This study aims to explore the effect of inward rectifier potassium (Kir) 2.1 channel on the osteogenic differentiation of human dental follicle cells (hDFCs) and its mechanism.

hDFCs were isolated and cultured, and their source was verified by flow cytometry. Osteogenic differentiation ability of hDFCs was evaluated by osteogenic induction. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to detect the gene expression of Kir2.1 gene (KCNJ2) in hDFCs. Real-time quantitative PCR (RT-qPCR) was performed to detect the expression of the Kir2.1 gene (KCNJ2) in hDFCs before and after osteogenic induction. Patch clamp technique was conducted to record the membrane potential changes of hDFCs before and after osteogenic induction. Moreover, the effect on the osteogenic differentiation of hDFCs was confirmed by increasing the concentration of extracellular potassium ions (50 mmol·L^-1). Kir2.1 channel blockers cesium chloride (CsCl) and C19H20CINO (ML133) were applied to determine the effect of the Kir2.1 potassium channel on the osteogenic differentiation of hDFCs. At the same time, RT-qPCR was used to observe the expression changes of osteogenic differentiation related genes Runx related transcription factor 2 (Runx2) and osteocalcin (OCN) before and after the two intervention measures. Calcium imaging was performed to observe the effect of membrane potential hyperpolarization caused by decreased extracellular potassium level (2 mmol·L^-1) on intracellular calcium concentration.

RT-PCR results showed that hDFCs expressed the Kir2.1 channel gene (KCNJ2). The RT-qPCR results showed that the KCNJ2 gene expression in hDFCs was upregulated 7 days after osteogenic induction. The patch clamp results showed that the membrane potential of hDFCs hyperpolarized to (-47±5.2) mV from (-12±3.2) mV. Alizarin red and alkaline phosphatase staining results showed that increasing the concentration of the extracellular potassium or blocking the function of the Kir2.1 channel significantly inhibited the osteogenic mineralization ability of hDFCs. The membrane potential hyperpolarization increased the intracellular calcium concentration in hDFCs.

Membrane potential hyperpolarization mediated by the Kir2.1 channel plays an important role in the osteogenic differentiation of hDFCs.

This study aims to investigate the effect of X-box binding protein 1 (XBP1), a key signal molecule of ERS, on the insulin signaling pathway in adipocytes stimulated by Porphyromonas gingivalis (P. gingivalis)-lipopolysaccharide (LPS), a pathogenic bacterium of periodontitis.

Primary cultured rat adipocytes were stimulated by P. gingivalis-LPS (100 ng·mL^-1) for 4, 8, 12, and 24 h. The protein expression levels of insulin receptor substrate-1 (IRS-1), phosphoinositide dependent protein kinase (p-PDK-1), and protein kinase B (p-AKT-1) in the insulin signaling pathway were detected by Western blot analysis. pLVX-NC1, pLVX-XBP1, pLVX-NC2, and pLVX-XBP1-RNAi were transfected into adipocytes, respectively. The transfected rat adipocytes were stimulated by P. gingivalis-LPS, and the protein expression of the insulin signaling pathway was detected by Western blot.

The Western Blot showed decreased protein expression of the insulin signaling pathway in rat adipocytes stimulated with P. gingivalis-LPS compared with the control, and the difference was statistically significant (P<0.05). The protein expression levels of IRS-1, p-PDK-1, and p-AKT in the rat adipocytes of pLVX-XBP1 were significantly higher than those in pLVX-NC1 at 8 and 12 h after P. gingivalis-LPS stimulation (P<0.05). The protein expression levels of IRS-1, p-PDK-1, and p-AKT in the rat adipocytes of pLVX-XBP1-RNAi were significantly lower than those in pLVX-NC2 at 4, 8, 12, and 24 h after P. gingivalis-LPS stimulation (P<0.05).

P. gingivalis-LPS regulates the insulin signaling pathway in adipocytes th-rough XBP1.

An atomic force microscope (AFM) was used to analyze the changes in organic matter in human dentin and the effects of laser irradiation with different energy densities on the surface micro-nanostructures of human dentin.

