20 October 2022, Volume 30 Issue 10

  • Select all
    Expert Forum
  • LIN Zhengmei, HE Yingcong, HUANG Shuheng, HUANG Qiting, ZHANG Xinfang, LIN Hongkun
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 685-691. https://doi.org/10.12016/j.issn.2096-1456.2022.10.001
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Endodontic microsurgery is a vital treatment modality for teeth with persistent periradicular pathoses that have not responded to nonsurgical retreatment. The principle is to determine the reason for failure, completely eliminate the infection and promote periapical healing. Within recent years, endodontic microsurgery has evolved to become standardized and presents with a high success rate. However, its outcome is still influenced by many factors, including anatomy, periodontal condition, crown-to-root ratio, occlusion, the type of periradicular lesion, and prosthesis. Moreover, endodontists always concentrate on “the apex”, paying little attention to the general preoperative evaluation, accurate diagnosis, and comprehensive treatment plan. This article reviews the latest literature on these issues and the clinical experience of our research group and discusses the correlation between endodontic microsurgery and other oral disciplines, including periodontology, prosthodontics, oral implantology, oral and maxillofacial surgery and orthodontics. The oral interdisciplinary assessment should be made with comprehensive consideration of the root canal system, periradicular lesion, adjacent anatomical relationships, periodontal condition, occlusion, and esthetic rehabilitation. Based on these findings, the continuity of treatment will be optimized, and the best treatment plan will be proposed to provide clinical strategies for the diagnosis and treatment of complex periradicular diseases.

  • Basic Study
  • XU Zhaoying, ZHANG Xue, PAN Shuang
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 692-698. https://doi.org/10.12016/j.issn.2096-1456.2022.10.002
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To observe the effect of dopamine pretreatment of the root canal on improving the bonding performance of AH-plus sealer. Methods A total of 32 freshly isolated permanent teeth with a single canal were collected, with no caries, no fracture of roots, and a root canal curvature<10°. All sample root canals were prepared to F2 with ProTaper rotating nickel-titanium instruments and then treated with 1 mg/mL, 2 mg/mL, or 3 mg/mL dopamine solution for 24 hours and divided into 4 groups (n = 8): 0 mg/mL dopamine group (blank control group), 1 mg/mL dopamine group, 2 mg/mL dopamine group, and 3 mg/mL dopamine group. Scanning electron microscopy was used to observe the combination of dopamine and root canal dentin wall; laser confocal scanning microscopy was used to observe the penetration of AH-plus sealer; and root canal filling was performed with AH-plus sealer and gutta-percha tip using the cold gutta-percha lateral pressure technique. The root canal samples were cut horizontally at the middle and the apical third sections of the root with a slice thickness of 1-2 mm. The push-out test was carried out under an Instron universal testing machine to compare the push-out bonding strength between each group. Results Scanning electron microscopy showed that most of the dentinal tubules were open in the control group after 0 mg/mL dopamine solution treatment for 24 hours. In the 1 mg/mL group, a small number of dopamine particles on the surface of the dentin tubules in the inner wall of the root canal were loose and unevenly distributed. In the 2 mg/mL group, most of the dentinal tubules were covered by dopamine particles, and the dopamine layer was uniform and dense. In the 3 mg/mL group, a large number of dopamine particles were deposited at the mouth of the dentinal tubules, but the distribution was uneven. Dopamine and AH-plus sealer can be seen to simultaneously infiltrate into dentinal tubules under a confocal laser scanning microscope. The interaction of the two factors, the anatomical location and dopamine concentration, had no significant effects on the bonding strength of AH-plus sealer (P>0.05). Root canals treated with 2 mg/mL dopamine had the highest bonding strength in all groups (P<0.05). Analysis of the push-out test of bonding strength with AH-plus sealer at different anatomical locations showed significant differences (P<0.05). The push-out bonding strength of the AH-plus sealer in the middle third section of the root was higher than that in the apical third section of the root. Conclusion Different dopamine concentrations could affect the bonding strength of AH-plus sealer in root canals. When treated with 2 mg/mL dopamine for 24 hours, the bonding effect of AH-plus sealer in root canals was improved.

