Resin composite, which is commonly used as a dental filling material, has some problems, such as poor wear resistance, polymerization shrinkage, and poor dentin marginal adaptability. Preheating of resin composite improves its properties. This paper reviewed the effects of resin composite preheating on its monomer conversion, marginal microleakage, mechanical properties, and irritation on dental pulp.

Objective To observe the effect of protein kinase D1 (PKD1) on the growth and metabolism of oral squamous cell carcinoma HSC-4 cells and related molecular mechanisms in the tumor microenvironment.Methods HSC-4 cell lines were transfected with shRNA plasmids. Three groups (Wild, control-shRNA, and PKD1-shRNA) were cultured under acidic or hypoxic environment for a certain time. Western blot was used to detect the expression of autophagy-related and glycolytic-related proteins. The proliferation changes were detected by CCK-8 kits.Results The PKD1-knockdown HSC-4 cell line was established. PKD1 silencing increased autophagy activity. Under hypoxic and acidic conditions, the PKD1-knockdown HSC-4 cells showed lower proliferation than the parental cells. PKD1-knockdown also decreased the expression of hypoxia induciblefactor 1α (HIF-1α) and pyruvate kinase M2 (PKM2).Conclusion Under hypoxic and acidic conditions, PKD1 gene silencing can increase apoptotic autophagy activity. Downregulated PKD1 gene expression can reduce the glycolysis of oral squamous cell carcinoma cells and inhibit tumor cell proliferation. This study revealed the important role of PKD1 in the metabolism and growth of oral squamous cell carcinoma, making it a possible target for the treatment of oral squamous cell carcinoma.

Objective This study aimed to investigate the role of protein kinase D (PKD)1 in regulating the growth, apoptosis, and drug sensitivity of the squamous carcinoma cell line SCC-25.Methods The SCC-25 cell line was transfected with either the control-shRNA or PKD1-shRNA plasmids. The stable transfected cells were selected, and the efficiency of PKD1 knockdown was detected by Western blot. The growth and apoptosis of SCC-25 were analyzed with a cell counting kit-8 (CCK8) and flow cytometry. The 50% inhibitory concentrations (IC50) of paclitaxel in the control and PKD1 knockdown cell lines were detected by CCK-8. The expression levels of Bax, Bcl-2, and P-gp were detected by Western blot.Results PKD1 was constitutively expressed and phosphorylated in various cancer cell lines. Inhibiting the expression of PKD1 in SCC-25 cells by RNA interference could inhibit the growth and promote the apoptosis of SCC-25 cells via downregulating Bcl-2 expression. Additionally, inhibiting PKD1 expression could downregulate the expression of P-gp, thereby decreasing both the IC50 and resistance index of paclitaxel.Conclusion PKD1 plays an important role in regulating the biobehavior of SCC-25. It is a potential therapeutic target for oral squamous carcinoma.

Objective To study the effect of periodontal non-surgical treatment on serum interleukin-6 (IL-6) expression and carotid vascular wall in a rat model of chronic periodontitis (CP) with type 2 diabetes mellitus (T2DM).Methods Twenty-eight 6-week-old SD rats were randomly divided into group A (control group, 7 rats) and group B (T2DM+CP group, 21 rats). According to different intervention measures, group B was randomly subdivided into B1 (natural process), B2 (periodontal mechanical treatment), and B3 (periodontal mechanical treatment + 2% minocycline hydrochloride + systemic metronidazole plus amoxicillin). Serum IL-6 was measured by enzyme-linked immunosorbent assay, and carotid tissue was observed under light microscopy after hematoxylin-eosin (HE) staining.Results The carotid artery wall of group A was normal. In group B1, the endothelial cells disappeared, the elastic fibers of the middle membrane were disordered, the local necrosis of smooth muscle tissue was amorphous particles, a small amount of calcium salt was deposited, and the wall thickening was obvious. The endothelial cells in groups B2 and B3 disappeared, and the smooth muscle cells in the middle membrane underwent denaturation. No significant thickening of the vessel wall was noted. The serum IL-6 level in group B1 continually increased with time, and it was higher than that in group A (P<0.001). The IL-6 levels of groups B2 and B3 peaked a week after the first intervention. Subsequently, IL-6 levels gradually decreased. At the last point (five weeks after the second intervention ), the IL-6 levels of groups B2 and B3 were significantly lower than that of group B1 (P<0.001).Conclusion For rats with periodontitis and diabetes, periodontal mechanical treatment may elevate serum IL-6 levels in the short term but might reduce the whole inflammatory state in the long term. Thus, this treatment might be valuable to the improvement of vascular disease. The adjunctive benefits of systemic metronidazole and amoxicillin in non-surgical periodontal therapy are decreased serum IL-6 expression and normal carotid artery.

