Dental implantology has developed rapidly for over half a century, since pure titanium(99.7%) dental cylindrical threaded implants were exploited and osseointegration was introduced in 1960s by Prof. Brånemark. The long term retention rates of 10 years or more are over 95%. However, the biological complications jeopardize the long term effects of dental implant treatment seriously. The prevalence of dental implant biological complications varies greatly among different reports resulting from the disparities on the definitions of dental implant biological complications. After analyzing and summarizing the major opinions proposed internationally in recent years, the consensus for the definition of dental implant biological complications has been reached. Generally the dental implant biological implications can be classified into early stage(before restoration) biological complications and late stage(after restoration) biological complications. The early stage biological complications include acute and chronic infections, pain, soft tissue deficiency, and osseointegration failure, etc. The late stage complications include peri-implant diseases(peri-implant mucositis and peri-implantitis), soft tissue deficiency around implant, implant loosening and dropping off, etc. The various risk factors related to different dental implant biological complications, the strategies of the prevention and treatment for the dental implant biological complications have been discussed comprehensively, and the consensus has been reached. It is aimed to advocate the dentist to pay more attention to the early prevention of the biological implant complications, to promote more researches on the implant biological complications, and to help elevate the level of dental implantology in our country.

Objective To explore the association between the growth condition of mandibular third molars(M3) and the parameters of mandibular dental arch through a retrospective cross-sectional study on M3 in adults, and to provide a basis for the selection of clinical treatment of M3. Methods A total of 221 adult patients were randomly selected for our study. Dolphin software was used to analyze the CBCT of all the patients. Parameters of the mandibular dentition including the entire dental crowding(EDC) were recorded. Then the association between M3 growth condition and these parameters was analyzed. Results The mesio-impacted angle of M3 was positively correlated with EDC(P<0.05), and negatively correlated with the retromolar space(RMS, P<0.01). It was worth noting that median mesio-impacted M3 significantly increased EDC(P<0.01), and the erupting M3 in the vertical orthotopic position significantly increased RMS(P<0.01). Conclusion For patients with median mesio-impacted M3 or insufficient RMS, preventive removal of M3 may be considered clinically, which may help to reduce crowding and prevent relapse after orthodontic treatment.

Objective To compare the periodontally accelerated osteogenic orthodontics(PAOO) effects of corticotomy with full mucoperiosteal flap(flapped corticotomy) and corticotomy-only on accelerating orthodontic tooth movement. Methods A total of 60 healthy male SD rats(weighing 180-200 g)were selected and randomly divided into three groups. There were 20 rats each in the flapped corticotomy group, the corticotomy-only group, and the control group. After applying orthodontic instruments, 5 rats each in the surgical group and the control group were killed by excessive anesthesia on 0, 1, 3, and 7 days after tooth movement. The tooth movement distances of the rats in the control group and the experimental group were counted, and immunohistochemical staining was performed to observe the corresponding molecular biological changes. Results There was no significant difference in accelerating orthodontic tooth movement between the flapped corticotomy group and the corticotomy-only group. Compared with traditional orthodontic tooth movement, both the flapped corticotomygroup and the corticotomy-only group could bring an increase in the expression of RANKL on the pressed periodontal side while there was no significant difference between the two experimental groups. Both the flapped corticotomy and non-flapped corticotomy could enlarge the area of tissue formation in the periodontal tension zone, and still there was no significant difference between the two surgical methods. Compared with traditional orthodontic tooth movement, both the flapped corticotomy group and the corticotomy-only group could lead to an increase in ALP, OCN and OPN expression on the periodontal tension zone. Conclusion Both flapped corticotomy and corticotomy play a significant role in accelerating orthodontic tooth movement and promoting alveolar bone formation in the early stage. Both surgical methods of PAOO can provide more efficient and stable biological support for orthodontic treatment.

Objective To investigate the clinical phenotypic characteristics of a pedigree with congenital tooth agenesis (CTA) and identify the pathogenic gene using whole-exome sequencing (WES), aiming to confirm the disease-causing mutation site, explore its potential impact on protein structure and function, and provide new insights for the diagnosis of CTA. Methods The study focused on a pedigree with congenital absence of premolars. Blood samples were collected from pedigree members, and genomic DNA was extracted. Potential pathogenic mutations were screened using WES and bioinformatics analysis. Candidate mutations were validated by Sanger sequencing. Gene Ontology (GO) functional annotation and KEGG pathway enrichment analysis were performed on co-expressed genes of the candidate gene. Results Clinical examination revealed that all four members of the family were patients with missing premolar teeth. WES identified two novel mutations in the TTN gene (c. 94145G>A and c. 105406C>T) in all affected family members. Sanger sequencing confirmed co-segregation of these mutations with the disease phenotype in the pedigree. Bioinformatics analysis indicated that Ttn was highly expressed during craniofacial development in mouse embryos. Enrichment analysis demonstrated that Ttn co-expressed genes were significantly enriched in the extracellular matrix (ECM) receptor interaction and PI3K/Akt signaling pathway. Conclusion This study suggests that TTN is a potential pathogenic gene for congenital premolar agenesis in this pedigree.

