Journal of endodontics最新文献

The dental pulp is a highly vascularized and innervated connective tissue located at the central part of the tooth and composed of a diverse array of cell types, including fibroblasts, multipotent mesenchymal stem cell, odontoblasts, and immune cells. Traumatic injuries and carious lesions can lead to dental pulp pathologies that often require replacement of damaged tissue with inert materials. Despite significant progress in recent years, cell-based dental pulp regenerative therapies remain distant from clinical applications. The lack of platforms capable of accurately modeling the human dental pulp in all its complexity hampers the development of novel therapeutic strategies. In response, numerous efforts have been focused on the development of innovative microfluidic systems designed to emulate human dental pulp physiology. These "dental pulp-on-chip" platforms enable the recreation of structural and functional complexity in an in vivo-like environment, opening new horizons for patient-specific endodontic therapies and providing valuable tools for targeted drug testing. This review focuses on state-of-the-art microfluidic devices designed to emulate the dental pulp and their specific applications in dental materials testing, drug evaluation, and pulp regeneration. By integrating multiple cell types, biomaterials, and bioactive cues within dynamic microenvironments, "dental pulp-on-chip" devices overcome the constraints of traditional in vitro cultures and animal models and enable the assessment of treatment-induced systemic effects, an aspect often overlooked in dental research. Continued advancements in "dental pulp-on-chip" technology will be pivotal for bridging preclinical research and clinical practice in dental medicine.

Introduction: Endodontic kinematics are associated with varying levels of inflammatory response and postoperative pain. The effect of apical motion algorithms in integrated endodontic motors on this relationship has not been clinically evaluated. This study aimed to evaluate the effects of root canal preparation with continuous rotation (CR) and 2 different apical action algorithms on periapical inflammation mediator and patient-reported pain outcomes.

Methods: Sixty-six patients with asymptomatic pulpitis, symptomatic irreversible pulpitis, and normal pulps to be exposed for prosthetic preparation requiring endodontic treatment were randomly assigned to three groups: CR, auto apical reverse (AAR) and auto apical slow-down. Root canal instrumentation was performed and apical exudate samples were collected on postoperative Days 0 and 3 are analyzed for inflammatory mediators, including substance P (SP), tumor necrosis factor-α, interleukin-1β and interleukin-6. Preoperative and postoperative Day 3 visual analog scale pain scores were recorded.

Results: SP levels on Day 0 (P < .001) and Day 3 (P = .001) were significantly higher in the AAR group. No significant differences were found between the groups regarding postoperative pain scores. When cytokines were assessed in terms of percent change, only tumor necrosis factor-α showed a significant increase in the auto apical slow-down group compared to the CR group (P = .035).

Conclusion: This study demonstrated that different apical actions influence the levels of inflammatory mediators in periapical tissues. AAR was found to be associated with higher SP release on both sampling times. However, the variations in mediator levels didn't translate into differences in pain outcomes. Further research is needed to clarify the effects of apical actions on inflammation, pain, and overall clinical outcomes.

Introduction: To investigate the geometric angle method of "danger zone" (DZ) position in the mesial roots of mandibular first molars (MFMs) using cone-beam computed tomography (CBCT) and micro-computed tomography (Micro-CT).

Methods: The CBCT images of 949 MFMs with mesial roots of single root and 2 root canals were collected and analyzed with DZ and α_D (the angle between the line extending from the center of buccal/lingual root canal to DZ and the line connecting the centers of the buccal and lingual root canals) of the mesial roots in the coronal and middle thirds of roots. Thirty-four MFMs with similar root canal morphologies were analyzed using Micro-CT to validate the geometric positioning method based on CBCT. The association of α_D with the root lengths, inter-orifice canal distance (D_R-R), age and gender were subsequently investigated. Values with P < .05 were considered statistically significant.

Results: The DZ of MFMs was mainly located in the middle thirds of the distal wall, with an average thickness of 0.818 ± 0.143 mm. The average α_D was 71.9 ± 9.0°, ranging from 42.7° to 99.9° and showed approximately 87.8% of value concentrated within the range of 60.1°-86.2°. The α_D was negatively correlated with the D_R-R (P < .01) and had no correlation with age or gender (P > .05). Results of the Micro-CT analyses showed that the α_D was 70.4 ± 7.3°, ranging from 48.9° to 85.6°, and 92.7% of the α_D were also within the range of 60.1°-86.2° established by CBCT.

Conclusions: From a geometric perspective, the distribution of DZ in the mesial roots of MFMs demonstrated a relatively consistent spatial pattern. This predictable localization may assist clinicians in accurately identifying DZ positions and improving treatment planning.

