With the comprehensive application and development of implant dentistry in recent years, multi-institutional data have supported a large number of clinical research findings. A consensus was gradually reached on the evaluation of the state and effect of implants and types of indicators that were selected after restoration. This study aims to examine the fre-quently used criteria to define treatment success in implant dentistry.

Dental implants represent the majority of treatment strategies used to replace missing teeth. However, peri-implant diseases caused by disturbance in peri-implant microbiological balance are among the reasons for implant failure. Since the 1980s, peri-implant microorganisms have been a hot research topic in dental microbiology. The bacterial ecology between the disease and health largely differs, which directly or indirectly increases the risk of peri-implant diseases. Accordingly, the determination of the ‘core microbiome’ of peri-implantitis and peri-implant mucositis is a key point of recent research.

Objective To investigate the effect of sex determining region Y-box 9 (SOX9) on epithelial mesenchymal transition (EMT) and cloning of oral squamous cell carcinoma (OSCC). Methods siRNA control, SOX9 siRNA were trans-fected into BcaCD885 cells in OSCC. Simultaneously, cells that did not undergo transfection were used as the control. Quanti-tative real time polymerase chain reaction (qRT-PCR) and Western blot were used to select SOX9 siRNA1 with enhanced interference effect. A cell cloning assay was used to determine the cell’s clone formation ability. E-cadherin and Vimentin expressions were detected by immunofluorescence. The expressions of E-cadherin, matrix metalloprotease 2 (MMP-2), Vi-mentin and matrix metalloprotease 9 (MMP-9) were detected by Western blot. Cell invasion and migration were detected in the Transwell compartment. Results The levels of SOX9 mRNA and protein in SOX9 siRNA cells were significantly lower than those of the control (P<0.05). An increase in the number of SOX9 siRNA1 cell clonesled to the considerable decrease of the number of cell invasion and migration. In addition, levels of MMP-2 and MMP-9 proteins in cells decreased significantly compared with the control (P<0.05). The level of Vimentin expression in SOX9 siRNA1 cells decreased, and expression level of E-cadherin was elevated. Cell EMT was inhibited com-pared with the control, and the difference was statistically significant (P<0.05). Conclusion Down-regulation of SOX9 inhibited EMT, clonogenic formation, cell invasion and OSCC migration.

Objective This study aimed to investigate the expression patterns and relationship of microtubule-associated protein 1 light chain 3 (LC3B) and mammalian target of rapamycin (mTOR) in oral leukoplakia (OLK) in smokers and never-smokers. This work also analyzed the relationship between smoking and the carcinogenic potential of OLK. Methods Immu-nohistochemistry was used to detect the expression of LC3B and mTOR in 120 patients with OLK. Clinical data from 120 smokers and never-smokers with OLK were analyzed. Subsequently, the relationships among LC3B and mTOR expression, clinical factors, and smoking were analyzed. Results Smoking and nonsmoking patients with OLK differed in terms of gender, age, lesion location, pathological typing, and carcinogenic situation. The positive rate of LC3B in never-smokers was higher than that in smokers. Whereas the positive rate of mTOR in smokers was higher than that in the corresponding never-smokers, and the differences were statistically significant (P<0.05). Smoking was positively correlated with the positive rate of mTOR (P<0.05), and had no significant correlation with LC3B expression. The positive rates of LC3B and mTOR were negatively correlated with the intensity of smoking (P<0.05). Conclusion The effect of smoking habits on OLK may be linked to the expression of proteins that are directly associated with autophagy.