Objective To explore the effects of glycyrrhizic polysaccharide(GP) on the biological activity of salivary adenoid cystic carcinoma tumor cells and its mechanisms of anti-tumor action. Methods GP was prepared, and human adenoid cystic carcinoma high-metastatic cell line SACC-LM and low-metastatic cell line SACC-83 were used as target cells. Different concentrations of GP were used for intervention. The cell counting kit-8 (CCK-8) assay was employed to detect cell proliferation and apoptosis. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot experiments were conducted to detect the expression of genes and proteins related to tumor invasion and metastasis. The scratch assay was used to observe the effect of GP on the migration ability of SACC cells. In vivo experiments were conducted to verify the inhibitory effect of GP on tumor cells. Results Glycyrrhiza polysaccharides significantly inhibited the proliferation and migration of the highly metastatic human adenoid cystic carcinoma cell line SACC-LM by regulating the expression of epithelial-mesenchymal transition (EMT)-related markers. In vivo experiments showed that glycyrrhiza polysaccharides had no significant hepatotoxicity, could significantly reduce the volume and weight of tumors, and inhibit the growth rate of tumors in nude mice. Conclusion GP has a certain inhibitory effect on the growth and migration ability of SACC.

Objective To compare the biomechanical characteristics of small-angle rotation force versus traditional buccal-lingual force in the extraction of vertically impacted mandibular third molars with single conical roots by a three-dimensional finite element analysis. Methods A patient with a vertical mandibular third molar featuring a conical single root was selected. Spiral CT data were acquired and three-dimensional finite element analysis models were constructed using software including MIMICS, Geomagic Wrap, and Solidworks. ANSYS was utilized to simulate both the small-angle rotation and buccal-lingual forces for tooth extraction. Comparative analyses of the biomechanical characteristics of these two forces were conducted by measuring Von-Mises stress and strain distribution. Results In the small-anglerotation force, high-stress and strain areas of tooth, periodontal ligament, and alveolar bone were predominantly concentrated at the cervical region and the upper half of the root, with a more uniform distribution and a broader horizontal diffusion range compared to the vertical diffusion range. In the buccal-lingual force, high-stress and strain areas were primarily located at the cervical region and the lower half of the root, particularly at the apical area, with a broader vertical diffusion range compared to the horizontal diffusion range. The lingual cortical plate and alveolar bone experienced significantly lower stress in the small-angle rotation force than that in the buccal-lingual force. The overall stress values within the periodontal ligament were markedly higher in the small-angle rotation force, with a more uniform distribution. Conclusion The small-angle rotation force is more likely to tear the periodontal ligament and reduce trauma associated with tooth extraction compared to the buccal-lingual force in surgical extraction of vertically impacted mandibular third molars with single conical roots.

Objective To analyze the anatomical relationship between maxillary premolars and the alveolar bone and maxillary sinus using cone-beam computed tomography(CBCT), in order to provide an anatomical basis for immediate implant placement in maxillary premolars. Methods Data from 351 patients who underwent maxillary CBCT imaging at Yancheng Stomatological Hospital between January 2022 and December 2023 were collected. Measurements included the vertical distance between premolar roots and the maxillary sinus floor, intraosseous root length, angle between the tooth axis and alveolar bone axis, and buccal/palatal bone wall thickness, with comparisons of gender differences. Results The median vertical distance between single-rooted maxillary first premolars and the maxillary sinus floor was 10.16 mm, while that for second premolars was 4.61 mm. For double-rooted first premolars, the buccal root distance was (4.13±3.99)mm and the palatal root was (5.14±3.94)mm. Maxillary first premolars were farther from the maxillary sinus floor than maxillary second premolars, with palatal roots farther than buccal roots. The intraosseous root length of maxillary first premolars was (9.20±1.44)mm, and maxillary second premolars (9.64±2.04)mm. Maxillary first premolars exhibited significantly shorter intraosseous root length than maxillary second premolars. The angle α between tooth axis and alveolar bone axis was 18.89°±6.33° for maxillary first premolars, and 12.65°±6.10° for maxillary second premolars, showing statistically significant differences. The buccal bone wall thickness of maxillary first premolars gradually decreased from 2 mm subcrest to the apex, while palatal bone walls of maxillary first premolars and both buccal/palatal walls of maxillary second premolars progressively thickened from 2 mm subcrest to the apex. Significant correlations were identified between angle α and buccopalatal bone wall thickness at mid-root and the apex: increased α corresponded with reduced buccal wall thickness and enhanced palatal wall thickness. Conclusion The apical region of maxillary first premolars provides sufficient bone volume for primary stability in immediate implantation, though the thin buccal bone wall necessitates careful consideration of implant shape and positioning. Maxillary second premolar roots are closely adjacent to the maxillary sinus floor, requiring implant stabilization with the sinus floor cortical bone or mesiodistal walls of the extraction socket.

