Objective To investigate the mechanism by which serum amyloid P component (SAP) alleviates periodontitis in mice, providing an experimental basis to establish SAP as a novel therapeutic agent for periodontitis. Methods Ethical approval was obtained from the Institutional Animal Ethics Committee. Periodontitis models were established in wild-type (WT) mice and SAP-transgenic (SAP-Tg) mice, divided into four groups: WT control (WT group), WT periodontitis (WT+P group), SAP-Tg control (Tg group), and SAP-Tg periodontitis (Tg+P group). On day 7, the mice were euthanized, and periodontal tissues, teeth, and alveolar bone were collected. SAP protein expression was detected by enzyme-linked immunosorbent assay (ELISA). Micro-CT and HE staining were used to measure alveolar bone resorption (distance from the cementoenamel junction to the alveolar bone crest). Tartrate-resistant acid phosphatase (TRAP) staining was performed to assess osteoclast number, and immunohistochemistry (IHC) was employed to evaluate macrophage infiltration. The expression levels of inflammatory cytokines including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were measured by qRT-PCR. Oral microorganism composition was analyzed using 16S ribosomal RNA (16S rRNA) gene sequencing. Additionally, macrophages from WT and SAP-Tg mice were isolated to establish an in vitro inflammation model, divided into WT+LPS and Tg+LPS groups. The expression of macrophage polarization-related genes including inducible nitric oxide synthase (iNOS), CD86, CD163, and CD206) were assessed by qRT-PCR. After the induction of osteoclast differentiation, TRAP staining was performed. Results ELISA results demonstrated that periodontal tissues from Tg+P group mice exhibited higher levels of SAP expression compared to the WT+P group. Micro-CT and HE staining analyses revealed that the Tg+P group showed reduced alveolar bone resorption, indicated by a shorter distance between the cementoenamel junction and alveolar bone crest, compared to the WT+P group. Furthermore, TRAP staining results indicated a decrease in osteoclast numbers in the Tg+P group compared to the WT+P group. IHC and qRT-PCR results indicated reduced macrophage infiltration and decreased expression of IL-1β, IL-6, and TNF-α in the Tg+P group. Oral microorganism sequencing showed no significant difference in periodontitis-associated pathogenic bacteria between WT+P and Tg+P groups. In vitro experiments demonstrated that compared to the WT+LPS group, the Tg+LPS group exhibited downregulated M1 macrophage markers (iNOS and CD86) and upregulated M2 macrophage markers (CD163 and CD206). TRAP staining confirmed fewer osteoclasts in the Tg+LPS group. Conclusion SAP overexpression effectively alleviates periodontitis severity in mice by inhibiting M1 macrophage polarization, reducing pro-inflammatory cytokine expression, and suppressing osteoclast differentiation, thereby attenuating alveolar bone resorption.

Objective To explore intraoral scanning strategies for elastic impressions during the fabrication process of duplicate complete dentures and to investigate the accuracy of 3D scanning strategies on the surface of complete dentures. The goal is to utilize digital technology to improve the traditional fabrication methods of duplicate complete dentures. Methods Eight sets of replicated denture model for edentulous patients were selected. Conventional complete dentures were created based on these models. The condition of the patient’s alveolar bone atrophy was simulated on these models, and elastic impressions were built using complete dentures as individual trays with polyether silicone rubber materials. TRIOS 3 intraoral scanners were used to scan the elastic impressions according to four scanning strategies (A: tissue surface - artificial teeth - polished surface of denture; B: artificial teeth - polished surface of denture - tissue surface; C: tissue surface - artificial teeth - polished surface of denture in powder spraying state; D: artificial teeth - polished surface - tissue surface in powder spraying state). The 3D data obtained by the desktop scanner were used as the reference. The maximum deviation, average deviation, and standard deviation of the 3D data models obtained by different scanning strategies were compared using the Geomagic Control X software. For the complete denture, the maximum deviation was 0.3 mm. The obtained results were analyzed by PASW Statistics 18 software. Results The maximum deviation value of the maxillary scans in the 3D data compared with the desktop scanning data was (0.188 ± 0.109) mm, and that of the mandibular scans was (0.200 ± 0.099) mm. There was no statistically significant difference between them (t = 0.139, P = 0.624). However, the maximum deviation values of both the maxillary and mandibular scans were lower than the required maximum error (0.3 mm) for complete dentures in clinical practice, and the difference was statistically significant (P<0.001). The average deviations of the maxillary and mandibular models were (0.024 ± 0.212) mm and (0.014 ± 0.014) mm, respectively, and the differences were statistically significant (t = 4.228, P = 0.021). The standard deviations of the maxillary and mandibular models were (0.074 ± 0.032) mm and (0.074 ± 0.034) mm, respectively. There was no statistically significant difference between them (t = 0.813, P = 0.371). There were no statistically significant differences in the average deviations and standard deviations of each scanning strategy between the maxillary and mandibular impressions within and between groups. Comparing the deviation between the tissue surface and the polished surface of the 3D data of the upper and lower jaws on the oral scanner and the desktop scanner shows that the areas with larger deviations in the maxillary impressions were mainly concentrated in the maxillary tuberosity and palatal vault regions, and those in the mandibular impressions were mainly concentrated in the molar posterior pad region. Conclusion The digital impressions formed by intraoral scanning the maxillary and mandibular elastic impressions can meet the requirements for clinical fabrication of complete dentures. However, in clinical practice, special attention should be paid to checking and adjusting the fit of the maxillary tuberosity and palatal vault and the mandibular molar posterior pad areas of the complete dentures.

