Journal of endodontics最新文献

Introduction: Mesenchymal stromal cells (MSCs) have been proposed for tissue regeneration based on their paracrine and immunomodulatory effects. Based on these features, MSCs may regulate inflammation and tissue repair. This case report assessed whether allogeneic bone marrow MSCs (BM-MSCs) can arrest external apical inflammatory resorption (EAIR) in a mature, nonvital traumatized tooth.

Methods: A healthy 14-year-old male with intermittent edema and a sinus tract associated with tooth #9 was referred for endodontic evaluation. Radiographically, tooth #9 showed EAIR with a vertical/diagonal mesial pattern and a 3-mm periapical lesion with widened periodontal ligament space. The root canal was cleaned and shaped; calcium hydroxide was used as interappointment medication, and cryopreserved allogeneic BM-MSCs were thawed, expanded, incorporated into preclotted platelet-rich plasma, and implanted into the pulp cavity. The cervical third was sealed with bioceramic cement and composite.

Results: Cryopreserved BM-MSCs retained fibroblast-like morphology, expressed CD73/CD90/CD105, and showed osteogenic, adipogenic, and chondrogenic differentiation. A BM-MSC/PRP clot was transplanted without complications or adverse events. At 3 months, radiographs showed reduction of the periapical radiolucency with initial bone formation and positive cold and electric pulp test responses. Between 12 and 24 months, reappearance of lamina dura, remodeling of the resorbed surface, and complete radiographic healing with arrest of EAIR were observed. At 48 months, tooth #9 was asymptomatic, responsive to cold and electric pulp test, and showed normal periapical architecture and mineralized tissue within the canal with an apical constriction.

Conclusions: BM-MSC transplantation may arrest EAIR and promote pulp-like and periapical tissue regeneration.

Introduction: This study compared the intracanal microbiome of teeth with apical periodontitis in oncologic and healthy patients using 16S rRNA gene-based next generation sequencing.

Methods: Root canal samples were taken from 46 teeth with pulp necrosis and primary apical periodontitis (23 from oncologic patients and 23 from healthy controls). DNA was extracted and sequenced using the Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene. Bioinformatics processing was conducted using QIIME2 and DADA2. Alpha and beta diversity analyses, genus-level abundance comparisons, and indicator species analyses were performed.

Results: After quality filtering, 3,307,822 sequence reads were retained, averaging 68,912.96 reads/sample, and resulting in 3,241 unique amplicon sequence variants. Oncologic patients exhibited significantly higher bacterial richness (P = .01), while Shannon diversity showed no significant difference between groups. Beta diversity analysis (Bray-Curtis, MDS stress = 0.14) did not reveal significant differences between groups. Indicator species analysis identified some specific taxa more associated with oncologic patients, including the candidate endodontic pathogens Prevotella, Selenomonas, Alloprevotella, Rothia, and Fretibacterium.

Conclusions: The root canal microbiome of oncologic patients with apical periodontitis was broadly similar to that of healthy controls. The oncologic group showed higher species richness, but no significant differences in the overall bacterial diversity or community structure.

Objective: To evaluate the bacterial DNA load reduction in mesial root canals of mandibular molars using quantitative polymerase chain reaction, examining the effects of instrumentation, irrigant type, and their interaction after the use of sonic activation.

Methods: Twenty-one extracted human mandibular molars were sterilized and contaminated with human supragingival plaque under anaerobic conditions for 14 days. After sealing the apices and coating external surfaces to simulate a closed canal system, the teeth were randomly assigned to 3 irrigant groups (n = 7): 7.55% sodium hypochlorite, 1.88% sodium hypochlorite, or sterile saline. Microbiologic sampling was performed at baseline (S1), after preparation to size 25/.04 with sonic activation (S2), and after enlargement to size 30/.04 with sonic activation (S3). Bacterial DNA was quantified by quantitative polymerase chain reaction (Log₁₀ molecules/μL). Data were analyzed using two-way repeated-measures ANOVA with Geisser-Greenhouse correction and Tukey's honest significant difference tests.

Results: The interaction between irrigant type and instrumentation was not significant (P = .852), and irrigant type alone showed no significant effect (P = .502). In contrast, instrumentation significantly reduced bacterial load (P < .0001), accounting for 68.44% of variance. Significant reductions occurred from S1 to both S2 and S3, with no difference between S2 and S3, indicating that most of the decrease in bacterial DNA load occurred during initial enlargement to size 25/.04 with sonic-activated irrigation.

Conclusion: Root canal instrumentation combined with sonic activation was the most significant factor associated with reduction in bacterial DNA load, while irrigant type and concentration provided minimal additional effect.

Introduction: This study evaluated the effect of different sealers on fracture resistance of retreated mandibular premolars and characterized their biomechanical behavior using three-dimensional finite element analysis (FEA).

Methods: One hundred twenty-four single-rooted premolars were instrumented and initially obturated with AH Plus. Twelve teeth with intact fillings served as positive controls, and 12 retreated but unfilled teeth served as negative controls. The remaining samples were retreated and randomly assigned to 5 sealer groups (n = 20): AH Plus, GuttaFlow Bioseal, TotalFill BC, BioRoot RCS, and NeoSealer Flo. After thermocycling, fracture resistance was tested under 45° oblique loading. Corresponding micro-computed tomography-based FEA models were generated to compare von Mises stress distributions with and without a simulated periapical lesion.

