Evaluation of the effect of 3D-bioprinted gingival fibroblast-encapsulated ADM scaffolds on keratinized gingival augmentation.

BACKGROUND AND OBJECTIVES: The keratinized gingiva plays an important role in maintaining healthy periodontal and peri-implant tissue. Acellular dermal matrix (ADM), as a substitute biomaterial, has a porous structure and good biocompatibility. 3D-bioprinting has the potential for tissue engineering because it enables precise loading of cells layer-by-layer. Herein, we bioprinted ADM scaffold encapsulating gingival fibroblasts (GFs) and evaluated its efficacy in keratinized gingiva augmentation in vivo to assess its potential for clinical periodontal tissue regeneration. METHODS: GFs were extracted from the gingiva of beagles and transfected with a green fluorescent protein (GFP). The ADM scaffold (ADM cell-free group) was constructed using ADM, gelatin, and sodium alginate mixed at an appropriate ratio via 3D-bioprinting. The ADM cell scaffold (ADM cell group) was established by adding extra GFs in the same manner. Six beagles were divided into blank control, ADM cell-free, and ADM cell groups; and implant surgery was performed. The keratinized gingiva was clinically and histologically evaluated at baseline and after 2 months. RESULTS: GFs transfected with GFPs expressed green fluorescence and were present in new tissue in the ADM cell group and not observed in the ADM cell-free group. At 2 months after surgery, the keratinized gingival augmentation in the ADM cell group was significantly more than that in the ADM cell-free group. Attached gingival augmentation was also observed more in the ADM cell group than that in the ADM cell-free group. Histological staining showed that the tissue in the ADM cell group displayed a more integrated structure and higher expression of COL I, COL III, and VEGF-A than those in the ADM cell-free group. CONCLUSION: 3D-bioprinted GF-encapsulated ADM scaffolds increased the amount of keratinized gingiva in vivo, suggesting that 3D-bioprinting has great potential for oral soft tissue regeneration.

Psychological impact and perceptions of orthodontic treatment of adult patients with different motivations.

INTRODUCTION: Motivations, perceptions, and psychosocial states of adult patients with orthodontic disorders in China have not been widely studied. The study assessed the psychosocial states and perceptions of adult patients undergoing orthodontic treatments with different motivations. METHODS: Two hundred forty-three adult patients (mean age, 30.2 ± 7.4 years; women, 79.0%) undergoing orthodontic treatment were recruited from a tertiary stomatology hospital. The patients answered a patient-centered questionnaire regarding motivations and perceptions of orthodontic treatment and the Psychosocial Impact of Dental Aesthetics Questionnaire. Data were analyzed using the chi-square test on the basis of multiple responses. Multiple linear regression analyses were performed to determine the association between motivation factors and the Psychosocial Impact of Dental Aesthetics Questionnaire subscale scores (P <0.05). RESULTS: Patients with various motivations were as follows: occlusal function reason (70.4%), dental esthetic reason (54.7%), facial esthetic reason (24.3%), and following others' suggestions (18.5%). Patients with esthetic or occlusal motivations exhibited significantly greater need and interest for orthodontic treatment (P <0.001). Multiple linear regression analyses revealed that the scores of social impact, psychological impact, and esthetic concern subscales were significantly associated with both dental and facial esthetic motivations (P <0.001). CONCLUSIONS: The primary motivations of Chinese patients were observed to be improved esthetics and occlusal function. Patients with esthetic or occlusal motivations exhibited significantly greater need and interest in treatment. Patients with facial or dental esthetic motivations experienced greater impacts of psychosocial states. Therefore, the patient motivations and impacts of esthetic-related psychosocial states on them should be considered during treatment.

Biomechanical evaluation of customized root implants in alveolar bone: A comparative study with traditional implants and natural teeth.

