The outbreak of corona virus disease (COVID-19) has raised concerns among dentists to develop strategies to prevent infection of dental equipment, materials, and patients during an epidemic period. Strategies following the National Laws and Standards of China and local standards of several provinces for controlling cross-infection and instituting protective measures for medical staff in dental clinics during an epidemic period are discussed. A proposal is put forth for dental clinics that will face similar situations in the future. Further research is warranted to address potential problems that will be encountered under such dire circumstances.

Objective This study aimed to evaluate the effects of porcine acellular cartilaginous matrix (pACM) on the proliferation and differentiation of human adipose-derived stromal cells (hADSCs). Methods pACM was prepared from porcine articular cartilage through decellularization treatment. hADSCs were isolated from human adipose tissues and cultured with different pACM concentrations. No pACM was used as the control group. The effect of pACM on hADSCs proliferation was detected by CCK-8 method. Moreover, the effect of pACM on hADSCs chondrogenic differentiation was analyzed through fluorescence quantitative polymerase chain reaction and Western blot. Results hADSCs proliferation rate in 0.5, 1.0, and2.0 mg·mL ^-1 pACM groups was not significantly different from that in the control group, whereas that in 4.0 and 8.0 mg·mL ^-1 pACM group was lower than that in the control group (P<0.05). The expression levels of pACM chondrogenic genes, including SOX-9, collagen type Ⅱ alpha 1 chain (COL2A1), and aggrecan (ACAN) and cell adhesion-related gene LAMININ in 0.5, 1.0, and 2.0 mg·mL ^-1 pACM group were higher than those of the control group (P<0.05), but that of a stemness-related gene Notch-1 was lower than that of the control group (P<0.05). No statistical difference was found in the expression of a lipogenesis-related gene peroxisome proliferator-activated receptor-γ (PPAr-γ) (P>0.05). The expression levels of chondrogenic proteins (SOX-9, COL2A1, and ACAN) were higher than those of the control group (P<0.05). Conclusion Appropriate pACM concentrations do not affect hADSCs proliferation but can induce hADSCs chondrogenic differentiation.

Objective This study aimed to investigate the distribution of Gli1 ⁺ cells in the periodontal ligament (PDL) and to evaluate their contribution in the development of periodontal tissue by using transgenic mouse lines. Methods Gli1 ^lacZ/+ mice were harvested at different ages (3, 6, and 8 weeks), and the temporal and spatial distribution patterns of Gli1 ⁺PDL cells were revealed by X-gal staining. Afterward, 3-week-old Gli1-Cre ^ERT2/+;R26R ^tdTomato/+mice were administered with tamoxifen, and the fates of Gli1 ⁺cells and their descendants were traced during periodontal development. Results A large number of Gli1 ⁺cells were detected in the PDL of the 3-week-old mice; however, their number significantly decreased from 3 weeks to 8 weeks (P<0.05). Cell lineage tracing data showed that the descendants of Gli1 ⁺ cells dramatically increased from 3 weeks to 8 weeks (P<0.05) and gradually differentiated into fibroblasts, cementocytes, and osteocytes. Conclusion The multi-differentiation potential of Gli1 ⁺PDL cells was revealed, indicating that Gli1 ⁺cells are an important cell source for periodontal development.