Objective To analyze the expression and clinical significance of long non-coding RNA (lncRNA) actin filament-associated protein 1-antisense RNA1 (AFAP1-AS1) in oral squamous cell carcinoma (OSCC) and its effect on the biobehavior of OSCC cells.Methods Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of lncRNA AFAP1-AS1 in the tumor tissue and matching adjacent normal tissue of OSCC patients (n=55), SCC25 cells, and normal oral keratinocyte lines (NOK) cells. The correlation between AFAP1-AS1 expression and the clinicopathological characteristics of OSCC patients was analyzed. The relationship between AFAP1-AS1 and prognosis was also studied with the Kaplan-Meier method. AFAP1-AS1 siRNA was transfected into the SCC25 cells. Cell counting kit-8 (CCK-8) and Transwell were used to detect cell proliferation, invasion, and migration. The expression of the invasion-associated protein, AFAP1, and Rho GTPase family members, was detected by Western blot. In addition, the immunofluorescence of the cytoskeletal actin filament was observed.Results The expression of AFAP1-AS1 was higher in the OSCC tissues than in the NOK cells, and the relative expression of AFAP1-AS1 was higher in the SCC25 cells than in the NOK cells (P<0.001). AFAP1-AS1 expression was associated with the degree of differentiation, TNM stage, lymphatic metastasis, and poor prognosis of OSCC (P<0.05). Patients with a high expression of AFAP1-AS1 had lower survival rates than those with a low expression of AFAP1-AS1 (P<0.05). After transfected by AFAP1-AS1 siRNA, the expression of AFAP1-AS1 was downregulated. The inhibition of AFAP1-AS1 expression consequently suppressed the proliferation, invasion, and migration of SCC25. Moreover, AFAP1-AS1 siRNA upregulated the expression levels of AFAP1, RhoA, Rac2, Rab10, RhoGDI, and Pfn1 but downregulated the expression of RhoC. Immunofluorescence showed that AFAP1-AS1 also reduced the formation of stress filaments in the cytoskeleton and affected the integrity of the actin filament.Conclusion The expression of AFAP1-AS1 was high in the OSCC tissues and SCC25 cells and is associated with the development and prognosis of OSCC. The knockdown of AFAP1-AS1 might inhibit the proliferation and invasion of OSCC cells by regulating the integrity of the actin filament.

Objective To assess the accuracy of paralleling technique in measuring the depth of approximal infrabony pocket after periodontal flap surgery by comparing the measured and actual depths.Methods The study population included 26 patients with infrabony defects who had undergone periodontal flap surgery, bone graft surgery, and guided tissue regeneration. The measured and actual depths of approximal infrabony pocket after periodontal flap surgery were compared. The 26 infrabony defects were categorized into the following groups according to tooth position: anterior teeth, premolar, and molar groups, and according to type of infrabony pocket: one-walled, two-walled, and three-walled infrabony pocket groups. Paired t-test was used to detect the difference between the two values.Results Depth measurements of the approximal infrabony pocket depth of the anterior teeth and premolar were not significantly different (P>0.05), whereas those of the molar group were significantly different (P<0.05). In addition, depth measurements in one-walled and two-walled infrabony pocket groups showed no significant differences (P>0.05), whereas those in the three-walled infrabony pocket group were significantly different (P<0.05).Conclusion Paralleling technique can accurately measure the depth of approximal infrabony pockets of anterior teeth and premolar teeth that are one- or two-walled. However, this method cannot accurately measure the approximal infrabony pockets of molar teeth and three-walled infrabony pockets as indicated by significant differences in their depth measurements.