Extracted human third molars were used in this study. Human dentin were scanned with an Er, Cr:YSGG laser (6.18, 8.04, 9.89, 11.1 J·cm^-2). The 12 samples were randomly allocated. AFM phase imaging technology and energy-dispersive spectroscopy (EDS) were applied to detect the proportional changes in the organic components on the dentine surface before and after Er,Cr:YSGG laser irradiation. AFM was capable of observing the morphological changes of the dentine surface and hydroxyapatite crystals before and after Er, Cr:YSGG laser irradiation.

After laser irradiation, the proportion of collagen with low contrast in the phase images remarkably reduced. Accordingly, the proportion of the inorganic phase significantly increased. EDS results showed that dentine was composed of Ca, P, O, and C and some trace elements of Na, Mg and Cl. After Er, Cr:YSGG laser irradiation, the C, O, and Na contents and C/Ca ratio declined significantly (P<0.05), whereas the Ca and P contents and the Ca/P ratio obviously increased (P<0.05).

Irradiating human dentine with an Er, Cr:YSGG laser at varying energy densities from 6.18 to 11.1 J·cm^-2 did not significantly influence the inorganic phase structure of the surface dentine layer. However, thermal ablation occurred in the organic component.

To construct the three-dimensional structure of the isolated teeth of patients with dentinogenesis imperfecta type Ⅱ (DGI-Ⅱ) and dentin dysplasia type Ⅰ (DD-Ⅰ) by using Micro-CT and explore internal structure and hard tissue mineralization density.

The three-dimensional structures of the third molars collected from patients with DGI-Ⅱ and DD-Ⅰ and healthy individuals of the same age were reconstructed by using Micro-CT (Mimics 17.0). The internal structures of the affected teeth along the sagittal and transverse planes were observed. The grayscale values of the enamel, crown dentin, and root dentin were calculated. Then, the mineralization densities of the different parts of the teeth of the three groups were analyzed.

The detailed three-dimensional models of the mandibular third molars with hereditary dentin defects were successfully constructed. The models contained the models of the enamel cap, dentin core, and pulp cavity. Sagittal and transverse section scans revealed that in patients with DGI-Ⅱ, the pulp cavity was incompletely calcified and the root canal was narrow, whereas in those with DD-Ⅰ, the pulp cavity and root canal were obliterated and the root of the tooth was absent. The analysis of the grayscale values showed that compared with those in the healthy group, the grayscale values of the enamel, crown dentin, and root dentin were lower in the DGI-Ⅱ and DD-Ⅰ groups (P<0.01). No significant differences in the grayscale values of the enamel and crown dentin were found between the DGI-Ⅱ and DD-Ⅰ groups (P>0.05), whereas the grayscale value of the root dentin showed statistically significant differences between the two groups (P<0.01).

The application of Micro-CT provided a simple and accurate method for the three-dimensional structure reconstruction and quantitative analysis of the mineralization density of isolated teeth with hereditary dentin defects. Although the dentin mineralization density of DGI-Ⅱ and DD-Ⅰ teeth decreased, the decrement shown by DD-Ⅰ teeth was more significant than that shown by DGI-Ⅱ teeth. The pulp cavity had abnormal calcifications, and the root canal was narrow or even occluded.

This work evaluated the effects of thickness on resin bonding strength.

We set the two bulk-fill composites Filtek Bulk Fill Posterior (FBF) and Tetric N-Ceram Bulk Fill (TBF) as the experimental groups and the two conventional composites Filtek Z100 (Z100) and Spectrum TPH (ST) as the control groups. The translucency parameter (TP), color difference, Vickers hardness (HV), and microtensile bond strength (μTBS) of dentine and the resin composites were measured at different depths.