  • ZENG Tian, CHEN Wenyuanfeng, ZHANG Guorui, LIU Yining, YANG Yanxia, CAO Baocheng
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 699-704. https://doi.org/10.12016/j.issn.2096-1456.2022.10.003
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To investigate the inhibitory effect of polydopamine (PDA) on enamel demineralization in isolated teeth and the induction of hydroxyapatite (HA) production on the surface of demineralized enamel to provide a novel protocol for the prevention and treatment of enamel demineralization. Methods Twenty isolated bovine teeth were cut into 20 enamel slices and randomly divided into an experimental group and a control group, with 10 slices in each group. The enamel slices in the experimental group were immersed in 2 mg/mL freshly prepared dopamine solution and incubated for 24 hours at room temperature in the dark to prepare the PDA coating, while the control group was left untreated. Then, the isolated bovine teeth, with and without PDA coating, were immersed in artificial demineralization solution at 37 °C for 3 days, followed by 7 days in simulated body fluid (SBF), and the immersion solution was changed daily. The surface morphology of enamel was observed by scanning electron microscopy (SEM), the calcium/phosphorus ratio of the enamel surface was analyzed by energy dispersive spectroscopy (EDS), and the characteristic functional groups in enamel deposits were analyzed by Fourier transform infrared spectroscopy (FTIR). Results Compared with the control group, the number of demineralized pores produced after 3 d of enamel demineralization with polydopamine coating was less, and the diameter was smaller. EDS elemental analysis showed that the Ca/P ratio after enamel demineralization was 2.37 in the experimental group, which was smaller than the 2.53 ratio in the control group. In the remineralization experiment, after 7 days of remineralization of PDA coated enamel in the experimental group, lamellar grains were produced on the enamel surface, and the growth showed obvious directionality, growth regularity and uniform arrangement. In the control group, the surface of enamel was flocculent mineral deposit, and the crystallinity was poor. The FTIR results proved that the enamel surface deposit of PDA-coated enamel was HA after 7 d of remineralization. Conclusion PDA can affect the nucleation process of HA and promote the production of HA on the surface of demineralized enamel.

  • CHENG Mingyang, QIAO Qin, LI Qun, LIAO Lan
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 705-711. https://doi.org/10.12016/j.issn.2096-1456.2022.10.004
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To investigate the antibacterial properties, biocompatibility and mechanical properties of Cu-ZnO-loaded dental veneering porcelain to provide an experimental basis for the development of new dental veneering porcelain. Methods Cu-ZnO nanoparticles were added to IPS E.max Ceram for restorative veneer porcelain at different mass percentages of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 6 wt% using ball milling in ceramic powder. A cylindrical specimen with a diameter of 20 mm and a thickness of 2 mm was prepared by high-temperature sintering. Scanning electron microscopy was used to observe the surface morphologies of nano-Cu-ZnO and the specimens. The antibacterial effect of Escherichia coli (E. coli) was quantitatively studied by the plate colony counting method. The CCK-8 method was used to evaluate in vitro the cytotoxicity of the tested piece to mouse fibroblasts (L929). Live and dead cells were observed by fluorescence microscopy. The mechanical properties of modified IPS E. Max Ceram veneering porcelain were tested by a three-point bending strength test. Results Under the scanning electron microscope, Cu-ZnO appears with a block-like structure and can be seen dispersed in the veneering porcelain. When the nano Cu-ZnO loading was 1 wt%, 2 wt%, 3 wt%, and 4 wt%, the antibacterial rates of the specimens were 24.85%, 67.94%, 96.92%, and 99.99%, respectively, and the difference between the experimental groups and the control group was statistically significant (F = 23.308,P = 0.001). The relative growth rate of each group was greater than 80% after coculture with mouse fibroblast cells (L929) for 1 day and 3 days, and there was no significant difference between the groups. The morphology of L929 cells was normal after coculture for 24 hours. With the increase in the Cu-ZnO concentration, the flexural strength of the specimen exhibited an increasing trend followed by a decreasing trend. The bending strength of the specimen loaded with 3 wt% nano Cu-ZnO reached the maximum value (84.728 ± 6.82) MPa, and there was no statistically significant difference between groups (F = 0.633,P = 0.702). Conclusion The antibacterial rate of IPS E. max Ceram veneering porcelain loaded with 3 wt% nano Cu-ZnO was more than 96% against E. coli after high-temperature sintering at 750 ℃. The bending strength reached the maximum (84.728 ± 6.82) MPa, and there was no obvious cytotoxicity.