Objective To investigate the caries status of the first permanent molars in urban and rural children aged 10-12 in Chongqing and analyze the related factors in order to provide a theoretical basis for the prevention and treatment of children’s caries and targeted suggestions for oral health education.Methods A multi-stage, stratified, cluster, and random sampling method was used to extract 5 057 children from 18 schools in three districts and three counties in Chongqing for oral health examination and questionnaire survey from March to May 2018.Results The total caries rate of the first permanent molar was 39.2%. The decayed-missing-filled tooth was 0.84±1.20. The rate of filling teeth was 3.4%. The rate of pit and fissure sealing was 6.1%. The prevalence of the first permanent molars was significantly different between men and women, between urban and rural areas, between only children and non-only children, and between ethnic minorities and Han nationality (P<0.001). The gap between the pit and fissure sealing was significantly different between urban and rural areas (P<0.001). Multiple logistic regression analysis showed that many independent factors influence the occurrence of caries, including the frequency of brushing teeth every day, the frequency of eating desserts, the habit of eating dessert/drinking milk before going to bed, whether only-children or not, and parents’ education background, among others.Conclusion The first permanent molars of children aged 10-12 in Chongqing have a high rate of caries but low rates of pit and fissure sealing and dental caries filling. The difference between urban and rural areas is large, children’s oral health knowledge is scarce, and children have bad oral hygiene behaviors and eating habits. Children’s oral health education must be strengthened, oral health preaching must be implemented in schools, the oral health knowledge of children in school must be improved, and urban-rural differences must be minimized.

Objective This study aimed to evaluate the clinical effect of the socket-shield technique in the maxillary anterior region at one year after implant placement.Methods Ten patients with maxillary anterior teeth that cannot be reserved were enrolled. Implants were installed following the socket-shield technique and restored six months after the surgery. The thickness of the labial maxillary bone of the implant was compared before and one year after the surgery. At one year follow-up, the retention rate of the implants, Jemt classification, and pink and white aesthetic scores were evaluated. Postoperative complications and patient satisfaction were also analyzed.Results One year after installation, the retention rate of the implant was 100%. The thickness of the maxillary bone at the neck, central, and root section of the implant reduced to (0.27±0.21), (0.19±0.20), and (0.28±0.29) mm, respectively, compared with the values immediately after the operation. The thickness of the labial maxillary bone at the three measurement points immediately after and one year after the operation was statistically significant (P<0.05). No significant difference (P>0.05) of the difference thickness between immediate and one year after operation at the three measurement points. The pink esthetic scores of the implant prosthesis was 9.10±0.54, and the white esthetic scores was 9.00±0.63. No complications were observed, and the patients had a high degree of satisfaction.Conclusion The socket-shield technique could provide acceptable treatment results but cannot completely avoid the reconstruction of the labial maxillary bone of the implants. The technique exhibits favorable short-term aesthetic result, but its long-term clinical effect and aesthetic problems need to be further studied.

Objective This study investigated the feasibility and clinical result of radical resection of posterior buccal carcinoma by using the facial nasolabial fold “smile” incision approach.Methods From August 2016 to March 2017, 23 patients with posterior buccal carcinoma were included in this study and underwent radical surgery. Upon finishing the cervical lymph node dissection, an arc-shaped incision was made at 1 cm lateral to the ipsilateral angulus oris, extending along the nasolabial fold upward to the inferolateral margin of the nasal alar while downward in direct continuity with the neck dissection incision.Results Satisfactory exposure and easy resection of the primary tumor with negative surgical margin were achieved in all 23 patients. After 12-22 months of follow-up (16.5 months on average), all patients recovered favorably, and no local recurrence or distant metastasis was observed. Mouth opening was restored to normal in all cases. The scars were hidden in the nasolabial fold, thus named “smile” incision.Conclusion For posterior buccal cancer patients, the facial “smile” incision approach can satisfy the need of surgical exposure, facilitate operative performance, and preserve the annular integrity of the lips without affecting the radical tumor ablation, thereby maintaining a favorable mouth opening. With these advantages, the “smile” incision approach is considered worthy of being popularized in clinical application.