Objective This study aims to establish an effective and stable periodontal ligament cell line stably expressing human telomerase reverse transcriptase (hTERT) gene by using the adenovirus method. Methods Polymerase chain reaction (PCR) was used to amplify the full length of hTERT gene to construct recombinant adenovirus plasmid pAd-pshuttle-cmv-hTERT. Packaged adenovirus particles were used for infection of human periodontal ligament cells. The expression levels of hTERT and osteogenic genes, such as alkaline phosphatase, Runt-related transcription factor 2, bone sialoprotein, osteocalcin, osteopontin, and collagen Ⅰ mRNA, were detected by quantitative real-time PCR (qRT-PCR). The ability of osteogenic differentiation was observed by alizarin red staining, and the cell proliferation was determined by CCK-8. Results Adenovirus particles containing the hTERT gene were successfully constructed and infected with periodontal ligament cells. The infected cells were similar to normal periodontal ligament cells. The qRT-PCR results showed that hTERT and osteogenesis-associated genes were highly expressed in the periodontal ligament cell lines constructed by adenoviruses. Alizarin red staining showed that the periodontal ligament cell line had strong osteogenic differentiation capability. CCK-8 showed that the periodontal ligament cell line had strong proliferation capability. Conclusion The human periodontal ligament cell line with high effi-ciency and stable expression of hTERT was established by the adenovirus method, thereby providing an ideal cell line for studying the mechanism of periodontal regeneration.

Objective This study aimed to investigate the gene mutational characteristics of cathepsin C (CTSC) gene in a Chinese patient with Papillon-Lefèvre syndrome (PLS) and further confirm the genetic basis for the phenotype of PLS. Methods Peripheral blood samples were obtained from the PLS proband and his family members (his parents and younger brother) for genomic DNA extraction. The coding region and exon boundaries of the CTSC gene were amplified and sequenced by polymerase chain reaction and direct sequencing of DNA. Results Compound heterozygous mutations of CTSC gene were identified in the patient. A heterozygous missense mutation occurred in the 800th base of exon 6, and the base T in the base pair was replaced by C (c.800T>C). The encoded amino acid leucine changed to proline (p. L267P). A heterozygous missense mutation occurred in the 1015th base of exon 7, and base C in the base pair was replaced by T (c.1015C>T). The encoded amino acid arginine changed to cysteine (p.R339C). Among the mutations, c.800T>C originated from the mother, c.1015C>T was identified from the father. No mutations were detected in the younger brother. Conclusion Mutations of CTSC gene are responsible for the phenotype of PLS.

Objective This study aimed to compare the passive fits of implant-supported cement-retained computer aided design/computer aided manufacturing (CAD/CAM) bridges fabricated with different implant superstructure designs from zirconia and titanium. Methods A total of 32 cubic clods with the same dimensions and with elastic modulus similar to that of mandibles were used. Each clod received two one-stage implants to simulate a partially edentulous jaw that was missing teeth between the lower left second premolar and second molar. Four linear strain gauges were bonded on the region surrounding each implant on the mesial, buccal, distal, and lingual aspects. A total of 32 identical frameworks were fabricated through CAD/CAM after scanning. The frameworks were allocated into four different groups (n=8) in accordance with material types and superstructure designs. Group A included zirconia ceramic implant-supported fixed prostheses with regular marginal designs. Group B comprised zirconia ceramic implant-supported fixed prostheses with full circumferential zirconia-collar marginal designs. Group C consisted of titanium ceramic implant-supported fixed prostheses with regular marginal designs. Group D included titanium ceramic implant-supported fixed prostheses with full circumferential titanium-collar marginal designs. Strain development before and after ceramic veneering was recorded during cement setting. Data were statistically analyzed by using SPSS software. Results Before ceramic veneering, material types affected the strains of prostheses, and zirconia frameworks showed lower strain than other frameworks (P<0.01). Designs affected the strains of prostheses, and frameworks with full collar marginal design showed lower strain than other frameworks (P<0.01). These two factors showed interactions (P<0.01). The strain of decorative porcelain increased after sintering. The two groups of different materials did not significantly differ (P>0.05). Nevertheless, the full circumferential collar marginal design reduced discrepancies among groups (P<0.01). Conclusion The passive fits of zirconia prostheses were better than those of titanium-based porcelain-fused-to-metal restorations. The full circumferential collar marginal design can help reduce fit inaccuracy, as well as the adverse effects of ceramic veneering.