Results: Fracture resistance differed significantly among groups (P < .001). The negative control showed the lowest resistance, whereas the positive control exhibited the highest values (P < .05). No statistically significant differences were observed among the experimental sealer groups (P > .05). FEA demonstrated distinct stiffness-dependent patterns: NeoSealer Flo and TotalFill BC concentrated stresses within the sealer, whereas limiting dentinal stress; GuttaFlow Bioseal transmitted greater stresses to dentin; AH Plus and BioRoot RCS showed intermediate responses.

Conclusions: In retreatment conditions, sealer type influences internal stress distribution even when fracture resistance values are comparable. Bioceramic sealers with higher elastic modulus may reduce dentinal stress and enhance biomechanical compatibility. Clinicians should consider not only biological performance but also mechanical compatibility when selecting sealers to support long-term structural preservation of retreated teeth.

Introduction: Regenerating the pulp-dentin complex is challenging due to its distinct biological, anatomical, and mechanical properties. To address this, we explored gelatin-based hydrogels modified by covalently binding vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP2) mimetic peptides to target pulp and dentin regeneration.

Methods: Three distinct hydrogels: GelMA (gelatin methacrylate, 5% w/v), GelNB (norbornene-modified gelatin, 5% w/v), and GelMN (5% GelMA: 5% GelNB = 1:1) were prepared and characterized by scanning electron microscopy (SEM, n = 3), Fourier transform infrared spectroscopy (FTIR, n = 3), and swelling ratio analysis (n = 3). Human dental pulp stem cells (DPSCs) were encapsulated to assess viability (live/dead staining, n = 3) and spreading (n = 3). DPSCs and human umbilical vein endothelial cells were cocultured in a VEGF mimetic peptide (200 μg/ml) functionalized GelMN hydrogel to evaluate vascular structure formation (n = 3). Conversely, DPSCs were encapsulated in a BMP2 mimetic peptide (20 μM) functionalized GelMA hydrogel to investigate the odontogenic differentiation (n = 3).

Results: SEM analysis showed GelMA exhibited a denser, more tightly crosslinked network and smaller pore size compared to GelNB/GelMN. FTIR confirmed the chemical composition of all 3 hydrogels, and the swelling ratio demonstrated no significant difference among them. All hydrogels exhibited excellent biocompatibility and supported cell viability after culturing with DPSCs. VEGF mimetic peptide in GelMN enhanced vascular tube formation by human umbilical vein endothelial cells supported by DPSCs. In parallel, BMP2 mimetic peptide in GelMA significantly boosted the odonto-/osteogenic differentiation of DPSCs, as indicated by the expression of dentin sialophosphoprotein, alkaline phosphatase, and mineralization levels.

Conclusion: VEGF and BMP2 mimetic peptide-functionalized gelatin hydrogels is a promising approach to enhance pulp-dentin complex regeneration.

Introduction: Generative large language models (LLMs) are increasingly used in dentistry, yet their guideline-based diagnostic accuracy and reproducibility remain uncertain. Position statements from the American Association of Endodontists and the European Society of Endodontology provide rigorous, evidence-based standards, making them an ideal benchmark to assess alignment of LLM outputs with endodontic best practices.

Methods: This study was conducted according to Transparent Reporting of a Multivariable Model for Individual Prognosis or Diagnosis-Large Language Models guidelines, evaluated 11 LLMs: ChatGPT 5, ChatGPT 4o, ChatGPT o3, Gemini 2.5 Flash, Gemini 2.5 Pro, Claude Sonnet 4, Claude Opus 4, Perplexity R1 1776, Perplexity Sonar, DeepSeek, and DeepSeek DeepThink R1. Sixty multiple-choice questions derived from American Association of Endodontists and European Society of Endodontology position statements were administered to each model in 5 rounds, generating 3300 responses. The primary outcome was all-correct accuracy and the secondary outcome was intra-model consistency. Comparisons were performed with chi-square tests and Bonferroni adjustment.

Results: All-correct accuracy varied significantly (χ² = 50.56, df = 10, P < .001). ChatGPT 4o and Claude Opus 4 achieved 95.0% accuracy, followed by ChatGPT 5, Claude Sonnet 4, Gemini 2.5 Flash, and Gemini 2.5 Pro (93.3%), and ChatGPT o3 (90.0%). DeepSeek DeepThink R1 scored 86.7%, Perplexity R1 1776 83.3%, Perplexity Sonar 81.7%, and DeepSeek 63.3%. Consistency exceeded 90% for most models, peaking at 98.3% for top performers but falling to 75.0% for DeepSeek.

Conclusions: Most LLMs demonstrated high accuracy and reproducibility when benchmarked against authoritative endodontic guidelines. Despite notable progress over earlier generations, performance variability and confidently incorrect outputs highlight the need for rigorous validation and expert oversight before clinical integration.