PURPOSE: To compare and evaluate density changes in alveolar bones and biomechanical responses including stress/strain distributions around customized root implants (CRIs), traditional implants, and natural teeth. MATERIALS AND METHODS: A three-dimensional finite element model of the maxillary dentition defect, CRI models, traditional restored implant models, and natural teeth with periodontal tissue models were established. The chewing load of the central incisor, the traditional implant, and the CRI was 100N, and the load direction was inclined by 11° in the sagittal plane. According to the bone remodeling numerical algorithm, the bone mineral density and distribution were calculated and predicted. In addition, animal experiments were performed to verify the feasibility of the implant design. The results of the simulation calculations were compared with animal experimental data in vivo to verify their validity. RESULTS: No significant differences in bone mineral density and stress/strain distribution were found between the CRI and traditional implant models. The animal experimental results (X-ray images and histological staining) were consistent with the numerical simulated results. CONCLUSIONS: CRIs were more similar to traditional implants than to natural teeth in terms of biomechanical and biological evaluation. Considering the convenience of clinical application, this biomechanical evaluation provides basic theoretical support for further applications of CRI.

[Mechanisms of Helicobacter pylori Intracellular Infection and Reflections Concerning Clinical Practice]. / å¹½é—¨èžºæ†èŒèƒžå† æ„ŸæŸ“æœºåˆ¶ä¸Žä¸´åºŠæ€è€ƒ.

Helicobacter pylori (H. pylori), for a long time, has generally been considered an extracellular bacterium. However, recent findings have shown that H. pylori can gain entry into host cells, evade attacks from the host immune system and the killing ability of medication, form stable intracellular ecological niche, and achieve re-release into the extracellular environment, thus causing recurrent infections. H. pylori intracellular infection causes cellular signaling and metabolic alterations, which may be closely associated with the pathogenesis and progression of tumors, thereby presenting new challenges for clinical eradicative treatment of H. pylori. Herein, examining this issue from a clinical perspective, we reviewed reported findings on the mechanisms of how H. pylori achieved intracellular infection, including the breaching of the host cell biological barrier, immune evasion, and resistance to autophagy. In addition, we discussed our reflections and the prospects of important questions concerning H. pylori, including the clinical prevention and control strategy, intracellular derivation, and the damage to host cells.

[Clinical features of autoimmune encephalitis secondary to epidemic encephalitis B in 5 children]. / 5ä¾‹æµè¡Œæ€§ä¹™åž‹è„‘ç‚Žå„¿ç«¥ç»§å‘è‡ªèº«å ç–«æ€§è„‘ç‚Žçš„ä¸´åºŠåˆ†æž.

OBJECTIVES: To study the clinical features of children with autoimmune encephalitis (AE) secondary to epidemic encephalitis B (EEB). METHODS: A retrospective analysis was performed on the medical data of five children with EEB with "bipolar course" who were treated in Children's Hospital Affiliated to Zhengzhou University from January 2020 to June 2022. RESULTS: Among the five children, there were three boys and two girls, with a median age of onset of 7 years (range 3 years 9 months to 12 years) and a median time of 32 (range 25-37) days from the onset of EEB to the appearance of AE symptoms. The main symptoms in the AE stage included dyskinesia (5/5), low-grade fever (4/5), mental and behavioral disorders (4/5), convulsion (2/5), severe disturbance of consciousness (2/5), and limb weakness (1/5). Compared with the results of cranial MRI in the acute phase of EEB, the lesions were enlarged in 3 children and unchanged in 2 children showed on cranial MRI in the AE stage. In the AE stage, four children were positive for anti-N-methyl-D-aspartate receptor antibody (one was also positive for anti-γ-aminobutyric acid type B receptor antibody), and one was negative for all AE antibodies. All five children in the AE stage responded to immunotherapy and were followed up for 3 months, among whom one almost recovered and four still had neurological dysfunction. CONCLUSIONS: EEB can induce AE, with anti-N-methyl-D-aspartate receptor encephalitis as the most common disease. The symptoms in the AE stage are similar to those of classical anti-N-methyl-D-aspartate receptor encephalitis. Immunotherapy is effective for children with AE secondary to EEB, and the prognosis might be related to neurological dysfunction in the acute phase of EEB.

Inhibitory and Injury-Protection Effects of O-Glycan on Gastric Epithelial Cells Infected with Helicobacter pylori.