Objective This study aims to explore the influence of three-wall osseous defects on periodontal ligament stress under normal occlusal forces. Methods A finite element model for mandibular total dentition, periodontal ligament and alveolar bone was created based on cone beam computed tomography (CBCT) DICOM images. Mesial or distal proximal three-wall osseous defects at varying depths (namely, 1/3, 2/3 and 3/3 of the root) were simulated by modifying the elastic modulus of elements within the defects area. Occlusal forces with an angle of 45° to the long axis of the tooth were applied to the finite element model. In addition, the equivalent stresses of the periodontal ligament were analysed. Results In the case of no bone defect, the mean value of the periodontal ligament equivalent stress of 14 teeth was 5.71 MPa. The equivalent stresses of the periodontal ligament at different depths (namely, 1/3, 2/3 and 3/3 of the root) were 6.61, 7.14 and 7.42 MPa, respectively. With increasing depth of the osseous defects, stress on the periodontal ligament increased considerably, and the initial stress increment was greater than that of a later stage. Periodontal ligament stresses with mesial proximal three-wall osseous defects (at depths of 1/3, 2/3 and 3/3 of the root) were 6.62, 7.19 and 7.51 MPa respectively. Periodontal ligament stresses with distal proximal three-wall osseous defects (at depths of 1/3, 2/3 and 3/3 of the root) were 6.60, 7.10 and 7.33 MPa, respectively. For three-wall osseous defects located in the mesial surface and distal surface, a significant difference in periodontal ligament stress was lacking. In the case of the same absorption depth, the size relationship of periodontal liga-ment stress was in the following order: premolars>molars>incisors>canines. Conclusion Shallow three-wall osseous defects will likely cause a notable loss in strength of the periodontal ligament. Therefore, teeth with three-wall osseous defects should become the focus of clinical research. Treatment for these teeth should be administered as early as possible.

Objective This study aimed to evaluate the effectiveness of XP-endo Finisher (XPF) file and passive ultrasonic irrigation (PUI) in the smear layer removal of the root canal. Methods A total of 60 human single-rooted premolars were selected and decoronated to standardize their canal length to 16 mm. Tooth samples were prepared using a S3 rotary system to prepare root canal with the file size of 3S and then randomly divided into 6 groups according to the final irrigation protocol, as follows: XPF 3 mL of 3% NaOCl for 1 min (group A); XPF 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% ethylene diamine tetraacetic acid (EDTA) for 1 min (group B); PUI of 3 mL of 3% NaOCl for 1 min (group C); PUI of 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% EDTA for 1 min (group D); 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle (group E); and 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle, followed by 4 mL of 17% EDTA for 1 min (group F). After the completion of the root canal preparation, the teeth were split into two longitudinally. The mean numbers of the visible open dentinal tubules in the apical and middle thirds of the root canals were evaluated via scanning electron microscope. Results The whole surfaces of the root canals in groups A, C, and E were covered by a smear layer. Groups A and C possessed significantly higher number of visible open dentinal tubules than in group E (P<0.05), with statistically insignificant difference between groups A and C (P>0.05). The apical third of the samples in groups B and D and in the middle thirds of canals in group F exhibited a small amount of smear layer, and the dentinal tubules were open or semi-open. The root canal surfaces in the apical third of the samples in group F were covered by a smear layer, and the dentinal tubules were sealed or semisealed. The smear layers in the middle third of the samples in groups B and D were removed, and the dentinal tubules were more visibly open than those of the four other groups (P<0.05). The difference between groups B and D were statistically insignificant (P>0.05). Conclusion The difference between XPF and PUI in terms of the smear layer removal of the root canals was insignificant. Hence, XPF, as a new irrigation agitation technique, can aid in improving smear layer removal.