Objective This study compares the effects of lithium disilicate glass ceramic onlays and full crowns in restoring cracked teeth that have undergone root canal therapy, providing a reference for the restoration method of cracked teeth that have undergone root canal therapy. Methods This study was approved by the hospital’s medical ethics committee, and all patients signed the informed consent form. Patients with cracked teeth who underwent root canal treatment in our hospital from January 2022 to January 2023 were enrolled in this study. According to the inclusion and exclusion criteria, 60 patients were screened and enrolled, with a total of 60 affected teeth. The patients were divided into the onlay group and full crown group at a ratio of 2:3 using the random number table method. Lithium disilicate glass ceramic onlays were used to restore the affected teeth in the onlay group (24 cases), and lithium disilicate glass ceramic full crowns were used to restore the affected teeth in the full crown group (36 cases). At 3, 6, and 12 months after the repair, the restoration effect was evaluated and compared with the modified USPH Standard (the aesthetic, functional, and biological aspects of restorations). According to the biological definition of survival, survival analysis was conducted on the affected teeth in both groups. Results At 3, 6, and 12 months after the repair, 85% of cases in the onlay group achieved grade A, while 80% of cases in the full crown group achieved grade A. There was no statistically significant difference in the restoration effects between the onlay group and the full crown group (P > 0.05). The 12-month survival rate of cracked teeth in the onlay group reached 95.65%, and the 12-month survival rate of cracked teeth in the full crown group reached 94.12%. There was no statistically significant difference in the retention of the affected teeth (P > 0.05). There was no significant effect of age, gender, tooth position, dentition, direction of cracks, the number of marginal ridges associated with cracks, or the type of restoration on the survival status of cracked teeth. (P > 0.05). Conclusion For cracked teeth that have undergone root canal therapy, the short-term effect of lithium disilicate glass ceramic onlays is comparable to that of full crowns, and both have good short-term effects. Onlays are less invasive and are expected to become an alternative restoration method to full crowns.