Introduction: This study compared the quality of placement and removal of a bioceramic intracanal medication (Bio-C Temp) and a calcium hydroxide-based medication (UltraCal XS) using micro-computed tomography (micro-CT) analysis.

Methods: Mandibular molars with Vertucci type II mesial root configuration were selected based on micro-CT evaluation. Teeth were allocated into 2 matched groups according to root canal anatomy and volume as similar as possible. Canals were instrumented using WaveOne Gold Primary files. Medications were injected into the canal using a syringe according to the manufacturer's instructions: UltraCal XS (Ultradent, USA) or Bio-C Temp (Angelus, Brazil). After 15 days, the medication was removed by using ultrasonic activation of 2.5% NaOCl. Micro-CT scans were taken after instrumentation, and medication placement and removal to quantify the canal volume and medication volume.

Results: No significant differences in medication filling or removal were observed between groups at either the 4-mm or 8-mm canal levels from the apical foramen (P > .05). After placement, Bio-C Temp filled 73% of the full canal length and 30% of the apical 4-mm segment, while UltraCal XS filled 57% and 25%, respectively. The removal protocol substantially reduced medication volumes in both groups, with mean reductions of 91.9% and 88.5% for Bio-C Temp and 82.6% and 81.3% for UltraCal XS in the full canal and apical segments, respectively. Complete elimination was observed in only a few specimens from both groups.

Conclusion: UltraCal XS and Bio-C Temp exhibited similar results in terms of placement and removal. Neither material completely filled the prepared canal, and removal with ultrasonic activation also failed to achieve complete elimination in most specimens.

Introduction: Dental pulp stem cells have been explored as a potential source for dentin-pulp complex regeneration because of their pluripotency and differentiation capacity. However, cell-based approaches require enzymatic digestion and in vitro expansion, which may alter cell properties and hinder clinical translation. This preliminary proof-of-principle study examines a tissue-based alternative using freshly minced pulp (MP) in an ectopic mouse model as a potentially translatable approach for regenerative endodontics.

Methods: Human dental pulp tissue was either minced or enzymatically digested, seeded onto collagen type I scaffolds, inserted into root fragments, and implanted subcutaneously into immunocompromised mice.

Results: Histology revealed that MP grafting generated well-organized dentin-pulp-like tissue with high cellularity, vascularization, mineralization, and odontoblast-like cells extending processes into dentinal tubules, whereas dental pulp stem cell grafts formed less organized tissue and mineral deposits. MP-derived tissues also exhibited angiogenic potential, forming vessel-like structures containing pericytes and endothelial cells.

Conclusions: This preliminary in vivo mouse study suggests the feasibility of MP transplantation and its potential for dentin-pulp complex regeneration, though further studies are needed to assess long-term outcomes and clinical applicability.

Introduction: Medication-related osteonecrosis of the jaws (MRONJ) is a condition that causes progressive bone destruction and compromises patients' function, aesthetics, and quality of life.

Objectives: This study aims to investigate the role of untreated apical periodontitis (AP) in the development of MRONJ.

Methods: A comprehensive search was performed in PubMed/MEDLINE, Web of Science, Scopus, and Embase. Gray literature was assessed using the ProQuest database. The eligibility criteria consisted of (1) preclinical studies; (2) use of antiresorptive, antiangiogenics, or other drugs known to cause MRONJ; (3) studies evaluating the development of osteonecrosis in regions of AP lesions. The following studies were excluded: (1) non-animal studies. Two independent reviewers performed data extraction and the assessment of the risk of bias.

Results: From an initial dataset of 239 records, we included 11 studies. Induction of periapical lesions was performed most often after the administration of bisphosphonates. Zoledronic acid was the most used drug. Histologic or clinical evidence of MRONJ in areas of untreated AP was reported in 72.72% of the studies. Furthermore, areas with AP presented MRONJ more frequently, with or without clinical signs.

Conclusions: This systematic review of preclinical studies indicates that untreated AP, in the context of antiresorptive therapy, may increase the risk of MRONJ. Our findings provide mechanistic insights that clarify how AP may contribute to MRONJ pathogenesis, offering a theoretical background to support clinical observations. While human studies suggest a potential pathogenic interaction, they remain limited by heterogeneous designs, variable definitions of oral infections, and frequent grouping of AP with other conditions. These limitations underscore the translational significance of our preclinical analysis. Overall, our results reinforce the importance of early diagnosis and management of endodontic infections in patients receiving antiresorptive particularly cancer patients exposed to higher cumulative doses and highlight the need for well-designed prospective clinical studies to determine whether AP constitutes an independent risk factor for MRONJ.