Objective The accuracy of the occlusion vertical dimensions of edentulous Han patients from Yunnan province was compared and analyzed on the basis of cone-beam computed tomography (CBCT)-synthesized cephalograms, closest speaking space method, and interocclusal distance. Methods A database correlating the CBCT head lateral images of Han patients from Yunnan province with normal occlusal conditions was first constructed. Then, five edentulous Han patients aged 63-78 years old from Yunnan Province were selected. NNT.View software was used to measure and analyze hard tissue cephalometric radiographs that had been transformed by the CBCT marker. The radiographs were then combined with the normal population database for the assessment of occlusion vertical dimensions. The occlusion vertical dimensions determined on the basis of CBCT-synthesized cephalograms, the closest speaking space method, and the free-way space were analyzed. Results The closest speaking space method was used as the standard control group, the differences between seven methods and the closest speaking space method were analyzed. The seven methods include free-way space method and six CBCT-synthesized cephalograms methods (N-ANS/ANS-Me, S-Go/N-Me, ANS-Gn/N-ANS, ANS-FH/Me-FH, ANS-Xi-Pm, and CA/LA). The seven methods were highly consistent with the closest speaking space method (intraclass correlation coefficient>0.986). The absolute values of the differences between the methods of free-way space, N-ANS/ANS-Me, S-Go/N-Me and the closest speaking space method were lower than those of the other four groups (P<0.05), while the differences between ANS-FH/Me-FH and the closest speaking space method was higher than those other groups (P<0.05). Conclusion CBCT-synthesized cephalograms, with the exception of ANS-FH/Me-FH, can provide references for the clinical evaluation of the occlusion vertical dimensions of patients with edentulous jaws.

Objective To study the application of surgical locating guides based on cone beam computed tomography (CBCT) and computer-aided design/computer-aided manufacturing (CAD/CAM) technique on extraction of impacted super-numerary teeth. Methods This study included 15 patients with impacted supernumerary teeth in anterior maxillary. Surgical approach was determined by CBCT. Surgical locating guides of labial approach or palatal approach were designed and fabri-cated by CAD/CAM technique. Impacted supernumerary teeth were extracted under the location of surgical locating guides. Results Surgical locating guides were well attached in the operation. The impacted supernumerary teeth were located and exposed rapidly, and the adjacent important anatomical structures were avoided. Conclusion Surgical locating guides benefit the accurate detection and reduction of trauma in extraction of impacted supernumerary teeth.

Objective This study aims to observe the efficacy of vacuum sealing drainage (VSD) by continuous negative pressure drainage and saline irrigation in the treatment of oral and maxillofacial space infection. Methods Retrospective analysis was conducted on 116 cases of maxillofacial space infection, and clinical data were collected to compare the thera-peutic effects of routine incision with drainage treatment (traditional treatment group, 58 cases) and VSD treatment (VSD group, 58 cases). Results The length of hospital stay, white blood cell count, scar length, frequency of dressing change, and pain degree of patients in the VSD group were all lower than those in the traditional treatment group. Moreover, the improvement degree of mouth opening in the VSD groups was better than that in the traditional treatment group (P<0.05). Conclusion VSD is a more effective method for the treatment of oral and maxillofacial space infection.

Objective This study aimed to compare the porcelain-fused-to-metal (PFM) crown artifact in the magnetic resonance imaging (MRI) of the two magnetic resonance deartifact techniques in studying the application value of the propeller-fast spin-echo T₂-weighted sequence (FSE T2WI) in troubleshooting PFM crown artifacts. Methods A total of 48 patients with right mandible first molar crown who underwent MRI head examination were chosen as subjects in the study. According to different metal substrates, PFM crowns were divided to three types, namely, nickel-chromium alloy crown, cobalt-chromium alloy crown and titanium crown. The patients received two MRI scan sequences, that is, FSE T2WI and propeller-FSE T2WI sequences. The MRI artifacts areas in two sequences were measured. Results The difference between FSE T2WI and propeller-FSE T2WI sequences in three kinds of PFM crown was significant (P<0.05). Conclusion Propeller-FSE T2WI sequence technique can effectively reduce the metal artifacts of various PFM crowns.