Objective To investigate the accuracy of the mandibular curve of Spee and mandibular curve of Wilson curve, mandibular posterior crown inclination, maxillary and mandibular arch width, and mandibular incisor labial inclination changes in the invisible orthodontic treatment of extracted and non-extracted patients to provide a basis for the study of the therapeutic efficacy of the invisible aligner. Methods This study was approved by the Unit Medical Ethics Committee. Adult bony Class I patients treated with invisible aligners between 2016 and 2023 were selected and categorized into 32 cases in a group with four first premolar extractions and 33 cases in a non-extraction group. The initial scanning model (T1), the orthodontic plan design model (T2), and the scanning model after alignment and leveling (T3) were collected, and the scanning data at different time points were exported to STL format files. They were then analyzed and measured using GOM Inspect 2019 software; the clinical effect (T1-T3) was defined as AC, and the expected result (T1-T2) was defined as CC. To explore the mandibular curve of Spee, the leveling accuracy of the mandibular Wilson curve (AC/CC×100%), the change in mandibular posterior crown inclination, the change in maxillary and mandibular arch width and the change in mandibular incisor labial inclination. The results were tallied using R4.3.2 software. Results The leveling accuracy of the mandibular curve of Spee was 3.2% and 10.1% in the extraction and non-extraction groups, respectively; the leveling accuracy of the mandibular first molar in the extraction and non-extraction groups was 9.5% and 4.2%, respectively, and the leveling accuracy of the mandibular second premolar was 32.8% and 25%, respectively. The leveling accuracy of the mandibular curve of Wilson was 126% in the extraction group compared to 704% in the non-extraction group. The maximum values of AC for crown inclination of the mandibular posterior teeth were all found in the first molar and the minimum values in the second premolar (P< 0.05); CC was the greatest in the second premolar and the least in the first molar in the extraction group (P< 0.05), and in the second molar and the least in the second premolar in the non-extraction group (P< 0.05). There was no significant difference in the change of maxillary and mandibular arch widths in the extraction group (P> 0.05); the AC of the arch widths at the maxillary first molar and at the mandibular second premolar and first molar in the non-extraction group was significantly greater than the CC (P< 0.05). The AC of the mandibular second premolar crown inclination was significantly greater in the non-extraction group than in the extraction group (P < 0.05), showing a more pronounced buccal inclination of the crowns; in contrast, there was no significant difference between the mandibular molar crown inclination AC and CC in the two groups (P > 0.05). The CC of mandibular curve of Spee in the extraction group was significantly greater than that in the non-extraction group (P < 0.05), whereas there was no significant difference in AC between the two groups (P > 0.05). In addition, the AC of the labial inclination of the mandibular incisors in the extraction group and the non-extraction group was smaller than the CC, but both were positive, indicating an increase in the degree of labial inclination of the mandibular incisors. Conclusion The invisible aligner mandibular curve of Spee leveling was poorly expressed, and there was a tendency for overexpression of the mandibular curve of Wilson leveling. Increased labial inclination of the mandibular incisors was observed in patients. The extraction group was accurately predicted in arch width control, there was overexpansion in the non-extraction group.

Objective To explore the clinical characteristics, diagnosis, and treatment of ectopic thyroid gland in the parotid gland area, and to provide clinical ideas for the diagnosis and treatment of ectopic thyroid gland. Methods A case of a normal thyroid gland with ectopic thyroid gland tissue in the parotid gland area in the neck was reported. The male patient was 20 years old. The chief complaint was the discovery of a painless mass gradually increasing under the left earlobe for one month. Clinical examination showed obvious bulging of the tissue under the left earlobe. A strip-shaped mass approximately 3.0 cm long could be palpated. It was soft in texture, with a clear boundary, and located under the skin. The skin was pale red and of normal temperature. The body position movement test was negative. Color Doppler ultrasound of the thyroid gland in the neck showed that the shape and size of the thyroid gland were normal. CT images of the head and neck showed a band-like soft tissue density shadow at the area of the parotid gland behind and below the left earlobe, with a clear boundary. The CT value was approximately 30 HU, and further enhancement yielded no additional findings. The admitting diagnosis was a mass in the left parotid gland area. The tumor was incised using a conventional surgical method for the parotid gland area. During the operation, it was found that the tumor was located under the skin, and the contents were bright-red granulomatous tissue without a capsule and adhesive to the skin tissue. The parotid gland capsule was not involved. After the tumor was completely scraped off, intermittent suturing was performed. The resected tumor was sent for pathological examination. A retrospective analysis of the diagnosis and treatment of this type of case was conducted in combination with a literature review. Results The wound of the patient failed to heal in the first stage after the operation. By applying iodoform gauze for pressurized dressing changed weekly, the wound gradually healed about 2 months later. The postoperative pathological report showed an ectopic thyroid gland in the left parotid gland area. The results of the literature review indicate that ectopic thyroid glands can be partial or complete. In the former, normal thyroid gland tissue exists in the neck, and some thyroid gland tissue appears in other locations, mostly at the base of the tongue and mediastinum. In the latter, the thyroid gland in the neck is absent. Both can present with abnormal thyroid gland function and local compression symptoms, and the symptoms are more obvious in patients with a complete ectopic thyroid gland. Ectopic thyroid glands are mainly diagnosed and differentiated through physical examination and imaging examination. Ectopic thyroid glands occurring subcutaneously in the parotid gland area are extremely rare. Physicians should design personalized treatment plans based on clinical examinations and surgical indications. Conclusion A subcutaneous ectopic thyroid gland in the parotid gland area is rare. For ectopic thyroid gland surgery, a reasonable surgical plan should be designed considering the patient's aesthetic needs and prognosis. Puncture biopsy should be performed when necessary to formulate the surgical plan.

