Contemporary endodontic microsurgery has emerged as a significant treatment modality in the retention of teeth with persistent apical periodontitis. This article proposes the concept of the full-cycle clinical management of endodontic microsurgery based on the condition of the patient and tooth, attempting to develop a comprehensive strategy for the examination, treatment and follow-up to save natural teeth. Full-cycle clinical management included preoperative consideration of the general condition and surgical site and selection of cases for endodontic microsurgery; intraoperative application of techniques such as lasers, "bone window" technique and targeted endodontic microsurgery to make the surgical approaches more varied and the operation minimally invasive; postoperative outcome assessment according to the history, clinical and radiographic examination; and analysis of the short- and long-term outcomes.
Objective To investigate the effects of graphene on the proliferation, migration and cell morphology of dental pulp stem cells (DPSCs). Methods Graphene powder was prepared by the oxidation-reduction method, and a 0.5 mg/mL graphene dispersion was prepared. Raman spectroscopy and atomic force microscopy were used to characterize the structure and surface morphology of graphene. DPSCs were isolated and cultured in vitro. MTT assay was used to detect the effects of different concentrations of graphene dispersions (0, 1, 5, 10, 20, 50, 100 μg/mL) on the proliferation and wound healing assay was used to detected the migration abilities of DPSCs. The effects of graphene on the morphology of DPSCs were observed by immunofluorescence staining. Results In the present study, compared with the control group (0 μg/mL), the proliferation of DPSCs in the 100 μg/mL group was inhibited at 72 h (P < 0.05), and the proliferation of DPSCs in the other groups was not significantly affected (P > 0.05). Graphene dispersions at 10 and 20 μg/mL promoted the migration of DPSCs (P < 0.05). After being cultured in 20 μg/mL graphene dispersions for 3 days, the DPSCs showed a large and orderly cytoskeletal structure, and the spread area of cells was not significantly different from that of the control group (0 μg/mL) (P > 0.05), while some cells had the morphological characteristics of nerve cells. Conclusion Graphene has good biocompatibility and is expected to be a suitable material for tissue engineering within fitting concentration.
Objective This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique. Methods Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test. Results The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature. Conclusion With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.
Objective To explore the feasibility of antler powder/silk fibroin/polyvinyl alcohol scaffolds as tissue engineering bone scaffolds and the relationship between their degradation performance and the healing speed of bone defects. Methods Antler powder/silk fibroin/polyvinyl alcohol scaffolds and nano hydroxyapatite/silk fibroin/polyvinyl alcohol scaffolds were prepared by 3D printing. The whole bone marrow culture method was used to prepare blood cell sheets of Altay big tail sheep’s iliac bone marrow. With observation times of 1, 2 and 3 months, the mandibular defects of 4 sheep were established. The experimental group was coated with antler powder/silk fibroin/polyvinyl alcohol scaffolds. The control group was coated with nanohydroxyapatite/silk fibroin/polyvinyl alcohol scaffolds. The negative control group was coated with gel-free sponges. According to the self-control method of the bilateral mandible defect area, scaffolds wrapped with cell membranes or gel sponges wrapped with cell membranes were implanted. At the ends of the first, second and third months after implantation, the experimental animals were killed, cone beam CT was performed, and paraffin sections were taken for HE staining to evaluate the effect of different scaffold materials on bone regeneration and scaffold degradation. Results Scanning electron microscopy showed that both groups had regular pores and good continuity, and there was no difference in pore size and porosity between the two groups (P > 0.05). The results of CBCT imaging showed that in 3 months after operation, the experimental group had significantly better repair effects on bone defects than the control group, and the degradation rate matched the bone repair rate. The bone mineral density in the center of the defect was higher than that of the control group, which was close to that of normal bone tissue. The central bone mineral density of the experimental group at each time point was higher than those of the control group and the negative control group, and the difference was statistically significant (P < 0.05). HE staining results showed that the bone cells in the experimental group were more active, with more new capillaries and bone trabeculae formed, and the scaffold material absorbed more than the control group. Conclusion The antler powder/silk fibroin/polyvinyl alcohol scaffold can promote the repair of critical bone defects. Its degradability matches its bone tissue healing rate. It is expected to become a promising scaffold material for bone tissue engineering.