Objective To explore the prognostic factors affecting the primary surgical management of aged patients with cleft palate.Methods This study reviewed aged patients with cleft palate who received Furlow palatoplasty (surgical age≥5 years) at the cleft center at West China Hospital of Stomatology from 2009 to 2014. The study retrieved intraoperative measurements, including velar length, pharyngeal depth, cleft width, maxillary width, cleft palate index, and palatopharyngeal ratio. Speech evaluation results at follow-up at least a year after surgery were also obtained. Logistic regression and retrospective analyses were performed to identify correlative prognostic factors.Results One hundred and thirty-one patients were included (70 males and 61 females). Dichotomy logistic regression analysis revealed that pharyngeal depth was the only measurement considerably associated with postoperative velopharyngeal function. Pharyngeal depth deeper than 16 mm indicated high risk of postoperative velopharyngeal insufficiency.Conclusion Pharyngeal depth is a significant prognostic factor for the primary surgical management of aged patients with cleft palate. Pharyngoplasty might be considered when planning the primary management of aged patients.

Objective This study aimed to investigate the value of normalized iodine concentration (NIC), spectral attenuation curve slope (SACS), area under curve (AUC), and iodine concentration difference (ICD) generated from spectral CT in the assessment of parotid gland tumors.Methods Ninety-two patients with pathologically confirmed parotid gland tumors underwent arterial phase- and venous phase-enhanced CT in spectral CT. The patients were divided into the pleomorphic adenoma group (group A), Warthin tumor group (group B), basal cell tumor group (group C), and malignant tumor group (group D). The SACS, AUC, NIC, ICD were measured and analyzed. Statistical analyses were performed by one-way ANOVA, and statistical significance was set at P<0.05.Results SACS_AP, AUC_AP, and NIC_AP in group A were lower than those in other groups; SACS_VP and AUC_VP in group C were higher than those in other groups; NIC_AP and NIC_VP in group D were higher than those in other groups; and ICD in group B was a positive number. The difference in SACS_AP and AUC_AP in groups B and C, SACS_VP and AUC_VP in groups C and D, and ICD in groups A and C were not statistically significant. By contrast, the difference between the other groups was statistically significant (P<0.05). The difference in NIC_AP between groups A and B and groups C and D and the difference in NIC_VP between groups A and C, groups A and D, and groups B and C were statistically significant (P=0.005, 0.025, 0.002, 0.038, and 0.049, respectively).Conclusion Multi-quantitative parameters from spectral CT might be helpful in differentiating various types of parotid gland tumors.

Objective To investigate the influence of cuspal-coverage thickness on the stress distribution of all-ceramic onlay-restored premolars by using 3D finite element (FE) analysis and to provide references for the design of all-ceramic onlays for clinical application.Methods 3D FE models of all-ceramic onlays with three cuspal-coverage thicknesses (2, 3, and 4 mm) of endodontically treated maxillary premolar were constructed based on micro-CT images. Stress distributions in the onlay, adhesive resin cement layer, and dentin of models were analyzed under vertical load (600 N) and oblique load (200 N).Results When the cuspal-coverage thickness increased, the peak maximum principal stress value decreased inside the onlay but increased in the margin of the adhesive resin cement layer. In addition, stress concentration areas increased in the coronal residual dentin on the palatal side under oblique load.Conclusion An increase in the cuspal-coverage thickness of all-ceramic onlays may reduce the risk of rupture of the restoration but may deteriorate the restoration and cause palatal dentin fracture.

Objective This study evaluates the effects of different endodontic access methods and full-ceramic crown on the stress distribution in the maxillary central incisor by using three-dimensional finite element analysis.Methods Computed tomography scans of the maxillary central incisor were used to construct a three-dimensional finite element model of the maxillary central incisor. According to the different methods of endodontic and the prosthetic treatments, four models were established, namely, group A (traditional access cavity preparation with resin filling), group B (traditional access cavity preparation restored full-ceramic crown), group C (minimally invasive endodontics with resin filling) and group D (minimally invasive endodontics restored full-ceramic crown). A static force of 100 N and a direction of 45° was applied to the long axis of the tooth at the junction of the incisal section one-third and middle section one-third. The maximum principal stress, the von Mises stress and the modified von Mises stress of the tooth tissue were analyzed using the finite-element analysis software.Results 1) Stress peaks: the stress peaks of the maximum principal stress, the von Mises stress and the modified von Mises in group A were the largest, except that the stress peak of von Mises stress in group D was slightly lower than that in group C. The stress peaks of the maximum principal stress and the modified von Mises in group C were the lowest. The stress peaks of the maximum principal stress and the modified von Mises stress in group D were lower than those in groups A and B. 2) Stress distribution: compared with group A, the stress distribution of cervical dentin and the area of stress concentration in group C was lower and smaller. In the root dentin, the stress distribution in group C was more uniform than that in group A, and the stress was dispersed to several areas of the root apex. After crown restoration, no significant difference was observed in stress distribution between groups B and D in the root region. The stress distribution state of group B was not significantly different from that of group A. No significant difference was observed in the stress distribution state between groups D and C.Conclusion 1) From the perspective of biomechanics, the minimally invasive access was adopted for the maxillary central incisor. 2) Full crown restoration is recommended after traditional access cavity preparation. No obvious advantage is observed in stress analysis for minimally invasive endodontics-restored full-ceramic crown.