Objective This work aimed to identify the risk factors of Helicobacter pylori (H. pylori) infection in preschool children and provide effective measures for the prevention and reduction of the incidence of H. pylori infections. Methods A total of 204 children from two kindergartens in Suzhou city were recruited through a questionnaire survey. Risk factors were selected through the single factor paired data χ ² test and multiple factor Logistic regression analysis. Oral and gastric H. pylori infections were detected by using H. pylori saliva detection (HPS) and ¹³C-urea breath test ( ¹³C-UBT). Special toothpaste for H. pylori control was selected for oral cleaning. Oral H. pylori infection rates at 2 months after special toothpaste treatment were examined by using HPS. Results The high-risk factors of H. pylori infections among preschool children included poor personal hygiene habits, such as the nibbling of fingers and the avoidance of hand-washing before meals, diet, and parent’s history of stomach disease. Among the 204 subjects enrolled in this study, 158 (77.45%), 37 (18.14%), and 28 (13.73%) were HPS positive, ¹³C-UBT positive, and HPS and ¹³C-UBT positive, respectively. The incidence of oral H. pylori infections was significantly higher than that of gastric H. pylori infections (P<0.01). The positive rate of infections significantly decreased after special toothpaste treatment (P<0.01). This result indicates that the intervention was effective. Conclusion Children must receive education on good eating habits. Individualized dining habits or the use of public chopsticks must be implemented. H. pylori infections must be detected as early as possible. Specific toothpaste for oral cleaning must be selected. These approaches could drastically prevent or reduce the incidence of H. pylori infections among preschool children.

Objective We aim to examine teenagers with varying vertical facial skeletal types with near-normal occlusion. We further aim to identify and study mandibular morphology and dentition characteristics to establish normal ranges and variations for future clinical reference. Methods According to the results of the case studies, 42 adolescents with near-normal occlusion were divided into three groups, namely, low- (7 cases), average- (23 cases) and high-angle (12 cases) groups. We used Invivo 5 software for Digital Imaging and Communications in Medicine (DICOM) data to calculate the cant of occlusal plane, axis corner of L6, ∠L1/MP, ∠L6/MP, Balkwill angle and Bonwill triangle of each group. Results Markedly, the finding shows that the cant of occlusal plane and axis corner of L6 in the low-angle group were smaller than those of the other two groups. In the average-angle group, ∠L1/MP was larger than that of the high-angle group. Lastly, in the high-angle group, ∠L6/MP was smaller than those of the two other groups. On the one hand, these differences were considered statistically signi-ficant (P<0.05). On the other hand, other measurements show that these differences were considered statistically non-significant (P>0.05). Conclusion In the low-angle group, the parallelisation of the occlusal plane tends to be more obvious compared with the two other groups. In the coronal section of the low-angle group, the axis of the mandibular first molar is up-right, whereas it is distally tilted in the sagittal section of the high-angle group. Furthermore, a number of differences are noted in the adult groups. Factors, such as aging and development in the craniofacial region, lead to changes in functional occlusion.