In each group, TP and HV decreased with the increase in thickness. At the same depth, the TP of the bulk-fill composites was higher than that of the conventional composites. At the same depth, the HV of the four different resin composites followed the order of Z100>FBF>TBF>ST (except for the upper surface). Except for FBF at 3 and 4 mm, all of the other groups showed no visible color change at all the tested thicknesses. Although the μTBS values of the four different composites obtained through the bulk-fill technique were lower than those of composites obtained through the incremental fill technique, the μTBS of the bulk-fill composites obtained through the bulk-filling technique can reach 30 MPa.

Bulk-fill composites applied in single 4 mm increments can meet the requirements of clinical application. However, the color stability of some bulk-fill composites cannot be maintained.

This study aims to determine the clinical effect of an external attachment implant, called JUST J1 MINI (hereafter referred to as J1 implant), with simple tonal retention on the narrow alveolar area of the anterior teeth (4.5-5.5 mm).

A total of 27 J1 implants were implanted in 12 patients in the Fourth Affiliated Hospital of Nanchang University who were treated with narrow alveolar ridge implants. In the absence of any bone increment, all the implants were implanted with tonal retention external connection, and the survival rate of the implants was evaluated using Wheeler retention standard. The average observation period was 24 months. The amount of bone absorption at the edge of the implant, abutment abscission rate, and fracture/fracture and loosening of the implant were observed.

The marginal bone uptake of the 27 J1 implants in 12 patients was (0.069±0.032) mm 6 months after implantation and (0.142±0.079) mm 24 months after implantation. No significant difference in marginal bone uptake was observed between the implants 6 months and 24 months after implantation. No loosening of the abutment was found, and implant retention rate was 100% during the observation period.

The application of JUST J1 MINI to the narrow alveolar ridge in the anterior area can achieve a simple aesthetic effect within a short period under the condition of no bone increment.

Andrews six elements was used to explore the possible influences of gender, extraction/non-extraction, and different bracket types on the evaluation of orthodontic treatment outcome.

Digital data from 320 selected orthodontic cases in Kunming Medical University Affiliated Stomatological Hospital during the period of 2016—2020 were divided into groups in accordance with gender, tooth extraction, and type of orthodontic brackets (DamonQ self-ligating brackets and MBT brackets). Measurement was performed using Andrews six elements as standard. The mean and standard deviation of each individual score and total score for different groups were calculated and statistically tested.

The differences in total scores between female and male cases exhibited no statistical significance (P>0.05). By contrast, the scores in skeletal width change of the maxilla between extraction cases and non-extraction cases presented statistical significance (P<0.05). Moreover, the scores in the anteroposterior change in the position of the maxillary incisors, the bucco-lingual border change of the mandibular arch, and the skeletal width change of the maxilla between the DamonQ self-ligating bracket and MBT bracket cases presented statistical significance (P<0.05). The cases with DamonQ self-ligating brackets had significantly lower scores than the cases with MBT brackets in the bucco-lingual border change of the mandibular arch, the skeletal width change of the maxilla, and the anteroposterior change in position of the maxillary incisors.

Digital 3D models can be used in the clinical retrospective studies of patients after orthodontic treatment. These models can be measured repeatedly and have clinical application value. For cases with incomplete orthodontic treatment, the control of the anteroposterior position of the incisor and the width of the arch of the upper tooth is crucial. Total treatment efficiency between female and male cases exhibited no difference, but the skeletal width change of the maxilla between extraction and non-extraction cases may exert an effect on cases with complete orthodontic treatment. The group that used DamonQ self-ligating brackets may achieve good adjustment of the bucco-lingual border change of the arch.

This study aims to establish a standardized, repeatable, and simple digital evaluation method for accurately determining the effect of computer-assisted free fibula mandibular reconstruction.

A total of 20 mandibular defect cases caused by tumors were analyzed retrospectively. The coronal, sagittal, and axial mandibular angles were measured and analyzed with Mimics Research 21.0 and 3-matic Research 13.0 software before and after surgery. The effect of computer-assisted free fibula mandibular reconstruction was evaluated.