  • Clinical Study
  • WANG Ruiyu, JIANG Nan, CAO Pinyin, LIU Yao, ZHU Songsong, BI Ruiye
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 712-717. https://doi.org/10.12016/j.issn.2096-1456.2022.10.005
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To generate a new classification for adult temporomandibular joint ankylosis (TMJA), which could effectively guide treatment strategies for adult TMJA patients with various clinical features. Methods We developed a new "CD" classification system according to the preservation of the condyle (C) and the severity of dentofacial bone deformity (D). From January 2016 to April 2020, 56 TMJ patients (with 73 ankylosed joints) in our department were classified into 4 subgroups by ‘CD’ classification: condylar head preservation but no dentofacial deformities (C+D-), no condylar head preservation and no dentofacial deformities (C-D-), condylar head preservation and dentofacial deformities (C+ D+), and no condylar head preservation but dentofacial deformities (C-D+). Different strategies were used according to the clinical features of each subgroup. The clinical outcomes of these patients were analyzed. Different treatment strategies of temporomandibular joint reconstruction were adopted for different subclasses of patients and were followed. "C +": lateral arthroplasty (LAP) was used to remove the rigidity and preserve the medial residual condyle. "C-": if the ankylosing bone ball is small and the loss of ascending branch height is not obvious, arthroplasty should be performed to relieve ankylosis; however, if the ankylosing bone ball is large and the ascending branch height decreases significantly, joint reconstruction should be carried out after the ankylosis is relieved. "D +": surgical treatment of secondary dental and maxillofacial malformations at the same time or over stages. "D-": orthodontic treatment after operation to improve occlusal relationship and symptomatic treatment of oral diseases. Results After treatment, all 73 ankylosed joints were completely released, and the average maximal interincisal opening increased from (3.6±3.2 )to (32.8 ± 5.4) mm (P<0.001), with no recurrence of ankylosis found during the 12-48 month follow-up period. Conclusion The generation and elaboration of a ‘CD’ classification system is intended to help as a TMJA reconstruction guide for adult TMJA treatment and be widely used in more hospitals.

  • LIU Yafei, WANG Yalin, DU Juan, ZUO Yanping, FENG Lifang
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 718-723. https://doi.org/10.12016/j.issn.2096-1456.2022.10.006
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To study the effect of anterior traction on the temporomandibular joint in adolescent patients with skeletal Class Ⅲ malocclusion. Methods Twenty-nine patients with early permanent dentition with skeletal class Ⅲ malocclusions were measured by cephalometry and a coordinate system before and after maxillary protraction. The correlation between dentofacial structures and the temporomandibular joint was analyzed. Results After maxillary protraction, cephalometric measurements showed that the dentofacial structure changed significantly; ANB increased by 3.97° ± 2.32° (P<0.001); U1-SN increased by 4.97° ± 5.51° (P<0.001); L1-MP decreased by 1.26° ± 1.41° (P = 0.008); and MP-SN increased by 1.02° ± 3.90° (P = 0.003). The coordinate system measurement showed that the S-Fpx was decreased by 0.16 ± 1.52 mm (P = 0.041), the S-Ciy distance was significantly decreased by 0.09 ± 2.03 mm (P = 0.028), and there was no significant change in the temporomandibular joint spaces (A, P, and C) (P>0.05). Correlation analysis showed a moderate negative correlation between the posterior margin of the temporomandibular joint fossa and U1-SN (r = -0.427, P = 0.042). There was a moderate positive correlation between the leading edge of the condyle and ANB (r = 0.425, P = 0.043); there was no correlation between the joint space and dentofacial changes. Conclusion After treatment with maxillary protraction for adolescent skeletal class Ⅲ malocclusion, maxillary protraction had some effect on changes in the temporomandibular joint fossa and condyle and had no effect on the joint space.