Objective To investigate treatment strategies for chronic periapical periodontitis in prematurely erupted premolars and provide guidance for managing pulp and periapical diseases in young permanent teeth with immature roots. Methods A regenerative endodontic procedure (REP) was performed on a prematurely erupted maxillary left first premolar (tooth 24) at Nolla stage Ⅶ with chronic apical periodontitis, following standardized protocols including root canal irrigation, disinfection, and coronal sealing. The case was followed up, and a literature review was conducted. Results Clinical resolution of symptoms was observed on tooth 24, with sustained root development. After a 20-month follow-up, the tooth had restored biological function. Literature synthesis revealed that periapical infections in prematurely erupted permanent teeth predominently arise from pulp exposure and bacterial infection, with retrograde infection being rare. For young permanent teeth with necrotic pulp, regenerative endodontic procedures has been established as the treatment of choice to promote apical closure and root maturation. The critical steps of regenerative endodontic procedures include thorough disinfection, induced bleeding to form a fibrin scaffold, and coronal sealing to facilitate stem cell recruitment and differentiation. Conclusion Regenerative endodontic procedures represents an effective and viable treatment option for prematurely erupted young permanent teeth with chronic periapical periodontitis.

Periodontal homeostasis is regulated by the complex interplay between the gingival epithelial barrier, the extracellular matrix of soft tissues, the bone coupling system, and immune responses within the periodontal region. Gingival epithelial cells are primarily composed of keratinocytes and a small proportion of non-keratinocytes, and they are integral to the formation of the gingival epithelial barrier. This epithelial barrier plays a fundamental role in defending against pathogens, exogenous substances, and mechanical stress. This study aims to explore the intrinsic connections between gingival epithelial cells and periodontal homeostasis. Research has shown that gingival epithelial cells participate in maintaining periodontal homeostasis through multiple pathways: ① gingival epithelial cells respond to the inflammatory environment by undergoing proliferation, migration, epithelial-mesenchymal transition, and forming apoptosis-mediated neutrophil extracellular traps; ② when gingival inflammation damages the epithelial barrier, lipopolysaccharides cannot be easily removed, and gingival epithelial cells play a defensive role by activating innate immune responses; ③ the interactions of gingival epithelial cells with oral microbiota and immune cells are essential for maintaining periodontal homeostasis. Thus, gingival epithelial cells are closely associated with periodontal homeostasis. However, the crucial role and mechanisms of gingival epithelial cells in the maintenance of periodontal homeostasis are not clear, which provides novel insights for the research of periodontal homeostatic medicine.

Endodontic microsurgery is an important treatment for endodontic disease and maxillary sinusitis of endodontic origin of maxillary posterior teeth. However, endodontic microsurgery is challenging due to the close proximity between the maxillary posterior teeth and the maxillary sinus, which may lead to complications of mucosal perforation of the maxillary sinus floor. Endodontic microsurgery combined with maxillary sinus floor elevation is considered as a solution, namely natural tooth-related maxillary sinus floor elevation. The evaluation and design of natural tooth-related maxillary sinus floor elevation are closely related to local anatomic relationships. This article provides a systematic review of the anatomical considerations of endodontic microsurgery, namely natural tooth-related maxillary sinus floor elevation in the maxillary posterior region in terms of maxillary posterior teeth, alveolar ridge of the maxillary posterior region, and maxillary sinus. The literature review showed that a minimum of 3 mm of the root apex must be removed during endodontic microsurgery to eliminate the majority of apical ramification, lateral canals, and severe root curvatures. The height and thickness of alveolar ridge bone are important indicators for evaluating and designing endodontic microsurgery for maxillary posterior teeth. Maxillary sinus floor mucosa, maxillary sinus ostium, the proximity between maxillary posterior teeth and the maxillary sinus floor, maxillary sinus septa, posterior superior alveolar artery, and greater palatine artery, and possible maxillary sinus cysts are the main maxillary sinus-related considerations. When the maxillary sinus floor is below the line between the buccal and palatal roots, when the root apices contact or protrude into the maxillary sinus floor, or when the apical lesion is directly connected to the maxillary sinus mucosa, natural tooth-related maxillary sinus floor elevation is applicable. Anatomical considerations should be emphasized throughout endodontic microsurgery and natural tooth-related maxillary sinus floor elevation in the maxillary posterior region. Further studies are required to investigate the clinical design and difficulty assessment of natural tooth-related maxillary sinus floor elevation in different local anatomical relationships.

