.

Background and objectives: Head and neck cancer patients frequently undergo radiotherapy, which can affect the properties of dental hard tissues. This study aimed to evaluate the effects of root canal treatment, radiotherapy, and sonic activation during irrigation on the fracture resistance of mandibular anterior teeth. Methods: 80 extracted mandibular anterior teeth were randomly divided into five groups: untreated control (Group I); root canal treatment without radiotherapy or sonic activation (Group II); root canal treatment without radiotherapy but with sonic activation (Group III); root canal treatment with 70 Gray (Gy) radiotherapy and sonic activation (Group IV); and root canal treatment with radiotherapy but without sonic activation (Group V). Radiotherapy was administered in fractionated doses (2 Gy/day, 5 days/week) over 7 weeks. Following instrumentation, root canal obturation was performed accordingly. Fracture resistance was measured using a universal testing apparatus with vertical loading until fracture. Statistical analyses included Shapiro-Wilk normality testing followed by appropriate non-parametric Kruskal-Wallis test followed by Dunn's post hoc test with Bonferroni correction for multiple comparisons. Results: All root canal-treated groups exhibited significantly lower fracture resistance compared to the untreated control group [1572.3 (1217.0-1841.2) N, p < 0.05]. No statistically significant differences were observed between irradiated and non-irradiated groups (p > 0.05). Similarly, sonic activation during irrigation did not significantly affect the fracture resistance values (p > 0.05). Conclusions: Under the specific conditions of this in vitro protocol, fractionated radiotherapy and sonic activation did not demonstrate statistically significant effects on fracture resistance in mandibular anterior teeth, while endodontic procedures reduced fracture resistance.

Özen MM, Karataş E. Effect of Cavity Design on Bacterial Reduction in Root Canals and Postoperative Pain Level: A Randomised Controlled Trial. Aust Endod J. 2025. https://doi.org/10.1111/aej.12976 . A randomised controlled trial evaluated the impact of endodontic access cavity design on intra-canal bacterial reduction and postoperative pain. Patients were allocated to either the Traditional Conservative Endodontic Cavity (TEC) or Truss Endodontic Cavity (TREC) group using computer randomisation. Microbial samples were collected from the mesial root canals of lower molars at baseline and following chemo-mechanical preparation. The total number of bacteria present and the percentage reduction following instrumentation were analysed via real-time quantitative polymerase chain reaction (RT-qPCR). Samples were evaluated for bacterial load using 16S rRNA universal primers. Postoperative pain was recorded daily for 7-days using a Visual Analogue Scale (VAS). 250 patients attended for assessment at the Endodontics Clinic of A.U. Faculty of Dentistry, Turkey. 100 patients (n = 50 per group) met the inclusion criteria (mainly including necrotic mandibular molars with asymptomatic apical periodontitis, where there has been complete root development), 96 patients completed the study (n = 48 per group). Sample size calculation to achieve 95% power and 5% alpha error identified a minimum of 17 participants were required to evaluate antibacterial efficacy, with 27 participants required to evaluate postoperative pain. The statistical power was enhanced by sampling 50 patients in each of the observed groups. Blinding of operators was not possible, and information about individuals conducting the analysis was not included. Statistical analysis was performed using SPSS v20.0. Categorical variables were analysed using the Chi-square test. Normality and homogeneity of numerical data were evaluated using the Kolmogorov-Smirnov and Levene's tests, respectively. Given the non-normal distribution of the data, intergroup comparisons of age, bacterial load, and post-operative pain levels were conducted using the Mann-Whiteny U test. To compare bacterial load and postoperative pain levels within the groups, the Wilcoxon test and Friedman test were applied, respectively. Statistical evaluations were carried out at the 95% confidence interval. Intra-canal bacterial count was significantly reduced in both groups following chemo-mechanical preparation. There was a bacterial load reduction from 6.4 × 105 to 4.8 × 104 (96.32%) in the TEC group and a reduction from 6.7 × 105 to 5.2 × 104 (92.32%) in the TREC group. This difference in the percentage of total bacterial count reduction was statistically significant between the groups (p > 0.05). Therefore, the null hypothesis can be rejected at the 95% confidence interval. For postoperative pain, both groups demonstrated a statistically significant reduction in postoperative pain levels from day 1 to day 7. There was no statistically significant difference in pain levels between the two groups at any time point. Endodontic access cavity design impacts reduction in bacterial load following chemo-mechanical preparation. The TEC allowed for greater reduction in bacterial levels compared to the TREC. This is likely due to reduced access restricting effective debridement. There are benefits to retaining more dentine with regards to improved fracture resistance following treatment, so further research is required in this area. Additionally, neither the TEC nor TREC had any impact on postoperative pain levels.

