Application of Chairside CAD/CAM and Its Influencing Factors among Chinese Dental Practitioners: a Crosssectional Study.

OBJECTIVE: To examine the increased use of chairside CAD/CAM among Chinese dental practitioners, and to explore the existing barriers influencing its further application and satisfaction levels. METHODS: A semi-structured questionnaire was developed to gather respondents' demographic information, as well as their experiences and behaviours regarding the implementation of chairside CAD/CAM. A specialised web-based survey system and WeChat were used to display and distribute the final questionnaire. Then, the data were analysed with Chi-square tests and regression analyses to determine the effects of various demographic variables on chairside CAD/ CAM applications. RESULTS: A total of 1,969 questionnaire responses were included in the analyses. Chairside CAD/ CAM systems were used by 36.9% of participants, with a higher usage rate observed among prosthodontists (60.0%) and dental practitioners holding a PhD degree (57.7%). Chairside CAD/ CAM-fabricated prostheses were most commonly used in the posterior maxilla (83.3%) and mandible (86.0%), followed by the anterior maxilla and mandible (63.8% and 48.6%, respectively). Major barriers to further application included high initial investment, frequent updates of equipment and software programs, and a lack of expertise in chairside CAD/CAM usage. CONCLUSION: Most dental practitioners did not use chairside CAD/CAM systems. The application rate was significantly influenced by sex, location, educational background, department and type of healthcare facility. Chairside CAD/CAM users showed limited satisfaction with the aesthetic performance of the fabricated prostheses. To improve the popularity of chairside CAD/CAM systems, especially among dental practitioners lacking advanced academic degrees, it is highly advisable to optimise CAD software programs and offer comprehensive training opportunities.

Interaction between the albumin-bilirubin score and nutritional risk index in the prediction of post-hepatectomy liver failure.

BACKGROUND: Post-hepatectomy liver failure (PHLF) is the most common postoperative complication and the leading cause of death after hepatectomy. The albumin-bilirubin (ALBI) score and nutritional risk index (NRI) have been shown to assess end-stage liver disease and predict PHLF and patient survival. We hypothesized that the ALBI score and NRI interact in the prediction of PHLF. AIM: To analyze the interaction between the ALBI score and NRI in PHLF in patients with hepatocellular carcinoma. METHODS: This retrospective study included 186 patients who underwent hepatectomy for hepatocellular carcinoma at the Affiliated Hospital of Youjiang Medical University for Nationalities between January 2020 and July 2023. Data on patient characteristics and laboratory indices were collected from their medical records. Univariate and multivariate logistic regression were performed to determine the interaction effect between the ALBI score and NRI in PHLF. RESULTS: Of the 186 patients included in the study, PHLF occurred in 44 (23.66%). After adjusting for confounders, multivariate logistic regression identified ALBI grade 2/3 [odds ratio (OR) = 73.713, 95% confidence interval (CI): 9.175-592.199] and NRI > 97.5 (OR = 58.990, 95%CI: 7.337-474.297) as risk factors for PHLF. No multiplicative interaction was observed between the ALBI score and NRI (OR = 0.357, 95%CI: 0.022-5.889). However, the risk of PHLF in patients with ALBI grade 2/3 and NRI < 97.5 was 101 times greater than that in patients with ALBI grade 1 and NRI ≥ 97.5 (95%CI: 56.445-523.839), indicating a significant additive interaction between the ALBI score and NRI in PHLF. CONCLUSION: Both the ALBI score and NRI were risk factors for PHLF, and there was an additive interaction between the ALBI score and NRI in PHLF.

Influence of prosthetic index structures and implant materials on stress distribution in implant restorations: a three-dimensional finite element analysis.