Helicobacter pylori (H. pylori) is an important pathogen that can cause gastric cancer. Multiple adhesion molecules mediated H. pylori adherence to cells is the initial step in the infection of host cells. H. pylori cholesterol-α-glucosyltransferase (CGT) recognizes and extracts cholesterol from cell membranes to destroy lipid raft structure, further promotes H. pylori adhesion to gastric epithelial cells. O-Glycan, a substance secreted by the deep gastric mucosa, can competitively inhibit CGT activity and may serve as an important factor to prevent H. pylori colonization in the deep gastric mucosa. However, the inhibitory and injury-protection effects of O-Glycan against H. pylori infection has not been well investigated. In this study, we found that O-Glycan significantly inhibited the relative urease content in the coinfection system. In the presence of O-glycan, the injury of GES-1 cells in H. pylori persistent infection model was attenuated and the cell viability was increased. We use fluorescein isothiocyanate-conjugated cholera toxin subunit B (FITC-CTX-B) to detect lipid rafts on gastric epithelial cells and observed that O-glycan can protect H. pylori from damaging lipid raft structures on cell membranes. In addition, transcriptome data showed that O-glycan treatment significantly reduced the activation of inflammatory cancer transformation pathway caused by H. pylori infection. Our results suggest that O-Glycan is able to inhibit H. pylori persistent infection of gastric epithelial cells, reduce the damage caused by H. pylori, and could serve as a potential medicine to treat patients infected with H. pylori.

A prospective, multicentre study of 6-mm short implants in posterior alveolar bone supporting splinted crowns: A 5-year follow-up study.

AIM: To evaluate the clinical and radiographic outcomes of 6-mm short implants, placed in the posterior jaws and supporting splinted crowns, at 5 years after early loading. MATERIALS AND METHODS: Forty-five patients with 95 implants (diameter: 4 mm; length: 6 mm) were enrolled at three centres. Two to three implants were placed in either the maxillary or the mandibular posterior region in each patient and restored with screw-retained splinted crowns at 6 weeks later. Clinical and radiographic outcomes were evaluated at implant placement, at loading, and at 6, 12, 24, 36, and 60 months after loading. Biological and mechanical complications were recorded. Marginal changes in bone level in relation to clinical parameters were evaluated using a generalized linear mixed model. RESULTS: During the 5 years of follow-up, the mean change in the marginal bone level (MBL) was 0.04 ± 0.14 mm. Four implants in four patients were lost before loading, one implant in one patient was lost at the 5-year follow-up, and two patients were lost to follow-up. The survival and success rates were 88.4% (38/43) at the patient level. The incidence rates of peri-implant mucositis and peri-implantitis were 29.4% and 7.0%, respectively. The rate of technical complications was 14.0%. CONCLUSIONS: Over a 5-year period, 6-mm short implants supporting early loaded splinted crowns in maxillary or mandibular posterior regions showed stable MBLs and acceptable technical and biological complication rates.

Influence of different diameter reductions in the labial neck region on the stress distribution around custom-made root-analogue implants.

This study was designed to investigate the influence of diameter reductions on the stress distribution around root-analogue implants via 3D finite element analysis. Four root-analogue implant models with different diameter reductions (0, 1, 2, or 3 mm), a traditional threaded implant and congruent bone models were created through reverse engineering. A 100-N force was applied parallel with and in a 45° angle to the implant axis, respectively. The stress concentration in the labial neck area around implants with 1-2 mm diameter reduction was lower than seen with no reduction. When the implant diameter was reduced by 3 mm, there were obvious stress concentrations in both implant and bone (the maximum stress was 206  and 111 MPa, respectively). In other groups, the maximum stress was 65.1 MPa in the bone and 108 MPa in the implant. Additionally, the stress concentration in the bone around the root-analogue implant when the implant diameter was reduced by 0-2 mm (maximum stress of 65.1 MPa) was obviously smaller than that around the traditional implant (maximum stress 130.4 MPa). Reducing the diameter of maxillary central incisor root-analogue implants by up to 2 mm next to the labial cortical bone could help disperse stress.

Bromoacetic acid causes oxidative stress and uric acid metabolism dysfunction via disturbing mitochondrial function and Nrf2 pathway in chicken kidney.