Objective To study the role of DNA methylation in oral leukoplakia carcinogenesis. Methods DNA methylation was detected in forty cases of oral squamous cell carcinoma (OSCC), twenty-eight cases of oral leukoplakia (OLK) and forty cases of healthy oral mucosa. Download the expression profile data of OSCC, OLK and healthy oral mucosa from Gene Expression Omnibus (GEO) database. DNA methylation data and expression profile data were compared for repeatability, DNA methylation data for difference analysis and corresponding expression profile data for IPA pathway analysis. Results The data analysis showed that DNA methylation had greater flexibility and instability. Ingenuity Pathway Analysis (IPA) analysis showed that genes related to OLK differential methylation sites were mainly concentrated in the process of cell movement and differentiation. Genes related to differential methylation sites of OSCC are mainly enriched in cell proliferation, migration, oxidation regulation, and anti-apoptosis processes. The genes associated with OLK and OSCC differential methylation sites are co-enriched in phosphoinositol metabolism and phospholipase C signaling pathway. Conclusion DNA methylation is involved in the formation of oral squamous cell carcinoma, and the activation of phosphoinositol metabolism may promote oral leukinoma.
Objective To evaluate the effects of root calculus residue and root cement preservation by ultrasonic subgingival scaling and root planing (SRP) with or without perioscopy. Methods Twelve teeth extracted due to severe periodontitis were randomly divided into three groups with four teeth in each group: ① Endoscope-assisted SRP group. The root surfaces of the affected teeth were cleaned with an EMS ultrasonic treatment instrument. ② Traditional SRP group. The affected teeth were treated by ultrasonic subgingival scaling and hand root planing with a Gracey curette. ③ Untreat group. The above operations were performed by the same senior physician. Under local anesthesia, each tooth was scraped for 10 minutes and then extracted. The residual amount of calculus on the root surface after plaque staining was observed and recorded. The thickness of the retained cementum at 1/3 of the root neck was measured. Results The residual rate of calculus on the root surface was the lowest in the endoscope-assisted SRP group, which was significantly different from the traditional SRP group and the untreated group (P < 0.001). Histological observation showed that the mean residual cementum thickness at 1/3 of the root neck increased gradually from the cemento-enamel junction (CEJ), 2.5 mm below the CEJ and 5 mm below the CEJ. Ultrasound SRP assisted by endoscopy caused less damage to the cementum and preserved the cementum better than traditional subgingival scaling (P < 0.001). Conclusion Compared with traditional SRP therapy, endoscope-assisted SRP treatment can remove subgingival plaque and calculus more effectively and can better preserve the cementum of the root surface.
Objective To evaluate the clinical effects of resin infiltration in treating molar-incisor hypomineralization. Methods Twelve patients (36 teeth) with mild molar-incisor mineralization imperfecta who met the inclusion criteria were selected and treated with penetrating resin. Before treatment (T0), at the one-week follow-up (T1) and at the six-month follow-up (T2), a Crystaleye spectrophotometer was used to take photos, and the color differences (ΔE) between the lesion area and the surrounding normal enamel area at different times were calculated and analyzed. The area of the lesion and the total area of the labial surface of affected teeth were calculated using Adobe Photoshop CS3 software. The corresponding area ratio (R) and treatment efficiency (SR) were obtained. The R value was used to judge the effectiveness of resin penetration in the treatment of molar and incisor mineralization imperfecta and to evaluate its aesthetic effect. The results were analyzed by repeated measures one-way ANOVA. Results The color difference of the lesion area vs sound adjacent enamel (ΔE) decreased significantly, and that of the lesion area decreased significantly after resin infiltration (P < 0.001). The success rate was approximately 86.02%, which means that the esthetic effect of resin infiltration in treating molar-incisor hypomineralization was remarkable. No important adverse events or side effects were observed. Conclusion The aesthetic effect of resin infiltration in the treatment of mild molar and incisor hypomineralization is good. This method is recommended for clinical use.
Objective To explore the key points of clinical diagnosis and treatment of three mesiobuccal root canals. Methods In the procedure of endodontic therapy for the upper left second molar with pulpitis, through root canal exploration under a dental microscope and cone beam CT (CBCT)-assisted imaging examination, it was confirmed that the left upper second molar contained 3 roots and 5 root canals, among which the third root canal existed in the mesiobuccal root. Combined with perfect root canal preparation, cleaning, disinfection, filling and minimally invasive inlay repair, the clinical symptoms were eliminated. The patients were followed up and the related literatures were reviewed. Results One- and two-year follow-ups showed that the tooth had no discomfort and could be used normally. X-ray revealed that the filling was complete, and the periapical tissue was normal. The results of the literature review showed that the incidence of three mesiobuccal root canals in maxillary second molars was 0.11%-4.2%. It is difficult to find additional root canals only by X-ray imaging. Dentists should further determine the number and anatomical shape of root canals by CBCT and operating microscopy. When there are three mesiobuccal root canals in maxillary molars, dentists should avoid overpreparation. Healthy tooth tissue is the key to good prognosis. Conclusion During root canal therapy, clinicians should consider the anatomical variation of the root canal, should always be alert to the existence of an extra root canal, and should use CBCT, operating microscopy, ultrasound and various auxiliary instruments to locate and treat the variant root canal.