BACKGROUND: Mechanical complications affect the stability of implant restorations and are a key concern for clinicians, especially with the frequent introduction of new implant designs featuring various structures and materials. This study evaluated the effect of different prosthetic index structure types and implant materials on the stress distribution of implant restorations using both in silico and in vitro methods. METHODS: Four finite element analysis (FEA) models of implant restorations were created, incorporating two prosthetic index structures (cross-fit (CF) and torc-fit (TF)) and two implant materials (titanium and titanium-zirconium). A static load was applied to each group. An in vitro study using digital image correlation (DIC) with a research scenario identical to that of the FEA was conducted for validation. The primary strain, sensitivity index, and equivalent von Mises stress were used to evaluate the outcomes. RESULTS: Changing the implant material from titanium to titanium-zirconium did not significantly affect the stress distribution or maximum stress value of other components, except for the implant itself. In the CF group, implants with a lower elastic modulus increased the stress on the screw. The TF group showed better stress distribution on the abutment and a lower stress value on the screw. The TF group demonstrated similar sensitivity for all components. DIC analysis revealed significant differences between TF-TiZr and CF-Ti in terms of the maximum (P < 0.001) and minimum principal strains (P < 0.05) on the implants and the minimum principal strains on the investment materials in both groups (P < 0.001). CONCLUSIONS: Changes in the implant material significantly affected the maximum stress of the implant. The TF group exhibited better structural integrity and reliability.

An NIR-propelled janus nanomotor with enhanced ROS-scavenging, immunomodulating and biofilm-eradicating capacity for periodontitis treatment.

Periodontitis is an inflammatory disease caused by bacterial biofilms, which leads to the destruction of periodontal tissue. Current treatments, such as mechanical cleaning and antibiotics, struggle to effectively address the persistent biofilms, inflammation, and tissue damage. A new approach involves developing a Janus nanomotor (J-CeM@Au) by coating cerium dioxide-doped mesoporous silica (CeM) with gold nanoparticles (AuNPs). This nanomotor exhibits thermophoretic motion when exposed to near-infrared (NIR) laser light due to the temperature gradient produced by the photothermal effects of asymmetrically distributed AuNPs. The NIR laser provides the energy for propulsion and activates the nanomotor's antibacterial properties, allowing it to penetrate biofilms and kill bacteria. Additionally, the nanomotor's ability to scavenge reactive oxygen species (ROS) can modulate the immune response and create a regenerative environment, promoting the healing of periodontal tissue. Overall, this multifunctional nanomotor offers a promising new approach for treating periodontitis by simultaneously addressing biofilm management and immune modulation with autonomous movement.

Erythrocyte-Mimicking Nanovesicle Targeting Porphyromonas gingivalis for Periodontitis.

Porphyromonas gingivalis has been demonstrated to have the strongest association with periodontitis. Within the host, P. gingivalis relies on acquiring iron and heme through the aggregation and lysis of erythrocytes, which are important factors in the growth and virulence of P. gingivalis. Additionally, the excess obtained heme is deposited on the surface of P. gingivalis, protecting the cells from oxidative damage. Based on these biological properties of the interaction between P. gingivalis and erythrocytes, this study developed an erythrocyte membrane nanovesicle loaded with gallium porphyrins to mimic erythrocytes. The nanovesicle can target and adhere with P. gingivalis precisely, being lysed and utilized by P. gingivalis as erythrocytes. Ingested gallium porphyrin replaces iron porphyrin in P. gingivalis, causing intracellular metabolic disruption. Deposited porphyrin generates a large amount of reactive oxygen species (ROS) under blue light, causing oxidative damage, and its lethality is enhanced by bacterial metabolic disruption, synergistically killing P. gingivalis. Our results demonstrate that this strategy can target and inhibit P. gingivalis, reduce its invasion of epithelial cells, and alleviate the progression of periodontitis.

Evaluation of direct restorations for pit-and-fissure caries using stamp combined with single-shade composite resin technique: A 12-month follow-up in vivo study.