Orthodontic treatment is a time-consuming process whose duration usually takes 2-3 years. In general, long-term treatment duration possesses higher risks of complications, which may have adverse impact on patients. Therefore, exploring safe and effective adjunctive interventions to accelerate orthodontic tooth movement and shortening the treatment duration are of profound clinical significance. Currently, numerous adjunctive interventions have been generated and developed to accelerate orthodontic tooth movement, which can be divided into two main categories: surgical and non-surgical. However, an intervention that is widely accepted as a routine practice in orthodontic clinic is lacking. This article aims to review common adjunctive interventions used to accelerate orthodontic tooth movement. This review can be used as a basis to guide clinical practice, shorten treatment duration, and improve patients’ prognosis.

Inflammatory external root resorption (IERR) refers to the pathological process of dissolving the hard tissue on the outer surface of the tooth root by the body’s own immune system under the stimulation of various physical and chemical factors such as infection, stress, trauma and orthodontic treatment. Severe IERR can lead to endodontic and periodontal diseases, and even the loss of teeth. Therefore, understanding the etiology and the pathogenic mechanism of IERR are of importance in its prevention and treatment. This article will review the etiology and the regulation mechanisms of IERR.

Platelet-rich plasma and platelet-rich fibrin (PRF) are widely used in the field of stomatology. Advancements in preparation techniques and basic research have enabled the use of PRF derivatives in oral clinical applications. The evolution, preparation techniques, biological properties, and medical research progress of PRF derivatives are reviewed in this paper.

A massive variety of microorganisms live in and on the human body, especially at oral, skin, vaginal, gastrointestinal, and respiratory sites. The complicated metabolic activities of microorganisms assist human digestive function and participate in a series of physiological and pathogenetic processes. Carbohydrate-active enzymes (CAZymes) are a series of enzymes that function in degradation, modification, and formation of glycoside bonds. Microbes regulate the physiological and pathogenetic processes of human body by producing various CAZymes to degrade and modify complex carbohydrates and generate signal molecules for further utilization in human cells. Here, we reviewed the mechanisms of complex carbohydrate metabolism and related microbial CAZymes, especially in digestive tract and oral cavity. We also summarized the relationship between microbial CAZymes and human health, and proposed potential applications.

Increasing numbers of microbiome studies have enabled the development of a greater understanding of how antagonistic and synergetic microbial interactions in?uence disease outcomes. Candida albicans is an opportunistic pathogen that is commonly found in human oral micro?ora. In a healthy oral environment, Candida albicans may potentially but significantly influence the balance between the oral bacterial ecosystem and the host, leading tooral diseases. The aim of this study is to review the correlation between Candida albicans and oral pathogens and provide a deeper understanding of the nature of oral infectious diseases.

Cleidocranial dysplasia is a rare autosomal dominant hereditary disease characterized by abnormal skeletal and dental development. In this work, a case of cleidocranial dysplasia is reported, and a new frameshift mutation is confirmed by gene detection.

Maxillary defects result in esthetic and functional defects in patients. Several techniques are available for maxillary reconstruction. Herein, we present a case of maxillary reconstruction with medial femoral condyle periosteal flap by intraoral anastomosis. The characteristics of medial femoral condyle periosteal flap and the advantages of intraoral anastomosis are introduced.

Double-root mandibular third molars are the common types of mandibular third molars that are prone to impaction. Based on the summary of clinical cases and experience, the commonly used crown-root separation technique is improved as diagonal root separation technique that divides the roots by the line connecting the distal axis angle to the root furcation. This new method improves the efficiency of the operation and reduces surgical trauma. This paper details the surgical method, minimally invasive mechanics, and key points of this technique, compares the technique with the crown-root separation technique, and discusses their joint applications.