Objective To investigate the effect of programmed death-ligand 1 (PD-L1) on the aging process of dental pulp stem cells (DPSCs) and its regulatory mechanism, so as to provide a basis for optimizing the clinical application strategy of DPSCs. Methods Primary DPSCs were isolated and cultured by enzyme digestion method. Oxidative stress-induced senescence model was constructed by H₂O₂ induction, and a replicative senescence model was established by continuous subculture. The expression differences of PD-L1 in young and senescent DPSCs were detected by Western blot, RT-qPCR and immunofluorescence. High-efficiency PD-L1 interference sequences were screened to construct PD-L1 knockdown cell models. SA-β-gal staining, RT-qPCR and Western blot were used to detect the senescence phenotype of DPSCs and the expression of senescence-related markers such as P16, P21 and P53. The expression levels of odontogenesis/osteogenesis-related proteins such as DMP1, DSPP, and ALP were detected by Western blot, and further ALP staining was used to examine the effect of PD-L1 knockdown on the ALP activity of DPSCs. ROS detection and JC-10 staining were performed to evaluate the effect of PD-L1 on the oxidative stress level and mitochondrial function of DPSCs. Results Compared with young DPSCs, the mRNA and protein expression levels of PD-L1 in senescent DPSCs were significantly increased (P<0.01). After PD-L1 knockdown, the proportion of SA-β-gal positive cells was significantly reduced (P<0.001); the expression of P16, P21 and P53 was down-regulated (P<0.01); the expression levels of ALP, DMP1 and DSPP were significantly up-regulated (P<0.001); intracellular ROS accumulation was reduced (P<0.001); mitochondrial membrane potential was increased (P<0.001), and mitochondrial function was improved. Conclusion Knockdown of PD-L1 can effectively alleviate the senescence process of DPSCs and significantly promote their odontogenic/osteogenic differentiation potential; its regulatory mechanism may be closely related to reducing intracellular oxidative stress level and improving mitochondrial membrane potential.

Objective To analyze the effects of different clear aligner thicknesses and attachment designs on the distal movement of the maxillary canine using the three-dimensional finite element method. Methods Based on imaging data from a patient treated in the Department of Orthodontics, Stomatology Hospital, Zhejiang University School of Medicine in 2023, a three-dimensional finite element model was established simulating the extraction of the maxillary first premolar and distal movement of the maxillary canine. Nine groups (A-I) were created according to aligner thickness (0.70 mm, 0.75 mm, 0.80 mm) and attachment type (no attachment, vertical rectangular attachment, torque control attachment). Stress distribution in the tooth and periodontal ligament, as well as three-dimensional displacement trends of the canine, were analyzed. Results Stress distribution was relatively uniform in all models without significant concentration. The canine exhibited distal tipping movement accompanied by palatal and intrusive displacement. Under the same attachment condition, the 0.75 mm aligner achieved the greatest distal movement. With the same aligner thickness, the torque control attachment group showed the smallest tipping angle, while the vertical rectangular attachment group achieved greater distal movement and optimal vertical control. The no-attachment group exhibited the largest displacement in both buccolingual and vertical directions. Conclusion The 0.75 mm thick aligner demonstrated the most sufficient displacement expression and the highest achievement rate of distal movement. Adding attachments significantly improved the efficiency of bodily tooth movement. Movement under the torque control attachment was closest to pure translation, while the vertical rectangular attachment provided a higher rate of distal movement and better vertical control.

Objective To investigate the role of activating transcription factor 6(ATF6) in macrophage-mediated periodontal inflammation and alveolar bone resorption. Methods An inflammation model was established by stimulating RAW264.7 cells with lipopolysaccharide (LPS). RT-qPCR was used to detect changes in the expression of inflammatory factors and ATF6. The function of ATF6 was further validated using siRNA knockdown. Macrophage-specific ATF6 knockout mice(ATF6^fl/fl; Cx3cr1^CreERT2) were generated. Experimental periodontitis was induced using the silk ligature method. Alveolar bone resorption and inflammation levels were evaluated by Micro-CT, HE staining, and bone morphometric analysis. Results As shown in experiments, LPS stimulation significantly upregulated ATF6 expression in macrophages and markedly increased the level of inflammatory. Knockdown of ATF6 significantly inhibited the expression of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α in LPS-induced macrophages. Consistently, studies demonstrated that macrophage-specific deletion of ATF6 notably attenuated alveolar bone loss induced by periodontitis and improved the bone volume fraction(BV/TV). Conclusion Macrophage-derived ATF6 plays a critical pro-inflammatory role in the progression of periodontitis. Reduction of its expression attenuates inflammatory responses and alveolar bone resorption.