OBJECTIVES: To evaluate the clinical performance of direct restorations for pit-and-fissure caries in molars using stamp combined with single-shade composite resin (S/SCR) technique, and assess the effect of the number of stamp pressing on the trueness of S/SCR technique. METHODS: Twenty molars of fifteen patients with pit-and-fissure caries but with an intact or micro-cavitated occlusal morphology were restored using S/SCR technique and were randomly divided into single pressing group (n = 10) and double pressing group (n = 10). Intraoral scans were obtained before treatment (scan 1), after filling (scan 2) and after polishing (scan 3). Deviation distribution maps of pairwise fitting were created including comparison 1 (scan1/scan 2), comparison 2 (scan1/scan 3), and comparison 3 (scan2/scan 3) using Geomagic Control X software. Root mean square (RMS) values were calculated to evaluate the trueness of restorations. Clinical performances including esthetic, functional, and biological properties of all restorations were evaluated according to FDI criteria after a 12-month follow-up. Analysis of variance, independent-samples T test and Wilcoxon rank-sum test were used for statistical analysis (α=0.05). RESULTS: RMS values for comparison 1, comparison 2, and comparison 3 were 0.1243 ± 0.0151, 0.0966 ± 0.0136, and 0.0605 ± 0.0137 mm in single pressing group, while 0.0831 ± 0.0140, 0.0741 ± 0.0107, and 0.0475 ± 0.0099 mm in double pressing group, respectively. RMS value of single pressing group was higher than that of double pressing group in the same comparison (p ≤ 0.001). No statistically significant differences were observed between the two groups regarding esthetic, functional and biological properties (p > 0.05). For all properties, all restorations scored within 3, with over 80% scoring 1. CONCLUSION: S/SCR technique presents satisfying clinical performances for pit-and-fissure caries in molars after a 12-month follow-up. Besides, double pressing can improve the trueness of restorations compared to single pressing. CLINICAL SIGNIFICANCE: S/SCR technique is efficient in direct composite resin restoration for pit-and-fissure caries, with satisfying esthetic, functional and biological properties after a 12-month follow-up. Significantly, double pressing improves the trueness of S/SCR technique, reducing the need for occlusion adjustment.

Epinephelus coioides Sec3 promotes Singapore grouper iridovirus infection by negatively regulates immune response.

Exocyst, a protein complex, plays a crucial role in various cellular functions, including cell polarization, migration, invasion, cytokinesis, and autophagy. Sec3, known as Exoc1, is a key subunit of the Exocyst complex and can be involved in cell survival and apoptosis. In this study, two subtypes of Sec3 were isolated from Epinephelus coioides, an important marine fish in China. The role of E. coioides Sec3 was explored during Singapore grouper iridovirus (SGIV) infection, an important pathogen of marine fish which could induce 90 % mortality. E. coioides Sec3 sequences showed a high similarity with that from other species, indicating the presence of a conserved Sec3 superfamily domain. E. coioides Sec3 mRNA could be detected in all examined tissues, albeit at varying expression levels. SGIV infection could upregulate E. coioides Sec3 mRNA. Upregulated Sec3 significantly promoted SGIV-induced CPE, and the expressions of viral key genes. E. coioides Sec3 could inhibit the activation of NF-κB and AP-1, as well as SGIV-induced cell apoptosis. The results illustrated that E. coioides Sec3 promotes SGIV infection by regulating the innate immune response.

Clinical efficacy of thalidomide for various genotypes of beta thalassemia.

OBJECTIVE: The objective of this study was to investigate the therapeutic efficacy of thalidomide across various genotype presentations of ß-thalassemia so as to facilitate the early screening of thalidomide-sensitive thalassemia cases and to understand the impact of iron overload on thalidomide. METHODS: From our initial sample of 52 patients, we observed 48 patients with ß-thalassemia for two years after administration of thalidomide. This cohort included 34 patients with transfusion-dependent thalassemia (TDT) and 14 patients with non-transfusion-dependent thalassemia (NTDT). We recorded the values of hemoglobin (Hb), fetal hemoglobin (HbF), and serum ferritin (SF) in the baseline period and at 1, 3, 6, 12, 18, and 24 months after enrollment, as well as the pre- and post-treatment blood transfusion volume in all 48 cases. According to the increase in Hb levels from baseline during the 6-month observation period, the response to thalidomide was divided into four levels: main response (MaR), minor response (MiR), slow response (SLR), and no response (NR). A decrease in serum ferritin levels compared to baseline was considered alleviation of iron overload. We calculated the overall response rate (ORR) as follows: ORR = MaR + MiR + SLR/number of observed cases. RESULTS: The ORR was 91.7% (44/48 cases), and 72.9% showed MaR (35/48 cases). Among the 34 patients with TDT, 21 patients (61.8%) were free of blood transfusion, and the remaining 13 patients still required blood transfusion, but their total blood transfusion volume reduced by 31.3% when compared to the baseline. We found a total of 33 cases with 10 combinations of advantageous genes, which included 5 cases with ßCD41-42/ßCD17 and 6 cases with ßCD41-42/ß-28. Based on the treatment outcomes among the 48 cases in the observation group, there were 33 cases in the MaR group and 15 cases in the SLR/NR group. There was a difference in HbF between the two groups at baseline (P = 0.041). There were significant differences between the two groups in Hb and HbF at the time points of 6 and 12 months, respectively (P < 0.001). Compared to the baseline measurement, there was a significant decrease in the level of SF at months 12 and 24 (P < 0.001). CONCLUSION: In this study, we identified 10 ß-thalassemia gene combinations that were sensitive to thalidomide. These gene combinations can be used for initial screening and to predict the therapeutic effect of thalidomide in clinical practice. We examined the therapeutic response to thalidomide and found that the administration of thalidomide in combination with standardized iron removal was more beneficial in reducing iron overload.