Objective To investigate the effects and molecular mechanisms of ginsenoside Rg1 (GSRG1) on the proliferation, migration, and inflammatory cytokine expression of human gingival fibroblasts (HGFs) induced by lipopolysaccharide (LPS). Methods HGFs were isolated and cultured using the tissue block method. The effects of different concentrations of LPS (0, 1, 5, 10, 20 μg/mL) on inflammatory cytokines in HGFs were detected by ELISA. Cells were divided into three groups: control group (no treatment), LPS group (20 μg/mL LPS), and LPS+GSRG1 group (20 μg/mL LPS and 100 mg/L GSRG1). Cell proliferation was detected by cell counting kit-8 (CCK-8); cell migration was assessed by Transwell assay; intracellular reactive oxygen species (ROS) levels were compared using flow cytometry; and the expression levels of TNF-α, IL-6, NLRP3, p-p38, and p38 proteins were detected by Western blot. Results LPS concentrations of 5, 10, and 20 μg/mL significantly increased the expression of IL-6 and TNF-α in HGFs (P<0.05), with 20 μg/mL showing the strongest pro-inflammatory effect. Compared with the control group, there was no notable difference in the proliferation of HGFs in the LPS group at Day 1 and 2. However, on Day 3, 4 and 5, decreased cell proliferation, reduced migration, significantly increased ROS levels (P<0.001), elevated protein expression of TNF-α, IL-6, and NLRP3 (P<0.001), and reduced p-p38 protein expression (P<0.001) were exhibited. Compared with the LPS group, the LPS+GSRG1 group showed significantly enhanced cell proliferation and migration (P<0.05), reduced ROS levels, decreased protein expression of TNF-α, IL-6, and NLRP3, and increased p-p38 protein expression (P<0.001). There was no significant change in p38 expression among the three groups. Conclusion GSRG1 can alleviate the inhibitory effects of LPS on the proliferation and migration of HGFs and inhibit the inflammatory response, potentially through mechanisms involving p-p38 protein regulation.

Objective To evaluate the inhibitory effect of Lactobacillus plantarum mouthwash on the progression of caries in isolated teeth. Methods Human isolated teeth were infected with Streptococcus mutans solution, and treated with saline, commercial mouthwash, and Lactobacillus plantarum mouthwash, respectively, for 28 days. Tooth changes were recorded to assess their inhibitory effect on caries progression by light microscopy and scanning electron microscopy. Results Lactobacillus plantarum had an inhibitory effect on caries progression,with significant effects on deep dentinal caries in pit and fissure, and similar efficacy to commercial mouthwash on smooth surface caries. Calcium loss in dentin tubules was observed under an electron microscope, with Lactobacillus plantarum group less than commercial group and saline group. Conclusion Lactobacillus plantarum mouthwash can inhibit the growth of Streptococcus mutans and effectively prevent caries, particularly in controlling the progression of deep pit and fissure caries.