The present case report aimed to present an immunohistological analysis of newly formed intracanal tissues in a traumatised immature permanent incisor with pulp necrosis and apical periodontitis following RET. A 7-year-old girl sustained a combined traumatic dental injury, an uncomplicated crown fracture and lateral luxation, affecting an immature maxillary central incisor. The tooth subsequently developed pulpal necrosis and apical periodontitis and was treated with RET using calcium hydroxide as an intracanal medicament. A blood clot served as the scaffold, followed by placement of calcium silicate cement (Biodentine®) and a definitive resin composite restoration. During follow-up, the tooth developed ankylosis with progressive infraocclusion. At 13years of age, the tooth was extracted, and prosthetic rehabilitation was completed using a resin-bonded Rochette bridge. Histological and immunohistological analyses revealed a heterogeneous mixture of mineralised and connective tissues within the root canal space. The tissues demonstrated infiltration of fibroblast-like cells, resorptive cells, blood vessels and nerve fibres. Numerous fibrous cystic structures containing cholesterol crystals were identified in the middle third of the root canal. The newly formed intracanal tissues demonstrated limited similarity to intact odontogenic tissues. Both inflammatory root resorption and ankylosis-related replacement resorption, likely associated with the initial luxation injury, were observed. The presence of cholesterol crystal deposits represents a novel finding that may provide new insights into the biological processes occurring after RET. As cellular events following RET cannot be fully controlled clinically, the risk of unfavourable outcomes should be considered carefully, particularly in cases involving luxation injuries.

To describe the knowledge of dentists and laypeople regarding the longevity and success rate of various restorative treatments in dentistry. This observational cross-sectional study was conducted in two phases. In phase 1, a guided interview assessing the longevity of various restorative treatments (including direct composite resin, ceramic veneers, indirect restorations, success of root canal treatments, and implant-supported prosthesis) was administered to 20 dental surgeons. Based on the analysis of the responses from phase 1, an objective questionnaire was developed and applied online to a convenience sample of dentists and laypeople. A descriptive analysis of the responses was performed, and the data were compared with the existing literature. Additionally, the association between the characteristics of the dentists and their responses was examined. Phase 1 revealed considerable disparity in the longevity values reported by professionals for the same treatments. This heterogeneity of responses was instrumental in formulating the answer choices for the objective questionnaire used in the next phase. In Phase 2, 212 dentists and 398 laypeople responded to the survey. Of the laypeople, 68.6% visited the dentist in the past year, and 11.1% based their responses on dentist guidance. At least 11.3% of professionals couldn't identify the best option for describing treatment success or longevity, and responses varied greatly. The percentage of responses aligned with reference literature were: 43.4% for the longevity of composite resin restorations, 60.8% for ceramic veneers, 62.3% for indirect restorations in posterior teeth, 67.9% for successful root canal treatments, and 53.3% for implant-supported prostheses. There is variability in the responses, with a significant portion of dentists demonstrating difficulty in providing accurate answers on the topic, while a considerable proportion of laypeople expect dental procedures to last a lifetime.

This study aimed to evaluate the effects of heat setting, plugger size, and dentin thickness on the temperature increase at the root surface during warm vertical compaction. A total of 96 mandibular premolars, 36 maxillary, and 36 mandibular central incisors were selected. All root canals were prepared using a 30/07 file. AH Plus sealer and gutta-percha were placed into the canals. In the mandibular premolars, small (40/0.025), medium (50/0.05), and large (60/0.06) pluggers were used, each set at temperatures of 180, 200, 220, and 250°C. For the maxillary and mandibular incisors, a medium-sized plugger was used across all heat settings. Heat was applied to each sample for 3s, and the maximum temperature was recorded during warm vertical compaction of gutta-percha using an infrared thermal camera. Multiple-linear regression models with dummy variables were utilized to estimate the predictive influence of heat settings, plugger sizes, and dentine thickness on root surface temperature. At 200 and 220°C, the large plugger was associated with a significantly greater temperature increase compared to the small plugger. However, no significant interaction was observed between 250°C setting and pluggers. Interaction between dentin thickness and heat setting indicated that thin dentin was associated with greater temperature increases at 220 and 250°C.