Shared decision making (SDM) refers to two-way communication between doctors and patients. SDM helps surgeons decide the most suitable treatment plan for patients based on the medical evidence and the preferences of patients. A standardized clinical process and decision assistant tools, such as verbal tools, graphic tools, and patient decision aids, can help the shared decision-making work effectively. Since the sense of facial aesthetics is individual and there are multiple treatment options in plastic surgery, facial aesthetic surgery is suitable for the application of SDM. In addition, medical service centers can also meet the personalized needs of patients, provide high-quality medical services for patients and achieve better treatment results with SDM. SDM has not been introduced into the clinical practice of maxillofacial plastic surgery in China, and its development is facing many difficulties, such as the lack of decision aid tools, the limited time of diagnosis, and the lack of doctor-patient communication. Research and development of standard SDM clinical implementation path guides and decision aid tools will be beneficial to the application and development of SDM in the field of maxillofacial plastic surgery in China.
Head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor that seriously threatens human health and life. With increasing studies on the mechanism of tumor immune escape, programmed death receptor 1 (PD-1) and programmed death ligand receptor 1 (PD-L1) have been proven to be involved in tumor immune escape. The primary mechanism is that PD-1 recruits protein tyrosine phosphatase (SHP-2) to dephosphorylate downstream tyrosine kinase (SyK) and phosphatidylinositol 3-kinase (PI3K), thereby inhibiting downstream protein kinase B (AKT), extracellular regulated protein kinases (ERK) and other important signaling pathways, ultimately inhibiting T cell activation. In recent years, PD-1/PD-L1 inhibitors have become popular immunotherapies. Pembrolizumab and nivolumab have been approved for HNSCC patients by the U.S. Food and Drug Administration. Both durvalumab and atezolizumab are still in clinical trials, and published data show that both have certain safety and efficacy but still need much clinical data to support them. Meanwhile, the combination of PD-1/PD-L1 inhibitors with radiotherapy, chemotherapy and immunotherapy is still controversial in terms of clinical efficacy and adverse events, and further research is needed. However, serious immune-related adverse reactions limit the clinical application of PD-1/PD-L1 inhibitors, despite promising curative effects. Therefore, developing novel inhibitors and investigating stable and effective biomarkers and upstream and downstream signaling mechanisms are urgent issues.
Mandibular defects in adolescents are mostly caused by surgical resection of benign and malignant tumors, trauma and jaw inflammation. The reconstruction of mandibular defects in adolescents is challenging. In addition to solving the problem of jaw reconstruction in adults, some clinical factors, including the influence of surgery on the growth of donor and recipient areas, the long-term effects of reconstruction, and the outcome of bone grafts, must also be considered. At present, the main reconstructive methods include autogenous bone grafts and distraction osteogenesis. Autogenous bone grafts are still the gold standard due to their long-term effects. Favorable growth potential after repair was shown in adolescent cases of mandibular reconstruction with fibula flap. Normal occlusion was restored, and a long-term stable effect was achieved in cases of condylar reconstruction with costal cartilage. The safety and clinical effects of distraction osteogenesis have been confirmed, but the long-term effects of large-scale mandibular defects are still uncertain. In addition, other tissue engineering techniques also have good application prospects for the repair and reconstruction of adolescent mandible defects, but more in-depth basic research and more extensive clinical trials should be performed to verify the efficacy.
Minimally invasive endodontics (MIE) can preserve dental tissue to a greater extent and improve the success rate of endodontics and has thus attracted increasing attention. 3D printing is a technology that is based on a digital model and uses powdered metal, plastic and other materials to construct objects by printing layer by layer. This article reviews the application of 3D printing technology in minimally invasive endodontics to provide a reference for the application of 3D printing technology in clinical minimally invasive endodontics in the future. In recent years, 3D printing technology has been widely used in various professional fields of stomatology, such as maxillofacial surgery, prosthodontics, and orthodontics. Using cone beam computed tomography (CBCT) and oral scanners to obtain accurate data on the internal and external structures of teeth combined with 3D printing to construct a tooth diagnostic model and pulp opening guide plate, we can accurately locate the position of the root canal and provide a new method for minimally invasive endodontics. At present, 3D printing technology is mainly used to guide the pulp opening pathway, assist in the minimally invasive treatment of malformed teeth and calcified root canals, and assist with apical surgery in the field of minimally invasive endodontics. However, its accuracy and clinical prognosis still need to be verified with a large number of clinical cases.