Objective To explore the effects of antimicrobial peptides on the levels of periodontal inflammatory factors and bone metabolism factors in gingival crevicular fluid of patients with periodontitis. Methods A total of 108 patients with stage Ⅲ periodontitis in Department of Xinghai, Suzhou Stomatological Hospital were randomly divided into a control group, a minocycline group and an antimicrobial peptide group, with 36 patients in each group. The control group was given iodine glycerol in the periodontal pocket immediately and one week after scaling and root planing; the minocycline group was given minocycline hydrochloride, and the antimicrobial peptide group was given biological antimicrobial peptides. The differences in periodontal status (bleeding index (BI), probing depth (PD), attachment loss (AL)) between groups before and 30 d after treatment were compared through clinical examination. The inflammatory factors (matrix metalloproteinase-9 (MMP-9), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α)) and bone metabolism indicators (alkaline phosphatase (ALP), bone γ-carboxyglutamic acid-containing protein (BGP), osteoprotegerin (OPG), SP7) in gingival crevicular fluid between three groups before and after treatment were compared through enzyme-linked immunosorbent assay (ELISA) detection. Results Before treatment, there were no statistically significant differences in periodontal indices (BI, PD, AL), inflammatory factors (MMP-9, IL-1β, TNF-α), and bone metabolism factors (ALP, SP7, BGP, OPG) among the three groups (P>0.05). Thirty days after treatment, all three groups showed significant improvement in various indicators compared to before treatment (P<0.05), and the indicators of the minocycline group and antimicrobial peptide group were better than those of the control group (P<0.05). In addition, the improvement of periodontal index BI, PD, and AL in the antimicrobial peptide group was better than that in the minocycline group (P<0.05); MMP-9, IL-1β were significantly lower in the antimicrobial group than in the minocycline group (P<0.05); ALP, SP7, BGP and OPG bone metabolism indicators were significantly higher than those in the minocycline group (P<0.05), but there was no significant difference in TNF-α levels between the two groups (P>0.05). Conclusion Biological antimicrobial peptides are significantly superior to minocycline hydrochloride in reducing periodontal inflammation and improving bone metabolism, and have potential for application as oral topical drugs for the treatment of periodontitis.

Objective To investigate the regulatory effect of T-box transcription factor 1 (TBX1) on the osteogenic differentiation capacity of human dental pulp stem cells (hDPSCs) and its underlying mechanism. Methods In vitro, a TBX1-knockdown hDPSCs model was constructed using lentiviral transfection. Alkaline phosphatase (ALP) staining was performed to assess early osteogenic differentiation, and alizarin red S (ARS) staining was used to observe mineralized nodule formation at the late stage. The expression levels of osteogenic markers including collagen type Ⅰ (COL1), osterix (OSX), and Runt-related transcription factor 2 (RUNX2) were detected by Western blot and RT-qPCR. Conditioned medium collected on day 7 of osteogenic induction was used for tube formation assay with human umbilical vein endothelial cells (HUVECs), and the mRNA expression levels of vascular endothelial growth factor A (VEGFA), angiopoietin-1 (ANG1), and platelet-derived growth factor subunit B (PDGFB) were detected by RT-qPCR. In vivo, an ectopic osteogenesis model was established in nude mice by subcutaneous implantation on the dorsum. The mice were randomly divided into control group (consh) and TBX1 knockdown group (TBX1sh), which received composites of HA/TCP scaffolds seeded with hDPSCs transfected with consh or TBX1sh, respectively. HE staining was performed to compare the differences in new bone formation between the control and TBX1 knockdown groups. Immunohistochemi-cal staining was conducted to detect the expression of osteogenesis-related proteins, including RUNX2, osteocalcin(OCN), bone sialoprotein(BSP), and platelet endothelial cell adhesion molecule (CD31). Results In vitro experiments showed that TBX1 knockdown significantly enhanced ALP activity, mineralized nodule formation, and the expression of osteogenic differentiation markers (COL1, OSX, RUNX2) in hDPSCs(P<0.05). Additionally, the mRNA levels of VEGFA, ANG1, and PDGFB were significantly upregulated (P<0.05), and the conditioned medium from TBX1-knockdown hDPSCs markedly promoted the formation of tubular structures in HUVECs (P<0.05). In vivo results demonstrated increased new bone formation and upregulated expression of osteogenic-related proteins in the TBX1-knockdown group (P<0.05). CD31 immunohistochemical staining showed that both microvessel density and integrated optical density were significantly higher in the TBX1-knockdown group compared to the control group (P<0.05). Conclusion TBX1 is a negative regulator of osteogenic differentiation in hDPSCs. Knockdown of TBX1 effectively promotes the osteogenic differentiation of hDPSCs, and the underlying mechanism may involve enhanced pro-angiogenic capacity and improved local microenvironment.