Since the outbreak of COVID-19, widespread utilization of disinfectants has led to a tremendous increase in the generation of disinfection byproducts worldwide. Bromoacetic acid (BAA), one of the common disinfection byproducts in the environment, has triggered public concern because of its adverse effects on urinary system in mammals. Nevertheless, the BAA-induced nephrotoxicity and potential mechanism in birds still remains obscure. According to the detected content in the Taihu Lake Basin, the model of BAA exposure in chicken was established at doses of 0, 3, 300, 3000 µg/L for 4 weeks. Our results indicated that BAA exposure caused kidney swelling and structural disarrangement. BAA led to disorder in renal function (CRE, BUN, UA) and increased apoptosis (Bax, Bcl-2, caspase3). BAA suppressed the expression of mitochondrial biogenesis genes (PGC-1α, Nrf1, TFAM) and OXPHOS complex I genes (ND1, ND2, ND3, ND4, ND4L, ND5, ND6). Subsequently, BAA destroyed the expression of Nrf2 antioxidant reaction genes (Nrf2, Keap1, HO-1, NQO1, GCLM, GCLC). Furthermore, renal oxidative damage led to disorder in uric acid metabolism genes (Mrp2, Mrp4, Bcrp, OAT1, OAT2, OAT3) and exacerbated destruction in renal function. Overall, our study provided insights into the potential mechanism of BAA-induced nephrotoxicity, which were important for the clinical monitoring and prevention of BAA.

[Sensitivity Comparison Experiment of Four Testing Methods for Helicobacter pylori].

Objective: To measure with standard microbiology methods the sensitivity of 4 commonly used testing methods for Helicobacter pylori (Hp) and to conduct a comparative study of the correlations and differences across the 4 methods. Methods: With the Hp standard strain (SS1) as the reference, colony forming units (CFU) as the units of quantitative analysis for detection performance, and gradient dilution of SS1 suspension as the simulation sample, we measured the sensitivity of 4 Hp testing methods, including bacterial culture, rapid urease test, antigen test, and quantitative fluorescent PCR. CFU values at different concentrations corresponding to the 4 commonly used Hp testing methods were documented and the correlations and differences were analyzed accordingly. Results: The sensitivity of Hp bacterial culture, rapid urease test, antigen test and quantitative fluorescent PCR was 2.0×10 CFU/mL, 2.0×10 5 CFU/mL, 2.0×10 5 CFU/mL, and 2.0×10 2 CFU/mL, respectively. Conclusion: The testing turnover time and sensitivity of different laboratory methods for Hp testing varied significantly. The quantitative fluorescent PCR and bacterial culture both showed relatively high sensitivity, but bacterial culture has complicated operation procedures and is too time-consuming. The rapid urease test and antigen test both were simple and quick to perform, but showed low sensitivity. For clinical and laboratory testing of Hp, appropriate testing method that can identify the corresponding changes of Hp should be selected according to the actual testing purpose.

Amyloid Beta-Peptide 25-35 (Aß25-35) Induces Cytotoxicity via Multiple Mechanisms: Roles of the Inhibition of Glucosylceramide Synthase by Aß25-35 and Its Protection by D609.

Sphingolipids (SLs), such as ceramide, glucosylceramide (GlcCer), and sphingomyelin, play important roles in the normal development/functions of the brain and peripheral tissues. Disruption of SL homeostasis in cells/organelles, specifically up-regulation of ceramide, is involved in multiple diseases including Alzheimer's disease (AD). One of the pathological features of AD is aggregates of amyloid beta (Aß) peptides, and SLs regulate both the formation/aggregation of Aß and Aß-induced cellular responses. Up-regulation of ceramide levels via de novo and salvage synthesis pathways is reported in Aß-treated cells and brains with AD; however, the effects of Aß on ceramide decomposition pathways have not been elucidated. Thus, we investigated the effects of the 25-35-amino acid Aß peptide (Aß25-35), the fundamental cytotoxic domain of Aß, on SL metabolism in cells treated with the fluorescent nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-ceramide). Aß25-35 treatment reduced the formation of NBD-GlcCer mediated by GlcCer synthase (GCS) without affecting the formation of NBD-sphingomyelin or NBD-ceramide-1-phosphate, and reduced cell viability. Aß25-35-induced responses decreased in cells treated with D609, a putative inhibitor of sphingomyelin synthases. Aß25-35-induced cytotoxicity significantly increased in GCS-knockout cells and pharmacological inhibition of GCS alone demonstrated cytotoxicity. Our study revealed that Aß25-35-induced cytotoxicity is at least partially mediated by the inhibition of GCS activity.