Esthetic rehabilitation of labial tooth defects caused by caries of the anterior teeth using a composite resin injection technique with veneer-shaped 3D printing indices.

PATIENTS: An 18-year-old woman sought treatment for caries of the anterior teeth after completing orthodontic treatment. Direct composite resin restoration was chosen because the patient preferred a minimally invasive and cost-effective treatment whenever possible. Based on diagnostic wax-up, veneer-shaped indices for composite resin injection were designed to replicate and restore tooth defects rapidly and accurately. The overall esthetic result was excellent after a 1-year of follow-up. DISCUSSION: Direct freehand composite resin restorations are clinically challenging. The recently proposed 3D printing index for the composite resin injection technique is helpful for direct restoration but is challenging to remove. The veneer-shaped indices avoid the formation of an undercut in the direction of removing the index, making them easy to remove after finishing the restorations. CONCLUSIONS: Using veneer-shaped indices for composite resin injection enables rapid esthetic rehabilitation of labial tooth defects caused by caries. This approach reduces chairside time and operational difficulty while allowing for easy index removal after completing the restorations.

Different surface treatments and adhesive monomers for zirconia-resin bonds: A systematic review and network meta-analysis.

This review examined the efficacy of surface treatments and adhesive monomers for enhancing zirconia-resin bond strength. A comprehensive literature search in PubMed, Embase, Web of Science, Scopus, and the Cochrane Library yielded relevant in vitro studies. Employing pairwise and Bayesian network meta-analyses, 77 articles meeting inclusion criteria were analyzed. Gas plasma was found to be ineffective, while treatments including air abrasion, silica coating, laser, selective infiltration etching, hot etching showed varied effectiveness. Air abrasion with finer particles (25-53 µm) showed higher immediate bond strength than larger particles (110-150 µm), with no significant difference post-aging. The Rocatec silica coating system outperformed the CoJet system in both immediate and long-term bond strength. Adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) were superior to other acidic monomers. The application of 2-hydroxyethyl methacrylate and silane did not improve bonding performance. Notably, 91.2 % of bonds weakened after aging, but this effect was less pronounced with air abrasion or silica coating. The findings highlight the effectiveness of air abrasion, silica coating, selective infiltration etching, hot etching, and laser treatment in improving bond strength, with 10-MDP in bonding agents enhancing zirconia bonding efficacy.

Landform and lithospheric development contribute to the assembly of mountain floras in China.

Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the 'floristic geo-lithology hypothesis', which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.

Nutrient requirements determined by grain yield and protein content to optimize N, P, and K fertilizer management in China.

Nutrient requirement for crop growth, defined as the amount of nutrient that crops take up from soil to produce a specific grain yield, is a key parameter in determining fertilizer application rate. However, existing studies primarily focus on identifying nitrogen (N), phosphorus (P), and potassium (K) requirements solely in relation to grain yield, neglecting grain protein content, a crucial index for wheat grain quality. Addressing this gap, we conducted multi-site, multi-cultivar, and multi-year field trials across three ecological regions of China from 2016 to 2020 to elucidate variations in nutrient requirements for grain yield and grain protein. The research findings revealed that wheat grain yield ranged from 4.1 to 9.3 Mg ha-1 (average 6.9 Mg ha-1) and grain protein content ranged from 98 to 157 g kg-1 (average 127 g kg-1) across the three regions. Notably, the N requirement exhibited a nonlinear correlation with the wheat grain yield but a linear increase with increasing grain protein, while the P and K requirements positively correlated with grain yield and protein content. Regression models were formulated to determine the nutrient requirements (MENR), enabling the prediction of N, P, and K requirements for leading cultivars with varying grain yields and protein contents. Implementing nutrient requirements based on MENR projections resulted in substantial reductions in fertilizer rates: 22.0 kg ha-1 N (10.7 %), 9.9 kg ha-1 P (20.2 %), and 8.1 kg ha-1 K (16.3 %). This translated to potential savings of 0.4 Mt. N, 0.23 Mt. P, and 0.17 Mt. K, consequently mitigating 5.5 Mt. CO2 greenhouse-gas emission and yielding an economic benefit of 0.8 billion US$ annually in China. These findings underscore the significance of considering grain yield and protein content in estimating nutrient requirements for fertilizer recommendations to realize high-yielding, high-protein wheat production, and minimize overfertilization and associated environmental risks.