  • JIANG Xinke, YU Kang, ZHOU Mengqi, WU Yiqun, WANG Feng
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 724-732. https://doi.org/10.12016/j.issn.2096-1456.2022.10.007
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To detect WNT10A gene mutations in patients with oligodontia or anodontia (≥6 teeth missing) and analyze their dental phenotype. Methods Patients with oligodontia or anodontia were enrolled from the clinic for oral examination, genetic history collection and whole exon sequencing, and patients with WNT10A gene mutations were included. Sanger sequencing was utilized to validate the WNT10A gene variations in probands and family members compared with the normal sequence. The pathogenicity of WNT10A mutations was evaluated by functional prediction, conservation analysis and structure prediction of protein mutants. Implant rehabilitation was applied to restore the patients' oral function. Results Five WNT10A gene mutations were detected in six unrelated patients, and c.26G>A (p. Trp9X) and c.1036delT (p. Cys346fs) were novel mutations with pathogenic potential. The mean number of missing teeth was (15.33±8.64) per case. The most frequently missing permanent teeth were maxillary canines (100%), and the least frequently missing teeth were mandibular first molars (25%). Implant rehabilitation was applied in five patients, and patients were found to have ideal implant osseointegration and functional restoration. Conclusion This study identified novel WNT10A gene pathogenic variants, enriching the WNT10A gene spectrum and providing new evidence for genetic diagnosis and prenatal consultation. Implant rehabilitation was also proven to be a treatment option for these patients.

  • LIU Jingjing, WANG Jing, MAN Yi, QU Yili
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 733-739. https://doi.org/10.12016/j.issn.2096-1456.2022.10.008
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Objective To propose a digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate and explore its effect on vertical bone regeneration. Methods A total of 8 patients with severe vertical bone defects in the edentulous area who wanted to be treated with implants were included in this study. A digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate (fence technique) was used for bone augmentation. The patient's jaw, dentition, and soft tissue data were obtained for prosthetically guided implantation and bone regeneration. After virtual bone augmentation, a model of the jaw was obtained through 3D printing technology, and the titanium plate was bent accordingly. The virtual design was transformed through the template (including the base template and the attachment of a periosteal screw and bone block), so the actual osteogenesis space consistent with the design could be realized in the operation. Guided bone regeneration was performed according to the improved procedure and technical process. After 6 ~ 8 months of bone augmentation, cone beam CT was taken to evaluate the effect of bone augmentation. The implant was implanted according to the initial implant design, and bone tissue was obtained for HE and Masson staining. Results After 6 ~ 8 months of bone augmentation, the vertical linear bone increment reached (5.44 ± 1.73) mm. The implant was implanted according to the initial implant design, and the bone tissue was obtained for histological examination to show the formation of new bone. Conclusion Digital improved fence technique can simplify the preoperative and surgical procedures, and obtain good vertical bone augmentation results. In short, it is a kind of vertical bone augmentation technique worth popularizing and applying.

  • Review Articles
  • CHEN Jiajun, XUE Chaoran, WANG Peiqi, BAI Ding
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 740-745. https://doi.org/10.12016/j.issn.2096-1456.2022.10.009
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Root position plays an important role in healthy, stable, and aesthetic orthodontic treatment. In the past, two-dimensional radiographic images were used to assess the accuracy and precision of tooth root positions. In recent years, the use of cone beam CT (CBCT) and its reconstructed images to measure the three-dimensional spatial position and angle of root position has become mainstream. The root position is mainly described by measuring the relationship between the root and adjacent structures in the buccolingual, vertical, and mesiodistal directions as well as the root angle. The thickness of the alveolar bone on the buccolingual side of the root represents the buccolingual position, the vertical height in the alveolar bone and the relationship between apex and maxillary sinus represents the vertical position, the interroot alveolar bone thickness represents the mesiodistal position of the root, and the root angle is mostly based on incisal mandibular plane angle, angulation, torque, and other angles in the traditional two-dimensional measurement. Fitting CBCT and digital model data can be used to monitor the relationship between root and alveolar bone during orthodontic treatment, but a more comprehensive, standardized three-dimensional tooth root position measurement method is required to make full use of the root data provided by CBCT to study the relative optimal position of the tooth root at different anatomical levels, which combines with computer technology to optimize the digital design of orthodontic diagnosis and treatment.