Healthy dental pulp is essential for preserving teeth and maintaining their normal function. Vital pulp therapy (VPT) is widely used in clinical applications because it aims to preserve vital pulp and enhance the long-term survival of teeth. An accurate diagnosis of pulp vitality is a prerequisite for successful VPT. However, accurately assessing pulp viability remains challenging in clinical practice. Pulp viability is influenced by various factors, including the type of pulp exposure, caries status, periodontitis, trauma, treatment factors, patient age, and individual differences. Assessing pulp viability requires a comprehensive consideration of medical history and clinical manifestations, along with a combination of various auxiliary methods, such as pulp sensibility tests, pulp blood flow tests, imaging techniques and molecular diagnostics. In the future, the technology for assessing pulp vitality should evolve toward chairside, visualization, and precision techniques, to achieve consistency between clinical and histological diagnoses, thereby providing patients with the most effective treatment.

The efficacy of root canal therapy, as a core intervention for endodontic and periapical diseases, is highly dependent on the effectiveness of antimicrobial drugs. Although traditional drugs such as calcium hydroxide, chlorhexidine, and antibiotic pastes commonly used in the clinic play a role in preventing and controlling infections, they have obvious limitations. These drugs influence the mechanical properties of dentin, insufficiently solubilize necrotic tissues, and are susceptible to bacterial resistance, which makes achieving the desired effectiveness and safety difficult. Traditional macromolecular root canal drugs also face the challenge of the complexity of the root canal system. With the rapid development of material science in recent years, new antimicrobial agents have emerged. Metallic nanomaterials such as silver nanoparticles and zinc oxide nanoparticles are widely used in the medical field due to their unique physicochemical properties and superior antimicrobial properties. Chitosan nanoparticles have superior biosafety, calcium hydroxide nanoparticles compensate for the limitations of traditional calcium hydroxide formulations, and quaternary ammonium polyethyleneimine nanoparticles can confer antimicrobial properties to existing oral materials. Novel antimicrobial nanoparticles using nano-delivery systems, such as mesoporous calcium silicate and mesoporous silica, carry antimicrobial molecules with significant advantages in terms of anti-biofilm, biosafety, and promotion of tissue repair. Further, these agents reduce drug resistance, which improves prospects for application compared to traditional root canal disinfection drugs. The breakthrough of nanotechnology provides a novel direction for the innovation of root canal treatment drugs. Therefore, this paper reviews the research progress of nano-antimicrobial materials in root canal therapy.

Oral squamous cell carcinoma (OSCC) is a malignant tumor that seriously threatens human health. Its typical biological characteristics include strong local invasiveness, high lymph node metastasis rate, and high recurrence rate after treatment. Hepatocyte growth factor (HGF), cellular-mesenchymal to epithelial transition factor (c-Met), and the HGF/c-Met signaling pathway are involved in the regulation of the occurrence and development of OSCC. HGF and c-Met proteins are overexpressed in OSCC, and multiple studies have suggested that they are significantly associated with the malignant characteristics of tumors and poor prognosis. Furthermore, the abnormal activation of the HGF/c-Met signaling pathway (driven by HGF-dependent autocrine/paracrine or non-dependent mechanisms such as MET gene mutations, amplification, fusion, and protein overexpression) can synergistically promote tumor cell invasion, metastasis, and angiogenesis by activating downstream signaling pathways. However, HGF/c-Met can also mediate immune escape by promoting lactate secretion increase, inducing programmed death ligand 1 (PD-L1) expression upregulation, activating and expanding myeloid-derived suppressor cells, and promoting the proliferation of regulatory T cells (Tregs). In addition, the crosstalk between the HGF/c-Met signaling pathway and key pathways such as phosphatidylinositide 3-kinases (PI3K)/protein kinase B (AKT), epidermal growth factor receptor (EGFR), Janus kinase (JAK)/signal transducer and activator of transcription (STAT3), and non-coding RNAs can also promote tumor progression. Currently, three types of targeted drugs have been developed targeting the HGF/c-Met pathway: HGF monoclonal antibody, c-Met monoclonal antibody, and tyrosine kinase inhibitors. Some of these drugs have entered clinical trials. However, the emergence of drug resistance during treatment, especially the bidirectional compensatory activation of alternative signaling pathways such as EGFR, has become a major challenge in clinical practice. This article aims to provide an in-depth analysis of the mechanism of action of the HGF/c-Met pathway in OSCC and its interaction with other pathways, and to review the current research status of existing therapeutic drugs. The aim is to provide an important theoretical basis for developing more effective combined treatment strategies and achieving individualized precise treatment, ultimately improving the clinical prognosis and quality of life of patients.