Does an incomplete ferrule affect the fracture of endodontically treated teeth? A systematic review of in vitro studies.

OBJECTIVE: The purpose of this systematic review was to assess the impact of the incomplete ferrule on the fracture of endodontically treated teeth (ETT). DATA: The keywords such as "incomplete ferrule," "ferrule," "ferrule effect," "residual dentin," "remaining dentin," or "remaining coronal dentin" were used for searching, and only in vitro studies investigating the incomplete ferrule effect on natural teeth were included. SOURCES: PubMed, Medline, Embase, Cochrane Library, and Science Direct databases, and manual-searching. STUDY SELECTION: The search strategy yielded 1633 hits, and a total of 19 in vitro studies closely related to the effect of incomplete ferrule on ETT were included. CONCLUSION: The presence of an incomplete ferrule may significantly increase the fracture resistance of restored ETT, compared with restored ETT without ferrule. The number of residual axial walls of the incomplete ferrule may have an impact on the fracture resistance and fracture mode. The location of residual axial walls of the incomplete ferrule may affect the fracture resistance but not the fracture mode. CLINICAL IMPLICATIONS: Limited data suggest that the presence of incomplete ferrule has a positive effect on the fracture resistance of restored ETT. An incomplete ferrule can be an alternative for restoring ETT when a complete ferrule is not present. Nevertheless, further high-quality studies are still needed to offer more robust evidence and to take potential confounding factors into account.

Advances in ceramics for tooth repair: From bench to chairside.

OBJECTIVES: To give a comprehensive review of advancement in dental ceramics, fabrication methods, and the challenges associated with clinical application. DATA, SOURCES AND STUDY SELECTION: Researches on chemical composition, biomechanical behaviors, optical properties, bonding strategies and fabrication methods were included. The search of articles was independently conducted by two authors in the PubMed, Scopus, Medline and Web of Science. CONCLUSIONS: Dental ceramics have shown significant advancements in terms of esthetics and function. However, improving fracture toughness without compromising optical properties remains a challenge. Repairing fractured zirconia or glass-matrix ceramic prostheses with the same material is difficult due to the sintering process. Developing innovative bonding techniques that provide strong and long-lasting bonding strength between ceramics and tooth structures poses a recurring obstacle. CLINICAL SIGNIFICANCE: Despite the emergence of dental ceramics and fabrication techniques, certain limitations such as susceptibility to brittleness and fracture still exist. Therefore, the current review provided valuable information around the advanced dental ceramics in tooth repair. The laboratory test data and the clinical outcome are also presented in details, aiming to guide clinicians in making informed decisions regarding ceramic restorations.

Application of deep learning in isolated tooth identification.

BACKGROUND: Teeth identification has a pivotal role in the dental curriculum and provides one of the important foundations of clinical practice. Accurately identifying teeth is a vital aspect of dental education and clinical practice, but can be challenging due to the anatomical similarities between categories. In this study, we aim to explore the possibility of using a deep learning model to classify isolated tooth by a set of photographs. METHODS: A collection of 5,100 photographs from 850 isolated human tooth specimens were assembled to serve as the dataset for this study. Each tooth was carefully labeled during the data collection phase through direct observation. We developed a deep learning model that incorporates the state-of-the-art feature extractor and attention mechanism to classify each tooth based on a set of 6 photographs captured from multiple angles. To increase the validity of model evaluation, a voting-based strategy was applied to refine the test set to generate a more reliable label, and the model was evaluated under different types of classification granularities. RESULTS: This deep learning model achieved top-3 accuracies of over 90% in all classification types, with an average AUC of 0.95. The Cohen's Kappa demonstrated good agreement between model prediction and the test set. CONCLUSIONS: This deep learning model can achieve performance comparable to that of human experts and has the potential to become a valuable tool for dental education and various applications in accurately identifying isolated tooth.