Individual Factors of Botulinum Type A in Treatment of Gummy Smile: A Prospective Study.

BACKGROUND: Botulinum type A (BTX-A) injection is a promising treatment for gummy smile (GS), although its effects are varied and inconsistent. OBJECTIVES: The aim of this study was to explore the effect of individual factors on BTX-A treatment for GS, and to establish treatment expectations. METHODS: In this prospective clinical study, a standardized technique comprising bilateral single-point injections of 2 U BTX-A (total, 4 U) was administered to all GS patients. Data were collected at baseline and after 4, 12, and 32 weeks of follow-up. Twenty-nine potential individual factors were analyzed by correlation and regression analysis to exclude confounding bias. RESULTS: Ninety-four patients completed the BTX-A treatment. After adjusting for potential confounding factors, the correlation and regression analysis confirmed the following formula: anterior gingival exposure (GE) at 4 weeks = 1.44 + (0.94 × baseline anterior GE) - (1.88 × sex) (where male = 1 and female = 2). The confidence interval (CI) of the prediction showed that for all female participants with baseline anterior GE <5.3 mm, the 95% CI of anterior GE was 0.3 to 3.0 mm after 4 weeks of treatment, and 3.0 to 8.9 mm with baseline anterior GE ≥6 mm. For male patients with baseline anterior GEs of 3 and ≥4.6 mm, the 95% CIs were 1.5 to 3.3 mm and 3.2 to 8.9 mm, respectively. CONCLUSIONS: The effect of average-dose BTX-A treatment for GS depended on GS severity and patient's sex, rather than GS etiology and other factors. Female participants with baseline anterior GE <5.3 mm were more likely to show complete improvement after 4 weeks of treatment. However, female participants with baseline anterior GE ≥6.0 mm or male participants were less likely to show complete improvement at 4 weeks.

Influence of sagittal root positions on the stress distribution around custom-made root-analogue implants: a three-dimensional finite element analysis.

BACKGROUND: Stress concentration may cause bone resorption even lead to the failure of implantation. This study was designed to investigate whether a certain sagittal root position could cause stress concentration around maxillary anterior custom-made root-analogue implants via three-dimensional finite element analysis. METHODS: The von Mises stresses in the bone around implants in different groups were compared by finite element analysis. Six models were constructed and divided into two groups through Geomagic Studio 2012 software. The smooth group included models of unthreaded custom-made implants in Class I, II or III sagittal root positions. The threaded group included models of reverse buttress-threaded implants in the three positions. The von Mises stress distributions and the range of the stresses under vertical and oblique loads of 100 N were analyzed through ANSYS 16.0 software. RESULTS: Stress concentrations around the labial lamella area were more prominent in the Class I position than in the Class II and Class III positions under oblique loading. Under vertical loading, the most obvious stress concentration areas were the labial lamella and palatal apical areas in the Class I and Class III positions, respectively. Stress was relatively distributed in the labial and palatal lamellae in the Class II position. The maximum von Mises stresses in the bone around the custom-made root-analogue implants in this study were lower than around traditional implants reported in the literature. The maximum von Mises stresses in this study were all less than 25 MPa in cortical bone and less than 6 MPa in cancellous bone. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress concentration in the bone around the implants. CONCLUSIONS: The sagittal root position affected the von Mises stress distribution around custom-made root-analogue implants. There was no certain sagittal root position that could cause excessive stress concentration around the custom-made root-analogue implants. Among the three sagittal root positions, the Class II position would be the most appropriate site for custom-made root-analogue implants.

Anti-fatigue effects of pea (Pisum sativum L.) peptides prepared by compound protease.