Objective This study aimed to determine the prevalence and related factors of deciduous caries in 3-5-year-old preschool children in Chongqing city. Results will be used to provide a basis for the establishment and adjustment of prevention and intervention of caries in preschool children. Methods We referred to the Fourth National Oral Health Epide-miological Survey. Data included caries prevalence in preschool children, and the questionnaires were distributed to children’ parents in Chongqing city. Results were inputted by Epidata 3.1 and statistically analyzed using SPSS 21.0. Results A total of 1 350 preschool children were included in the study. We found that maxillary deciduous central incisor and mandi-bular deciduous molars were susceptible to decay. The pre-valence of primary teeth caries in preschool children in Chong-qing city was 51.4% (694/1 350). The mean decayed-missing-filled-teeth (dmft) index was 2.34. The caries prevalence and mean dmft between age groups were statistically signi-ficant (P<0.01) and increased with age (P<0.05). However, except the 5-year-old group (P<0.05), no significant difference in caries prevalence rate and mean dmft was found between male and female children (P>0.05). Approximately 61.7% of caries cases were concentrated in a small number (36.1%) of individuals. Multivariate Logistic regression analysis showed that age, highest educational level of parents, intake frequency of sweetened beverages and carbonated drinks, toothache or similar discomfort experience over the past year, dentist visits, and parents’ assessment of teeth and oral health status of children were the factors influencing the prevalence of deciduous caries (P<0.05). Conclusion More than half of the preschool children had dental caries. Majority of caries were concentrated in a small number of individuals. The age of children, highest educational level of parents, intake frequency of sweetened beverages and carbonated drinks, toothache or discomfort experience over the past year, dentist visits, and parents’ assessment of teeth and oral health status of children were associated with the prevalence of deciduous caries.

Objective This study aimed to evaluate the risk factors of radiation-induced caries by using a multiple linear regression equation and to provide the basis for the effective prevention of radioactive caries. Methods A total of 166 patients with head and neck cancer who underwent radiotherapy were selected as subjects. The number of decayed, missing or filled surfaces were recorded. Questionnaire contents included age, sex, radiation dose, and radiotherapy techniques. Multiple step-wise regression analyses were performed to identify the risk factors of radiation-induced caries. Results Multiple stepwise regression analyses indicated that the main risk factors of radiation-induced caries were plaque index, radiotherapy techniques, time after radiotherapy, and radiotherapy dose. Conclusion The awareness of dental care and caries treatment should be improved to reduce the occurrence of radiation-induced caries in patients with head and neck cancer. In addition, intensity modulated radiation therapy should be employed to decrease the radiation exposure dose received by teeth.

Lesions on tissues and organs critically affect quality of life, due to severe tissue defects that are threatening. Tissue repair and functional reconstruction are concurrent challenges in modern medicine. Tissue engineering brings hope for tissue and organ regeneration. Scaffolds provide a microenvironment for cell growth, proliferation and differentiation. Moreover, scaffolds influence the size and morphology of regenerated tissues. Dentin matrix, which is a natural bioactive and biocompatible scaffold, has become a research hotspot in recent years and has been widely used in tissue engineering. Studies on the use of dentin matrix as scaffolds have made a series of important progress in tooth root, periodontal, dental pulp and bone regeneration. This review demonstrates the biological characteristics of dentin matrix as bioactive scaffolds, describes the application of dentin matrix in tissue regeneration and provides a theoretical basis for the use of a dentin matrix in clinical applications.

Resorption of alveolar bone that occurs following tooth extraction is irreversible, it may compromise the restoration of implants or conventional prostheses. Ridge preservation can minimize ridge resorption after tooth extraction. In this article, healing features of socket after tooth extraction, factors influencing ridge remodeling, and the use of bioma-terials were reviewed.

Epigenetics is defined as a change in gene expression without the alteration of the genetic sequence. Such a change would be inherited by offspring. Histone acetylation is a type of epigenetics. Existing studies proposed that chronic periodontitis is related to epigenetic modification. In this review, we summarised the influence of chronic periodontitis on periodontal ligament stem cells by histone acetylation.

Impacted molars are more common in maxillary and mandibular third molars, whereas impacted first molars are relatively rare. A case of horizontal impaction of mandibular first molar is reported in this study, and the relevant litera-ture are presented.

Congenital infiltrating lipomatosis of the face is a rare disorder resulting from overgrowth of adipose tissues. This condition presents gradually with swelling along with age, hypertrophy of adjacent bones, and tooth abnormalities. This study reports a case of congenital infiltrating lipomatosis of face with seizures and reviews relevant literature on the etiology, clinical symptom, diagnosis, and treatment of this condition.