No significant difference was observed in the coronal and axial mandibular angles between the healthy and affected sides before operation (P>0.05). By contrast, a significant difference in sagittal mandibular angle (P<0.05) was noted. No significant difference was found in the coronal, sagittal, and axial mandibular angles between the healthy and affected sides after operation (P>0.05). Conversely, a significant difference was recorded in the absolute value of the coronal, sagittal, and axial mandibular angles between the healthy and affected sides pre-operation and post-operation (P<0.01). Meanwhile, a significant difference was observed in the sagittal mandibular angle between the healthy and affected sides before operation and the axial mandibular angle between the healthy and affected sides after operation in Type Ⅰ defect (P<0.05). Moreover, no significant difference in the 3D mandibular angle was found between the healthy and affected sides before and after operation in other types (P>0.05). Furthermore, no significant difference was recorded in the absolute values of the sagittal and coronal mandibular angles between the healthy and affected sides before and after operation in Type Ⅰ defect (P>0.05). Lastly, a significant difference was found in the absolute values of the 3D mandibular angles between the healthy and affected sides before and after operation in other types (P<0.05).

Computer-assisted free fibula mandibular reconstruction can significantly improve 3D mandibular deformities caused by tumors and effectively restore the accurate symmetry of the mandibular anatomical structure. The evaluation method used in this study can accurately evaluate the effects of mandibular reconstruction and provide guidance to preoperative design.

This study aims to determine factors influencing the oral health service utilization behavior of children aged 7-8 years in Weifang based on Anderson health services utilization model.

Based on the National Comprehensive Oral Disease Intervention Project, 1 826 children aged 7-8 years were selected from 10 elementary schools in four districts of Weifang City by whole-group random sampling as the study population. The modified Anderson model was used as the theoretical framework to explore the effects of situational characteristics, population characteristics, and medical behavior on children ’ s oral health service utilization.

The oral visit rate of children within 1 year was 39.8% (726 cases), of which 47.2% (342 cases) were curative visits, 20.9% (152 cases) were consultative visits, and 10.7% (78 cases) were preventive visits. Multi-factor logistic regression analysis showed that frequent parental supervision during tooth brushing, frequent parental observation of dental health, parental education level of college and above, experience of dental pain or discomfort in the last year, and poor oral health evaluated by physician were the main factors that influenced the utilization of oral health services among children (P<0.05).

The rate of preventive dental visits of children is low, and parents’ awareness of children ’ s oral health care affects the utilization rate of oral health services. Hence, parents should be taught more about children ’ s oral health care to improve the utilization of children ’ s health services.

This study aimed to assess the efficacy and safety of facial artery musculomucosal (FAMM) flap for small-medium tongue or floor of mouth defects caused by surgical resection of early-medium stage tongue or floor of mouth cancer.

A retrospective cohort study was conducted and included patients with early-medium stage tongue or floor of mouth cancer and reconstructed by FAMM flap or traditional free or axial flaps. Demographic data and surgery-related data were collected. Patients were followed up for 6 months and evaluated with satisfaction, maximal mouth opening, satisfactory contour and speech, and oral intake function at months 3 and 6.

Forty-five patients were included, with 15 in the FAMM group and 30 in the flap group. All patients finished 3 months follow-up, and 1 in each group was lost to follow-up at month 6. All followed-up patients had no recurrence or metastasis. The FAMM group had a significantly shorter surgical time than the flap group (P<0.05). The flap group had significantly more donor sites that were uncomfortable compared with the FAMM group (P<0.05). There was no statistical significance on satisfaction, but the FAMM group had better outcomes on contour, speech, and oral intake function at month 6 than the flap group (P<0.05). The FAMM group had smaller maximal mouth opening than the flap group (P<0.05) at month 3 but equivalent maximal mouth opening at month 6 (P>0.05).

FAMM flap has some advantages for small-medium tongue or floor of mouth defects caused by surgical resection of early-medium stage tongue or floor of mouth cancer, and it could be an ideal choice for clinical application.