Objective To investigate the accuracy and clinical efficacy of a novel strategy—zigzag scanning guided by marking lines—in the fabrication of direct digital custom trays for maxillary edentulous jaws. Methods An ex vivo experiment and a clinical trial were carried out. The ex vivo experiment selected a standard maxillary edentulous model and was comprised of a reference model group(RM), a control model group (CM), and an experimental model group(EM). The clinical trial was comprised of a conventional impression group(CP), an indirect digital impression group(IP), and an experimental direct digital impression group(EP). The experimental groups employed marking lines combined with a zigzag scanning path to acquire digital preliminary impression data. Three-dimensional deviation analysis was used to compare trueness and precision among groups, while a visual analog scale assessed clinicians’ satisfaction with the custom trays. Results In the standard model, the EM group demonstrated significantly superior trueness compared to the CM group(P<0.05), with no significant difference in precision. In the clinical trial, the EP group showed significantly better trueness for preliminary impressions than the IP group(P<0.05), with final impression quality comparable to the CP group. Clinician satisfaction evaluations revealed that both the IP and EP groups scored significantly higher than the CP group in border molding, and the EP group received the highest score in overall satisfaction(P<0.05). Conclusion The zigzag scanning guided by marking lines effectively improves the accuracy of direct digital preliminary impressions for maxillary edentulous jaws, enhances border adaptation of custom trays, and increases clinical operational satisfaction, demonstrating promising clinical applicability worthy of widespread adoption.

Objective To investigate the correlation between three-dimensional upper airway morphology and temporomandibular joint (TMJ) structural characteristics in skeletal Class Ⅱ malocclusion patients with different vertical skeletal patterns. Methods Thirty-six adult patients with skeletal Class Ⅱ malocclusion who attended the Department of Orthodontics at our hospital between January 2021 and December 2024 were enrolled and divided into hypodivergent, normodivergent and hyperdivergent groups according to vertical skeletal pattern. All patients underwent CBCT examination. Three-dimensional airway reconstruction was performed using Dolphin Imaging 11.9 software. The volumes of the nasopharynx,velopharynx,glossopharynx, laryngopharynx as well as the minimum cross-sectional area of the oropharynx were measured. TMJ measurements included mediolateral condylar diameter, anteroposterior condylar diameter, condylar length, glenoid fossa width, glenoid fossa height and the sagittal position of the condyle within the fossa. The anterior and posterior joint spaces were recorded, and a linear ratio (LR) was calculated. One-way ANOVA was performed using SPSS 26.0 to compare intergroup differences; Pearson correlation analysis was used to evaluate the relationship between upper airway dimensions and TMJ structural parameters. Results Significant differences were found among the three groups in nasopharyngeal, velopharyngeal and glossopharyngeal airway volumes, as well as in the minimum cross-sectional area of the oropharynx (P<0.05). A decreasing trend from the hypodivergent group to the hyperdivergent group was observed. Significant intergroup differences were also found in anteroposterior condylar diameter and condylar length (P< 0.05). Correlation analysis showed that airway volumes were negatively correlated with the LR in both the hypodivergent and hyperdivergent groups. Conclusion CBCT-based findings indicate a correlation between TMJ morphological characteristics—particularly condylar position—and upper airway structure. Evaluation of condylar position should therefore be considered when assessing the airway during orthodontic treatment planning for patients with skeletal Class Ⅱ malocclusion.

Objective To investigate the effects of ferrous gluconate, both alone and in combination with conventional antifungal agents, on Candida albicans (C. albicans) biofilms and its drug resistance. Methods Experiments were conducted using standard strains and drug-resistant strains of C. albicans. Both the planktonic and biofilm states of the respective strains were cultured and established. C. albicans was treated with ferrous gluconate alone and in combination with antifungal drugs. The inhibitory effects were assessed using the XTT reduction assay and the checkerboard microdilution method respectively, while the time-kill curve tests were conducted to determine the kinetic effect of drugs on biofilm sterilization. The morphological changes of biofilms were observed under scanning electron microscopy (SEM). Results Ferrous gluconate exhibited inhibitory effects on both planktonic and biofilm states of standard strains and drug-resistant strains of C. albicans. The minimum drug concentration that inhibited 50% activity (SMIC₅₀) of biofilms was 50 mmol/L for both the standard and drug-resistant strains. A synergistic antifungal effect was observed when ferrous gluconate was combined with fluconazole. The time-kill curves for ferrous gluconate alone and in combination with fluconazole demonstrated that its inhibitory effect on the biofilms of both strains showed an overall trend of enhancement with the prolongation of time or the increase of dose, and the combination group exhibited a significantly stronger inhibitory effect compared to any agent used alone. Morphological observations revealed that both ferrous gluconate alone and in combination with antifungal drugs could reduce hyphal formation and biofilm-forming capacity of C. albicans. Conclusion Ferrous gluconate exerts an inhibitory effect on biofilms in both standard strains and drug-resistant strains of C. albicans and can reduce its drug resistance. The combination of ferrous gluconate and fluconazole demonstrates a synergistic antimicrobial effect.