Objective This work aimed to determine the expression changes in LIM domain only protein 1 (LMO1) in gene transcription and protein levels during oral squamous cell carcinoma (OSCC) development. Methods The tissues in this study were taken from our team’s previous animal model building, and we performed hematoxylin-eosin (HE) staining on 49 cases. The pathological classification of the experiment group was determined on the basis of the abnormal epithelial hyperplasia degree. The expression part of LMO1 was determined by immunohistochemistry staining. The mRNA and protein LMO1 expression levels in five groups were detected by real-time fluorescent quantitative of nucleotide polymer chain reaction (RT-qPCR) and Western blot, respectively. Results HE staining determined 7 cases of the control group, 6 cases of mild epithelial dysplasia, 11 cases of moderate epithelial dysplasia, 9 cases of severe epithelial dysplasia, and 16 cases of OSCC. Immunohistochemistry results: LMO1 expression was localized in the cytoplasm, and the positive expression rates of the protein LMO1 in the control and experiment groups were 14.3% for normal buccal mucosal tissue, 33.3% for mild epithelial dysplasia, 81.8% for moderate epithelial dysplasia, 88.9% for severe epithelial dysplasia, and 93.8% for OSCC. RT-qPCR results: mRNA expression was lowest in the control group and highest in the OSCC group, the difference between the mild dysplasia and control groups was not significant (P>0.05). Pairwise comparison among other groups showed statistically significant differences (P<0.05). Western blot results: with the aggravation of the pathological degree, the protein LMO1 expression level increased gradually. The OSCC group expressed the highest LMO1 expression level. Conclusion The oral mucosa carcinogenesis models showed abnormal the mRNA and protein LMO1 expression levels, and the mRNA and protein expression levels were positively correlated with the degree of abnormal proliferation.

Objective This study aimed to observe the metastatic behavior of head and neck squamous cell carcinoma cells after knocking down heat shock protein (Hsp) 27. Methods The experiment was divided into three groups: the lentivirus vector plasmid of pLenti-shRNA-Hsp27 was transfected into UM-SCC-22B cells as experimental group (shHsp27 group), routine culture of UM-SCC-22B cells as blank control (ctrl group), UM-SCC-22B cells transfection of pLenti-shRNA-ctrl lentivirus vector as negative control (shctrl group). Through real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay to detect the mRNA expression of Hsp27 in three groups. MTS assay was performed to detect cell-proliferation changes, wounding healing assay was performed to detect cell-migration changes, and Matrigel Transwell invasion assay was performed to detect cell-invasion changes. Results The expression of Hsp27 in shHsp27 group decreased significantly; MTS assay showed that UM-SCC-22B before and after Hsp27 knockdown had similar proliferation rates after being cultured for 24 or 48 h. Compared with the ctrl group, the shHsp27 group decreased the metastatic behavior by 4.38-fold in migration and 2.03-fold in cell invasion. Conclusion Stably transfected lentivirus vector plasmid of pLenti-shRNA-Hsp27 can efficiently decrease Hsp27 expression and reduce the metastasis ability of UM-SCC-22B.

Objective To evaluate the reliability and validity of the Chinese version of the 5-item oral health impact profile (OHIP-5). Methods According to the international guidelines, the Chinese version of the OHIP-5 was produced. It was applied to patients who visit our clinic. The reliability of the scale was evaluated by internal consistency reliability and test-retest reliability. In addition, the validity of the scale was evaluated by construct validity and convergent validity. Results A total of 556 patients were enrolled in the study. The Cronbach’s alpha and the intraclass correlation coefficient values (ICC) of the Chinese version of the OHIP-5 were 0.868, 0.831, respectively. The results of the confirmatory factor analysis (CFA) showed that the one-factor model provided an acceptable fit to the data. The fit indices were: the chi-square fit statistics/degree of freedom (χ ²/df)=2.419, the goodness-of-fit index (GFI)=0.995, the adjusted goodness of fit index (AGFI)= 0.960, the normed fit index (NFI)=0.996, the incremental fit index (IFI)=0.997, the Tucker-Lewis index (TLI)= 0.985, the comparative fit index (CFI)=0.997, and the root mean square error of approximation (RMSEA)=0.070. For the convergent validity of the scale, the Spearman’s rank correlation coefficient was 0.674. Conclusion The Chinese version of OHIP-5 had a good reliability and validity by rigorous psychometric properties. Overall, it can be further promoted in clinical research and epidemiological investigations.