This study aimed to compare the inhibition of anterior and posterior scars of the hard palate on maxillary growth after cleft palate surgery.

Ansys was used to establish two 3D finite element models of maxilla with complete and incomplete cleft palate. The palatal scar force with same magnitude and direction but different areas was applied in four groups in the two models. The loading force was applied to 1/4 of the anterior oral surface of the hard palate (group 1), 1/4 of the middle and anterior oral surface of the hard palate (group 2), 1/4 of the middle and posterior oral surface of the hard palate (group 3), and 1/4 of the posterior oral surface of the hard palate (group 4). The displacement of each group after loading was analyzed and compared.

In the two models, maxillary deformation occurred in all groups. The total displacement and 3D displacement comparison of each group was arranged as follows: group 1>group 2>group 3>group 4.

Scars from different parts of the hard palate after cleft palate surgery can inhibit maxillary growth in a 3D direction. The anterior scars have more serious inhibition than the posterior scars.

To screen small-molecule antibacterial drugs and investigate the antibacterial effect and mechanism of selective estrogen receptor modulators (SERMs) against Streptococcus mutans (S.mutans).

The minimum inhibitory concentration of 426 Food and Drug Administration (FDA)-approved small-molecule drugs against S. mutans was determined using the microdilution method, and the target of SERMs acting on S. mutans was explored by employing a random transposon mutant library.

Among the 426 FDA-approved SERMs, toremiphene, tamoxifen, clomiphene, and raloxifene exhibited excellent antibacterial effects against S.mutans. Results of mutant library screening showed that the two mutant strains were resistant to clomiphene. The gene sequence of the resistant strains showed that the transposon insertion sites were located in the genes of smu_546 and smu_874.

SERMs, such as toremifene, tamoxifen, clomiphene, and raloxifene, exerted obvious antibacterial effects on S. mutans, and their targets may be proteins expressed by smu_546 and smu_874 gene.

To evaluate the susceptibility of Streptococcus mutans (S. mutans) to NaF and the effects of Candida albicans (C. albicans) metabolites on the metabolic activity and drug resistance of S. mutans.

The minimum inhibitory concentration (MIC) and MIC based on metabolic activity (MIC-MA) of NaF against S. mutans were measured through the broth dilution test and D₂O-labeled single-cell Raman microspectroscopy, respectively, to explore the inhibitory effect of NaF on the growth and metabolism of S. mutans. The effects of different concentrations of C. albicans supernatant on the metabolic activity of S. mutans were evaluated by using D₂O-labeled single-cell Raman microspectroscopy. The correlation between C. albicans and S. mutans was explored throughassessing the drug resistance of S. mutans against NaF in a mixed system containing C. albicans supernatant by using D₂O-labeled single-cell Raman microspectroscopy.

The MIC and MIC-MA of NaF against S. mutans were 0.4 g·L^-1 and 1.2 g·L^-1, respectively. At the MIC level, S. mutans showed completely inhibited growth but retained high metabolic activity. Therefore, S. mutans may regain its virulence. At the MIC-MA level, the metabolic activity of S. mutans was inhibited only when the NaF concentration reached 3×MIC. At the concentration of OD₆₀₀≥0.5, the C. albicans supernatant significantly promoted the metabolic activity of S. mutans at different time points (P<0.05). In the mixed system, the susceptibility of S. mutans to NaF decreased, and statistical differences at different time points were observed (P<0.05). The metabolic activity of S. mutans was inhibited completely only at the concentration of 4×MIC (1.6 g·L^-1).

D₂O-labeled single-cell Raman microspectroscopy is suitable for evaluating the effects of drugs on bacterial metabolic activity. In the mixed system, the metabolites in the C. albicans supernatant at the concentration of OD₆₀₀≥0.5 significantly promoted the metabolic activity of S. mutans and reducedthe susceptibility of S. mutans to NaF.