ABSTRACT Periapical cysts present with an epithelium deriving from the epithelial rests of Malassez, which express growth factors. The aim was to evaluate the expression of nerve growth factor (NGF) and its receptors, TrkA and p75NTR in periapical cysts. Immunohistochemistry was carried out in 47 paraffin‐embedded periapical cysts. Staining score was based on intensity and extent of immunoexpression. NGF was predominantly expressed in the cystic epithelium, nerve fibres, lymphocytes and endothelial cells; TrkA was mainly localized to the epithelial basement membrane zone and further expressed in nerve fibres, whereas p75NTR expression was limited and mutually opposed to that of TrkA. These findings suggest a potential role for NGF‐mediated signalling pathways in the pathogenesis and biological behaviour of periapical cysts. Further studies are required to validate these observations and to provide additional insights into the role of NGF, TrkA, and p75NTR in the development, maintenance, and possible healing of periapical cysts.
ABSTRACT Understanding the interfacial layer (IFL) between hydraulic calcium silicate cements (CSCs) and root dentine is essential for optimising CSC performance and developing next‐generation biomaterials. This scholarly review summarises current evidence on IFL composition, formation, structure, and clinical significance. An electronic search of PubMed, Web of Science, and Scopus identified relevant studies using 15 keywords, including ‘interfacial layer.’ A total of 115 articles were classified into three areas: CSC hydration, IFL formation and structure, and clinical implications. Evidence indicates that the IFL forms through hydration‐driven reactions and intratubular mineralisation, creating mechanical interlocking and chemical bonding that improve interfacial integrity and sealing ability. These interactions may reinforce dentine, reduce microleakage, and maintain antibacterial activity against intracanal microorganisms, thereby enhancing endodontic outcomes. Further well‐designed studies are needed to clarify the IFL's long‐term behaviour under clinical conditions and optimise interfacial stability while preserving dentine integrity.
This retrospective multicentre cross-sectional study aimed to determine the prevalence and characteristics of C-shaped canals in Chilean mandibular molars using cone-beam computed tomography (CBCT) and to assess associations with demographic and geographic variables. A total of 5660 mandibular molars from CBCT scans obtained from imaging centres across different regions of Chile were analysed. External root morphology was categorized according to root fusion, and C-shaped canals were classified using Fan's classification at five axial levels. The prevalence of C-shaped canals was 9.88%, with most cases occurring in mandibular second molars (93.92%) and bilateral occurrence observed in 53.87% of affected individuals. Their distribution differed significantly across geographic regions (p = 0.002). Regression analysis accounting for within-patient clustering showed that female sex was significantly associated with their presence (OR = 1.74), whereas age showed no significant association. All C-shaped canals showed root fusion. These findings provide population-specific data for improving diagnostic accuracy and endodontic treatment planning.
Oxidative stress in inflamed pulp tissue compromises dental pulp stem cell survival, yet whether bioceramic materials preserve mitochondrial homeostasis under such conditions remains unclear. The present study demonstrates that iRoot BP Plus, a premixed calcium silicate cement, protects human dental pulp stem cells (hDPSCs) from H2O2-induced oxidative injury through comprehensive mitochondrial protection. iRoot BP Plus significantly restored cell viability, reduced intracellular ROS accumulation, and stabilized mitochondrial membrane potential. Morphometric analysis revealed preserved mitochondrial network integrity with maintained aspect ratio and branching complexity. Mechanistically, iRoot BP Plus upregulated biogenesis regulators (PGC-1 alpha, TFAM, NRF-1), suppressed fission gene DRP1 overexpression, and restored fusion gene MFN2 expression. These findings establish that iRoot BP Plus confers cytoprotection by maintaining mitochondrial homeostasis across structural, functional and transcriptional dimensions, providing mechanistic rationale for its clinical efficacy and highlighting mitochondrial protection as a therapeutic target in vital pulp therapy.
This in vitro study compared the accuracy and operative removal time of three dynamic navigation systems for fibre post removal using standardised 3D-printed tooth replicas. Forty-eight identical maxillary incisor replicas containing cemented fibre posts were randomly allocated to three navigation-guided groups and a freehand group (n = 12). Virtual drilling paths were planned from cone-beam computed tomography images, and all procedures were performed by a single operator. Pre- and postoperative micro-computed tomography scans were used to measure coronal, apical and angular deviation. All navigation-guided groups showed significantly lower apical and angular deviation than the freehand group, whereas no significant differences were observed among the three navigation-guided systems. Coronal deviation was similar across groups. One navigation system required significantly less operative removal time than the other groups without compromising accuracy. Within the limitations of this laboratory study, dynamic navigation improved the precision of fibre post removal compared with the freehand technique.