Objective This research aims to collect speech samples from patients with cleft palate, establish a mandarin-based database of cleft palate speech after sample analysis and classification, and provide a reference for the diagnosis of hypernasal or cleft palate, clinical education, and standard training for professional speech therapists and related research. Methods A total of 768 speech samples were collected from patients and volunteers from the Speech Therapy Center, West China Hospital of Stomatology, between May 2016 and March 2018. These samples were edited and categoried before being saved into the cleft lip and palate biologic information database. Results A mandarin-based database of cleft palate speech was established from 768 subjects, including 456 children (male 227, female 229), 312 adults (male 178, female 134), 369 normal speech voices, 155 low-level hypernasal samples, 102 moderate-level hypernasal samples, 142 high-level hypernasal samples, and 64 512 words, 24 576 phonemes, and 7 680 numbers. Conclusion This study first established a mandarin-based database of cleft palate speech, which has enormous value for the education of speech pathology of cleft palate in mandarin and further research.

Objective This work aimed to evaluate the effect of different surface treatments on the shear bond strength of resin nano ceramic to resin cement, thereby providing a theoretical basis for the improvement of clinical application. Methods A total of 150 specimens (10 mm×10 mm×3 mm) were milled from resin nano ceramic blocks (Lava Ultimate) using computer-aided design/computer aided manufacturing(CAD/CAM) technology. The specimens were randomly divided into five groups according to the surface treatment performed, as follows: control, sandblasted, sandblasted+silane, hydrofluoric acid, and hydrofluoric acid+silane groups. After the corresponding surface treatment, the specimens were cemented using Single Bond Universal Adhesive and RelyX ^TM Ultimate Clicker ^TM adhesive resin cement. All cemented specimens were placed in distilled water for 24 h and 30 days and subjected to a shear bond strength test in a universal testing machine. Results The surface treatment and water storage periods showed significant effects on bond strength. Surface treatment with sandblasted+silane showed the highest shear strength values among all tested groups, and the difference was statistically significant (P<0.05). A difference was observed between the control and hydrofluoric acid groups, and both had significantly difference compared with other groups (P<0.05). Sandblasted and hydrofluoric acid+silane groups were not statistically different, and both had significantly difference compared with other groups (P<0.05). Conclusion The surface of resin nanoceramic treated by sandblasted, sandblasted+silane, and hydrofluoric acid+silane can improve the bond strength. The sandblasted+silane group had the best the shear bond strength among the groups.

Objective This study aims to compare the efficiency of three kinds of microtube extraction devices, namely, instrument removal system (IRS), micro-retrieve and repair (MR&R) system, and MR&R system using modified microtube in removing separated instruments with different exposure lengths. Methods After a cross-section platform model was established, the IRS, MR&R, and MR&R modified microtube system with sidewall window reduced to 0.20 mm were used to retrieve various separated instrument models, and the differences in extraction effects were statistically analyzed by Chi-square test. The separated instrument models were divided into two groups: stainless steel and nickel-titanium instrument groups. In total, 23 instruments were tested for three times each. Results When the exposed length of separated instrument was 0.50 mm, the removal efficiency of the modified MR&R system group was significantly higher than those of the IRS and MR&R system groups (P<0.001). When the broken end of the fracture instrument was up to 1.00 mm, the success rates of the MR&R system and modified MR&R groups were significantly higher than that of the IRS group (P<0.01). No difference was observed among these three devices when the exposure length of separated instruments was 1.50 mm or higher. Conclusion The MR&R and modified MR&R systems have good removal effect when the exposed length of separated instrument is small.

Objective This study aimed to determine the palatal fistula rate, explore the influencing factors of Huaxi Sommerlad-Furlow (SF) palatoplasty. Methods A retrospective review of 385 consecutive cleft-palate cases was performed to determine the incidence of postoperative fistula and assess the possible contributing factors, such as sex, weight, age, cleft type, operator skills, preoperative white blood cell, preventive antibiotic use, and postoperative temperature. Results Fistulas occurred in 15/385 patients (3.9%). Among them, 1 fistula was located at the junction of the hard and soft palates, 12 fistulas in hard palate, and 2 fistulas in alveolar near the hard palate. No evidence suggested that sex, weight, age, preoperative white blood cell, preventive antibiotic use, and postoperative temperature are associated with fistula formation. The incidences of cleft palate fistulas as encountered by senior professors (3.03%) and associate senior professors (2.23%) were significantly lower than those by attending doctors (14.29%, P<0.05). The incidences of cleft palate fistulas in bilateral completely cleft palate cases (20.6%) were significantly higher than those in hard and soft (3.6%) and unilateral cleft palate cases (2.6%, P<0.05). Conclusion Huaxi SF palatoplasty can avoid the inhibited maxillary growth without requiring lateral relaxing incision, which poses an acceptable risk of fistula formation. The palatal fistula rate is not related to the sex, weight, age of operation, prophylactic use of antibiotics before operation, infection before operation, temperature after operation and other factors. The occurrence of the fistula is related mainly to cleft type and experience level of the surgeon.