In this study, the anti-fatigue effect of pea peptides in mice was explored. Mice were administrated with pea peptides for 30 days and then anti-fatigue related experiments and assays were performed. Swimming times of mice fed with pea peptides were very significantly longer than those of mice from control group in weight-loaded swimming test. Pea peptides showed very significant effect on decreasing level of blood urea nitrogen and blood lactic acid, increasing content of muscle glycogen and hepatic glycogen. Insulin level and lactate dehydrogenase activity was also improved by pea peptides treatment. Pea peptides demonstrated strong antioxidant activity in vivo test. Moreover, supplementation of pea peptides could improve immunity by increasing phagocyte activity, stimulating sIgA secretion and decreasing the pro-inflammatory cytokines in mice. These findings indicated that pea peptides had strong anti-fatigue effect in mice.

RAI3 knockdown enhances osteogenic differentiation of bone marrow mesenchymal stem cells via STAT3 signaling pathway.

Bone marrow mesenchymal stem cells (BMSCs), which have multipotential differentiation and self-renewal ability, have been becoming an attractive source of seed cells for bone tissue engineering. Nonetheless, the precise underlying mechanisms of osteogenesis of BMSCs have not been fully understood. Retinoic acid-induced gene 3 (RAI3) has been found to play important roles in mesenchymal stem cells (MSCs) adipogenesis in our previous study. However, its function in the osteogenic differentiation of BMSCs remains unknown. In this study, we found that RAI3 was significantly reduced in osteogenically differentiated BMSCs; RAI3 knockdown promoted osteogenesis of BMSCs both in vitro and in vivo. Moreover, we found RAI3 knockdown significantly upregulated the expression level of phosphorylated signal transducer and activator of transcription 3 (p-STAT3), and AG-490 which can inhibit the STAT3 signaling reversed the enhancing effect of RAI3 knockdown on the osteogenic differentiation of BMSCs. These results suggest that RAI3 plays important roles in BMSCs osteogenesis with an involvement of the STAT3 signaling, which might open a new avenue to explore BMSCs osteogenesis for the application of BMSCs in bone regeneration.

An efficient imidation of thioethers with nitrene in water.

The first imidation of thioethers with free nitrene in water was realized. N-Cbz sulfilimines are formed via imidation of thioethers with free nitrene generated from α elimination of nosyloxycarbamates. In this work, water is successfully applied as solvent for free nitrene, and transition metal catalyst is not needed.

Development and application of a triplex real-time PCR assay for simultaneous detection of avian influenza virus, Newcastle disease virus, and duck Tembusu virus.

BACKGROUND: Pathogens including duck-origin avian influenza virus (AIV), duck-origin Newcastle disease virus (NDV) and duck Tembusu virus (DTMUV) posed great harm to ducks and caused great economic losses to the duck industry. In this study, we aim to develop a triplex real-time polymerase chain reaction (PCR) assay to detect these three viruses as early as possible in the suspicious duck flocks. RESULTS: The detection limit of the triplex real-time PCR for AIV, NDV, and DTMUV was 1 × 101 copies/µL, which was at least 10 times higher than the conventional PCR. In addition, the triplex assay was highly specific, and won't cross-react with other duck pathogens. Besides, the intra-day relative standard deviation and inter-day relative standard deviation were lower than 4.44% for these viruses at three different concentrations. Finally, a total of 120 clinical samples were evaluated by the triplex real-time PCR, the conventional PCR and virus isolation, and the positive rates for these three methods were 20.83, 21.67, 19.17%, respectively. Taking virus isolation as the gold standard, the diagnostic specificity and positive predictive value of the three viruses were all above 85%, while the diagnostic sensitivity and negative predictive value of the three viruses were all 100%. CONCLUSION: The developed triplex real-time PCR is fast, specific and sensitive, and is feasible and effective for the simultaneous detection of AIV, NDV, and DTMUV in ducks.

Antimicrobial and Antifouling Polymeric Agents for Surface Functionalization of Medical Implants.