Objective To analyze the therapeutic effect of ultrasound combined with external application of Chinese medicine in the treatment of temporomandibular disorders(TMD). Methods A total of 72 patients with TMD and treated in our hospital from January 2022 to December 2023 were randomly divided into the control group and the treatment group, with 36 cases in each group. The control group was treated with ultrasound, and the treatment group was treated with ultrasound combined with traditional Chinese medicine. Then the pain VAS score, maximum mouth opening degree, joint click and clinical effect were observed before and after treatment. Results The VAS score of the treatment group was lower than that of the control group(P<0.05). There were more patients with maximum mouth opening greater than 3.7 cm in the treatment group than in the control group(P<0.05). There was no statistical significance in the number of patients with joint click between the two groups(P>0.05). The significant efficiency of treatment group was higher than that of control group(P<0.05). The effective rate of treatment group was higher than that of control group, but the difference was not statistically significant (P>0.05). Conclusion Ultrasound combined with external application of traditional Chinese medicine in the treatment of TMD, compared with single ultrasound treatment, can significantly improve the clinical symptoms and promote the clinical therapeutic effect.

Objective To investigate the different biomechanical effects of two types of palatal expanders and expansion sites on a bilateral complete cleft lip and palate (BCCLP) in mixed dentition with a finite element analysis (FEA). Methods The CBCT data of a patient with BCCLP were collected to construct a FEA model containing craniomaxillary suture structure. The fan-shaped and traditional Hyrax expanders were drawn and assembled into the FEA model in SolidWorks software according to the working conditions as follows: condition 1 and 2, the fan-shaped expander was placed at the anterior/posterior part of the palate respectively;condition 3 and 4, the Hyrax expander was placed at the anterior/posterior part of the palate respectively. A 5 N force in X axis direction was loaded at the apex of the expander coil spring. The stress distribution and initial displacement of craniomaxillary complex in four working conditions were compared. Results ①In working condition 1, 2 and 3, the displacement of anterior part was larger than the posterior part of the dental arch. Under condition 4, the displacement of anterior, middle and posterior parts of dental arch were basically the same. ②The maximum stress and displacement were observed at crowns in all working conditions. ③There was a certain skeletal enlargement effect, which showed a gradually decreasing deformation trend from alveolar region to the upward region. Conclusion The expansion effect of fan-shaped expander is more suitable for BCCLP patients with extremely narrow anterior arch and normal posterior arch. For the traditional Hyrax expander, the position has a great influence on expansion effect. It is showed that the dental support expander could produce skeletal dilation effect in BCCLP patients during mixed dentition.

Recent advances in vital pulp therapy(VPT)research, coupled with the widespread use of biomaterials, have led to an increase in the application of VPT. The indications for VPT are continually expanding, particularly for fully developed permanent teeth. Currently, one-way membrane decompression is being investigated as a possible treatment to preserve vital pulp in cases of irreversible pulpitis. This technology involves creating an access point in the pulp cavity and using the one-way membrane to prevent microorganisms from invading the pulp tissue. Additionally, it helps alleviate the high pressure in the pulp cavity caused by inflammation, thereby enhancing blood circulation within the pulp. This improvement is crucial for establishing a foundation for future vital pulp preservation treatments. A case of irreversible pulpitis caused by caries was reported, in which the dental pulp was preserved using the one-way membrane decompression. The results of a ten-month clinical follow-up indicate a positive outcome.

Imaging examinations play a crucial role in oral diagnosis. Conventional X-ray and cone beam computed tomography (CBCT) techniques are widely used in clinical practice but are associated with certain radiation risks and imaging limitations. In recent years, magnetic resonance imaging (MRI) has gained attention for its radiation-free nature and superior soft tissue imaging capabilities. This review explores the fundamental principles of MRI and its specific applications in endodontic diseases, maxillofacial surgery diseases, periodontitis, and implant restoration. Additionally, it further analyzes the technical challenges and difficulties of MRI in hard tissue imaging, aiming to provide reference and guidance for the future development of oral medical imaging.

Currently, a wide range of oral antibacterial materials are clinically used, including metal element antibacterial materials(such as silver, zinc, copper, titanium), and non-metal element antibacterial materials(such as fluorine). In recent years, cerium oxide nanoparticles have attracted great interest in the field of oral medicine due to their unique antibacterial, anti-inflammatory, antioxidant, redox capabilities. At the same time, they also have the characteristics of promoting tissue regeneration, inhibiting biofilm formation and good biocompatibility. To enhance the performance of oral materials, nanoparticles have been integrated into products such as composite resins, adhesives, and denture systems. Additionally, they have shown potential for modifying oral ceramic materials and anti-tumor effects.This review focuses on the latest research progress in various fields of oral medicine, including endodontics, periodontology, implantology, prosthodontics, and orthodontics, based on the biological characteristics of nano-cerium oxide. Our goal is to reveal the potential of cerium oxide in the diagnosis and treatment of oral diseases and to provide ideas and references for the expansion of clinical applications in oral medicine.