Objective To study the precision of digital guide plates applied to the implant surgery of anterior teeth. Methods Fifty patients scheduled to receive implant restoration treatment in anterior teeth were enrolled in this study and divided into two groups (n=25, each group): those who were given routine implant restoration treatment (control group, 45 implants) and those who received implant restoration treatment using a digital guide plate (test group, 51 implants). After implantation, planned and placed implants were superimposed using digital software, and deviations (corona, apex, depth, degree) were analyzed. Esthetic parameters were assessed at 1 week (baseline), 6 month, and 1 year post final restoration. Pink esthetic (PES) and white esthetic (WES) scores were respectively used to evaluate the soft tissue and restoration esthetic outcome. Results The deviation parameters in the test group were significantly lower than those in the control group (P<0.05). PES and WES values recorded for the control group at 1 week, 6 month, and 1 year post final restoration were significantly lower than those in the test group (P<0.05). Conclusion The digital guide plate can improve the accuracy of the three-dimensional position of implants in the maxillary esthetic zone. As such, this device may play an important role in obtaining the ideal aesthetic effects of maxillary anterior teeth.

Objective This study aimed to explore the effects of silencing farnesyltransferase (FTase) on the migration and invasion of tongue squamous cell carcinoma (TSCC) through RNA interference. Methods TSCC cells (CAL27 and SCC-4) were cultured in vitro and then transfected with siRNA to silence FTase expression. The tested cells were categorized as follows: experimental group (three RNA interference groups), negative control group, and blank control group. mRNA expression of FTase and HRAS in each group was analyzed by quantitative real-time polymerase chain reaction. On the basis of FTase mRNA expression, the optimum interference group (highest silencing efficiency) was selected as the experimental group for further study. The protein expression of FTase, HRAS, p65, p-p65(S536), matrix metalloprotein-9 (MMP-9), hypoxia inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) was analyzed by Western blot. The invasion and migration abilities of TSCC cells were determined by Transwell invasion assay and cell wound healing assay. Results The mRNA and protein expression of FTase in the experimental group decreased compared with that in the negative control and blank control groups (P<0.05). The mRNA and protein expression of HRAS was not significantly different among the groups (P>0.05). In the experimental group, the protein expression of p-p65(S536), MMP-9, HIF-1α, and VEGF decreased (P<0.05), whereas that of p65 had no significant change (P>0.05). The migration and invasion abilities of the experimental group were inhibited significantly (P<0.05). Conclusion Silencing FTase in vitro could effectively downregulate its expression in TSCC cell lines and reduce the migration and invasion abilities to a certain extent. FTase could be a new gene therapy target of TSCC, and this research provided a new idea for the clinical treatment of TSCC.

Objective This study aimed to explore the target relationship between miR-204-5p and bromodomain-containing protein (BRD) 4, as well as their effects on cell proliferation, migration, and invasion in tongue squamous cell carcinoma SCC25. Methods Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to detect miR-204-5p and BRD4 expression levels in tongue squamous cell carcinoma and different cell lines. TargetScan and dual luciferase reporter assay were used to confirm the target relationship between miR-204-5p and BRD4. The effects of miR-204-5p on SCC25 cell proliferation were examined by cell counting kit (CCK) 8 assay, whereas those on SCC25 cell migration and invasion were determined by Transwell assay. RT-qPCR and Western blot were used to detect the effects of miR-204-5p mimics and inhibitors on BRD4 expression. Transwell and CCK8 assays were used to detect the effects of miR-204-5p on proliferation, migration, and invasion through BRD4 regulation. Results miR-204-5p was significantly downregulated in the tissues and cells of squamous cell carcinoma, and BRD4 showed the opposite result. The increase in miR-204-5p expression can inhibit the proliferation, migration, and invasion of SCC25 cells. TargetScan and luciferase test confirmed that miR-204-5p and BRD4 had a negative regulatory relationship with BRD4, respectively. Moreover, miR-204-5p mimics can inhibit BRD4 expression, and miR-204-5p inhibitors can promote BRD4 expression upregulation. When miR-204-5p and BRD4 were overexpressed in SCC25 cells, BRD4 can make up for the inhibitory effect of miR-204-5p on SCC25 cells. Conclusion miR-204-5p could inhibit proliferation, migration and invasion in tongue squamous cell carcinoma SCC25 cells by targeting BRD4 gene.