Combating implant-associated infections is an urgent demand due to the increasing numbers in surgical operations such as joint replacements and dental implantations. Surface functionalization of implantable medical devices with polymeric antimicrobial and antifouling agents is an efficient strategy to prevent bacterial fouling and associated infections. In this work, antimicrobial and antifouling branched polymeric agents (GPEG and GEG) were synthesized via ring-opening reaction involving gentamicin and ethylene glycol species. Due to their rich primary amine groups, they can be readily coated on the polydopamine-modified implant (such as titanium) surfaces. The resultant surface coatings of Ti-GPEG and Ti-GEG produce excellent in vitro antibacterial efficacy toward both Staphylococcus aureus and Escherichia coli, while Ti-GPEG exhibit better antifouling ability. Moreover, the infection model with S. aureus shows that implanted Ti-GPEG possessed excellent antibacterial and antifouling ability in vivo. This study would provide a promising strategy for the surface functionalization of implantable medical devices to prevent implant-associated infections.

Digital evaluation of absolute marginal discrepancy: A comparison of ceramic crowns fabricated with conventional and digital techniques.

STATEMENT OF PROBLEM: Marginal discrepancy is key to evaluating the accuracy of fixed dental prostheses. An improved method of evaluating marginal discrepancy is needed. PURPOSE: The purpose of this in vitro study was to evaluate the absolute marginal discrepancy of ceramic crowns fabricated using conventional and digital methods with a digital method for the quantitative evaluation of absolute marginal discrepancy. The novel method was based on 3-dimensional scanning, iterative closest point registration techniques, and reverse engineering theory. MATERIAL AND METHODS: Six standard tooth preparations for the right maxillary central incisor, right maxillary second premolar, right maxillary second molar, left mandibular lateral incisor, left mandibular first premolar, and left mandibular first molar were selected. Ten conventional ceramic crowns and 10 CEREC crowns were fabricated for each tooth preparation. A dental cast scanner was used to obtain 3-dimensional data of the preparations and ceramic crowns, and the data were compared with the "virtual seating" iterative closest point technique. Reverse engineering software used edge sharpening and other functional modules to extract the margins of the preparations and crowns. Finally, quantitative evaluation of the absolute marginal discrepancy of the ceramic crowns was obtained from the 2-dimensional cross-sectional straight-line distance between points on the margin of the ceramic crowns and the standard preparations based on the circumferential function module along the long axis. RESULTS: The absolute marginal discrepancy of the ceramic crowns fabricated using conventional methods was 115 ±15.2 µm, and 110 ±14.3 µm for those fabricated using the digital technique was. ANOVA showed no statistical difference between the 2 methods or among ceramic crowns for different teeth (P>.05). CONCLUSIONS: The digital quantitative evaluation method for the absolute marginal discrepancy of ceramic crowns was established. The evaluations determined that the absolute marginal discrepancies were within a clinically acceptable range. This method is acceptable for the digital evaluation of the accuracy of complete crowns.

Adiponectin promotes human jaw bone marrow mesenchymal stem cell chemotaxis via CXCL1 and CXCL8.

Adiponectin (APN) is known to promote the osteogenic differentiation of human jaw bone marrow mesenchymal stem cells (h-JBMMSCs). However, the underlying mechanism has not been fully elucidated. Previously, we showed that APN could promote h-JBMMSC osteogenesis via APPL1-p38 by up-regulating osteogenesis-related genes. Here, we aimed to determine whether APN could promote h-JBMMSC chemotaxis through CXCL1/CXCL8. The CCK-8, wound healing and transwell assays were used to evaluate the proliferation, migration and chemotaxis of h-JBMMSCs with or without APN treatment. Chemotaxis-related genes were screened using RNA-seq, and the results were validated using real-time PCR and ELISA. We also performed Western blot using the AMPK inhibitor, WZ4003, and the p38 MAPK inhibitor, SB203580, to identify the signalling pathway involved. We found that APN could promote h-JBMMSC chemotaxis in the co-culture transwell system. CXCL1 and CXCL8 were screened and confirmed as the up-regulated target genes. The APN-induced CXCL1/8 up-regulation to promote chemotaxis could be blocked by CXCR2 inhibitor SB225002. Western blot revealed that the phosphorylation of AMPK and p38 MAPK increased in a time-dependent manner with APN treatment. Additionally, WZ4003 and SB203580 could suppress the APN-induced overexpression of CXCL1 and CXCL8. The results of the transwell chemotaxis assay also supported the above results. Our data suggest that APN can promote h-JBMMSC chemotaxis by up-regulating CXCL1 and CXCL8.