Objective To explore anesthetic management strategies for patients with bipolar disorder undergoing impacted tooth extraction, and to review the literature regarding perioperative risks and corresponding management approaches. Methods A case of a 22-year-old male diagnosed with bipolar disorder(current depressive episode with mixed features)who underwent extraction of maxillary impacted teeth under general anesthesia was reported. A multidisciplinary evaluation was conducted preoperatively, and an individualized anesthesia plan was developed, focusing on avoiding drug interactions between psychiatric medications and anesthetics. General anesthesia was maintained with sevoflurane inhalation combined with intravenous agents, and BIS monitoring was applied. Postoperative care emphasized emotional stabilization and adequate analgesia. Results The patient’s vital signs remained stable during surgery without significant adverse events. Postoperative recovery was uneventful, with stable mood and satisfactory wound healing. Conclusion For patients with bipolar disorder undergoing oral surgery, their long-term medication history and psychological characteristics must be integrated into anesthetic assessment and perioperative planning. Rational selection of anesthetic agents and enhanced perioperative monitoring and support can improve surgical safety and clinical outcomes. This study further summarizes key points of anesthetic management in such patients through a literature review.

Lysosomes are essential organelles for maintaining periodontal tissue homeostasis, and their dysfunction plays a critical role in the initiation and progression of periodontitis. In periodontitis, a persistently acidic microenvironment, continuous pathogenic stimulation, and excessive inflammatory responses can induce multi-level lysosomal dysfunction, including impaired lysosomal acidification, disrupted autophagic flux, and compromised membrane stability. These alterations subsequently affect pathogen clearance, immune regulation, and bone metabolic homeostasis, thereby promoting inflammatory cascade amplification and alveolar bone destruction. This review aims to summarize recent advances in research on the roles of lysosomes and their dysfunction in periodontitis, with the goal of providing new perspectives and a theoretical basis for a deeper understanding of the molecular mechanisms and pharmacological interventions of this disease.

To explore the current applications, existing challenges, and future prospects of artificial intelligence (AI) in pediatric dentistry. Deep learning models have demonstrated a diagnostic performance in certain dental imaging-related diseases that is statistically comparable to expert assessments. Intelligent oral hygiene devices are now capable of generating personalized cleaning strategies. Deep learning techniques have also shown strong potential in caries risk prediction and dental age estimation. Moreover, AI exhibits unique applications in managing pediatric dental anxiety, pain control, and orthodontics. Nevertheless, several challenges remain, including issues related to data quality, volume, and management, as well as concerns involving medical ethics and legal regulations. Future efforts should emphasize enhancing data quality, optimizing algorithms, establishing robust ethical and regulatory frameworks, and strengthening research on AI-assisted treatment and clinical training.

Condylar fractures in children account for a high proportion of mandibular fractures. As the growth and development center of the mandible, condylar fractures, if not promptly treated, can easily lead to complications such as limited mouth opening, joint area pain, joint ankylosis, and facial asymmetry. Currently, there is no consensus on the treatment methods for condylar fractures in children. Non-surgical treatment is often the preferred treatment option due to its minimally invasive nature. However, with the development of medical technology, especially the improvement of minimally invasive techniques and bone grafting materials, surgical treatment for condylar fractures has gained significant acceptance among pediatric surgeons. The choice between the two treatment methods still requires extensive clinical observation. This article reviews different treatment options for condylar fractures in children and their advantages and disadvantages, taking into account the physiological characteristics of the condylar process in children, aiming to provide reference for the choice of treatment.

In recent years, with the rapid development of stomatology, oral implant has become the preferred restoration method of missing teeth. Infrared optical positioning dynamic navigation technology is a new type of oral implant treatment, which is accurate, safe, minimally invasive and predictable. Cone beam computed tomography (CBCT) plays an indispensable role in the dynamic navigation-guided implant surgery. This article reviews the preoperative planning, intraoperative application, postoperative review and precautions of CBCT in dynamic navigation implant technique.