Exosomes are 40-100 nm vesicles that are released into the extracellular environment upon the fusion of multivesicular bodies with the plasma membrane. The biologically cargoes transported by exosomes are diverse. Exosomes are important carriers of signal transmission and interaction between cells. Exosomes are believed to play an important role in tissue repair and bone regeneration. Studies have evaluated that exosomes secreted by cells play an increasingly significant roles in bone tissue engineering and have multiple functions, including regulating immunity, promoting cell proliferation and differentiation, enhancing bone regeneration and angiogenesis. The review analyzes the characteristics and biological properties of different cell-derived exosomes in the bone environment, summarizes their research progress in bone repair, and discusses the challenges and future directions for their application in bone tissue engineering.

Precancerous lesions of oral mucous membrane diseases and oral cancer are common diseases in developing countries, especially in South Asia. However, the cancerous mechanism remains unclear, and no efficient treatment and prognosis measure are currently available. Thus, precancerous lesions of the oral mucosa and oral cancer animal models must be identified to further understand their function. In this paper, we systematically review the development of oral mucosal precancerous lesions and oral cancer animal models by referring to related research.

Primary tooth root canal therapy is a treatment performed on primary teeth diagnosed with pulpitis or periapical periodontitis. This procedure requires perfect instrumentation, disinfection, and filling of root canals to eliminate infection, control inflammation, relieve pain, prevent pathological effects on inherited permanent tooth, and prolong primary tooth preservation. This paper reviews the research history on primary tooth root canal treatment and summarizes the progress on primary tooth root canal treatment, including anatomical morphology, root canal preparation, root canal disinfection, root canal filling, and application of antibiotics.

Implant osseointegration is an important biological basis for dental implantology. Many factors, including surgical factors, implant factors, and patients’ own factors, affect implant osseointegration. Notably, the application of systemic drugs to improve implant osseointegration has become a research hotspot. This article reviews the effects of systemic drugs on implant osseointegration based on animal researches to provide systemic drug selection to improve implant osseointegration and lay a good foundation for later clinical trials.

Erythropoietin-producing hepatomocellular receptors and their receptor-interacting proteins (Eph/ephrin) can participate in the regulation of growth and development and promote the development of diseases through short-distance signal transduction between cells. To study the mechanism of Eph/ephrin and oral-related diseases, we provided a new theoretical basis and a strategy for the treatment of oral diseases. The Eph/ephrin pathway has been used to regulate oral diseases, especially in periodontal disease prevention, orthodontic bone reconstruction, and biological treatment of oral tumors. This paper reviews the research progress of Eph/ephrin pathway in oral-related diseases.

Langerhans cell histiocytosis is commonly found in cranial bones and rarely found in the mandible. This article presents a case of mandibular Langerhans cell histiocytosis and discusses its pathogeny, clinical features, diagnosis, and treatment.

Branching morphology is important to ensure that the organ can obtain the efficient functional morphology in a limited volume. The submandibular gland is a crucial model for studying the morphological processes of organ branches. Harvesting the submandibular gland from mouse embryo is also an essential research technique. In this paper, a modified method for obtaining the submandibular glands of mouse embryo was introduced, and the whole process of obtaining and establishing in vitro organ culture was briefly introduced to accurately simulate branch morphogenesis for vivo development and related research.