  • HE Hongzhi, CHENG Lei, LI Bolei
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 746-750. https://doi.org/10.12016/j.issn.2096-1456.2022.10.010
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Head and neck squamous cell carcinoma (HNSCC) is a common tumor type. At present, surgical treatment, radiotherapy and chemotherapy are the main treatments for HNSCC, but these treatments have not achieved satisfactory results. The pH-sensitive drug delivery system is an environmental stimuli-responsive drug delivery system that utilizes the stimulation of environmental pH to produce corresponding changes in physical structure or chemical properties, thereby regulating drug release. This delivery system is the focus of the research field of drug delivery systems. At present, the drugs used in the pH-sensitive drug delivery system in the treatment of HNSCC include adriamycin, taxanes, 5-fluorouracil, and cisplatin, and have shown good stability, tumor targeting, and drug release controllability in preclinical studies. This demonstrates great value in clinical transformation. At present, the pH-sensitive drug delivery system faces issues such as difficulty in particle size control, low drug loading, and possible immune response reactivity. Therefore, the pH-sensitive drug delivery system is still being improved. This article reviews the theoretical basis and research progress of the pH-sensitive drug delivery system in the treatment of HNSCC.

  • ZHANG Yishuang, TAO Dihao, GUO Andi, ZHENG Hao, WANG Suping
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 751-756. https://doi.org/10.12016/j.issn.2096-1456.2022.10.011
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Glass ionomer cement (GIC) is widely used as a common filling material in dentistry but still exhibits problems with secondary caries and fractures. Thus, the antibacterial and anti-caries performance of GIC needs to be further improved. In recent years, natural antimicrobial components have become more desirable due to their good biological properties and low drug resistance. In this review, the natural antimicrobial ingredients in GIC modification are classified, reviewed and summarized according to the different sources of antimicrobial ingredients. In terms of animal origin, chitosan and casein phosphopeptide-amorphous calcium phosphate exhibit antimicrobial properties without affecting the mechanical properties of materials; propolis and bioactive enzymes have good biocompatibility; in terms of plant origin, polyphenols help improve the antimicrobial and mechanical properties of the material; arginine has a good remineralization effect; and plant essential oils have a certain ion release effect. In terms of microbial origin, antibiotics greatly improve the antibacterial properties of materials; in addition, the combined application of natural antimicrobial ingredients also exhibited excellent performance. Despite these advantages, the optimal addition concentration and biocompatibility in vivo are questions that need to be further explored before clinical applications can be achieved.

  • ZHANG Peipei, LI Hongyan, TIAN Yue, CHEN Huishan, LIN Hongbing, SHEN Yuqin
    Journal of Prevention and Treatment for Stomatological Diseases. 2022, 30(10): 757-760. https://doi.org/10.12016/j.issn.2096-1456.2022.10.012
    Abstract ( ) Download PDF ( ) HTML ( ) Knowledge map Save

    Basic fibroblast growth factor (bFGF) exhibits superior biological functions by improving periodontal inflammation, promoting the migration and proliferation of periodontal-related stem cells, promoting the formation of blood vessels and periodontal ligament-like tissue, and regulating the formation of bone/cementum. It plays an important role in tooth development, repair and regeneration. bFGF can be combined with seed cells and scaffold materials for periodontal tissue regeneration, which has been verified in a number of experimental studies. However, the application of bFGF alone as a drug in clinical treatment requires further research.