A digital guide device to facilitate CAD-CAM veneer cementation for mandibular incisors: A dental technique.

The novel design of a digital guide to facilitate the cementation of computer-aided design and computer-aided manufacturing (CAD-CAM) veneers for mandibular incisors by using a polymer infiltrated ceramic network (PICN) material is described. This guide provided an efficient, reliable, and accurate approach to facilitating multiple veneers with minimally invasive preparation during cementation, reducing the technique sensitivity of freehand practice and chairside time.

Association of periodontitis with gastrointestinal tract disorders: A bidirectional Mendelian randomization study.

BACKGROUND: The bidirectional link of periodontitis (PD) and gastrointestinal tract (GIT) disorders has been investigated in previous epidemiological studies; however, the conclusions still remain controversial. The aim of this study was to comprehensively explore the bidirectional causal effect between PD and various GIT diseases. METHODS: Based on summary-level data of genome-wide association studies (GWASs), a two-sample bidirectional Mendelian randomization (MR) study was undertaken. Single-nucleotide polymorphisms (SNPs) associated with PD or GIT disorders (chronic gastritis [CG], gastric ulcer [GU], duodenal ulcer [DU], gastroesophageal reflux disease [GERD], irritable bowel syndrome [IBS], and diverticular disease of the intestine [DI]) in GWASs were applied as exposure. The primary method employed was the inverse-variance weighted (IVW) method, and several sensitivity analyses were performed to investigate potential pleiotropy. RESULTS: With regard to the investigation of the causality between PD and GIT disorders, the IVW method revealed that there is a causal impact of PD on GU (odds ratio [OR] 1.088; 95% confidence interval [CI], 1.036-1.141; adjusted p = 0.004) and DI (OR 0.938; 95% CI, 0.911-0.965; adjusted p = 0.000). However, no significant genetic liability was observed for the causal effect of PD on CG, DU, GERD, and IBS. Furthermore, the primary analysis did not demonstrate a causal effect of GIT disorders on PD. CONCLUSION: This MR study suggests that PD may be associated with an increased risk of GU and a reduced risk of DI, with possibly limited clinical relevance. Further studies are needed to support the conclusions of this MR study.

IRX5 suppresses osteogenic differentiation of hBMSCs by inhibiting protein synthesis.

In our previous study, IRX5 has been revealed a significant role in adipogenesis of hBMSCs. Considering the expansion of adipose tissue in bone marrow in aged and ovariectomy-related osteoporosis, the effect of IRX5 on the osteogenesis of BMSCs still needs to be elucidated. In vivo, models of aging-induced and ovariectomy-induced osteoporotic mice, and in vitro studies of IRX5 gene gain- and loss-of-function in hBMSCs were employed. Histology, immunofluorescence, qRT-PCR, and Western blot analysis were performed to detect the functions of IRX5 in hBMSCs osteogenic differentiation. RNA-seq, transmission electron microscopy, Seahorse mito-stress assay, and Surface Sensing of Translation assay were conducted to explore the effect of mammalian/mechanistic target of rapamycin (mTOR)-mediated ribosomal translation and mitochondrial functions in the regulation of hBMSCs differentiation by IRX5. As a result, elevated IRX5 protein expression levels were observed in the bone marrow of osteoporotic mice compared to normal mice. IRX5 overexpression attenuated osteogenic processes, whereas IRX5 knockdown resulted in enhanced osteogenesis in hBMSCs. RNA-seq and enrichment analysis unveiled that IRX5 overexpression exerted inhibitory effects on ribosomal translation and mitochondrial functions. Furthermore, the application of the mTOR activator, MHY1485, effectively reversed the inhibitory impact of IRX5 on osteogenesis and mitochondrial functions in hBMSCs. In summary, our findings suggest that IRX5 restricts mTOR-mediated ribosomal translation, consequently impairing mitochondrial OxPhos, which in turn results in osteogenic dysfunction of hBMSCs.

The research on the particle concentration distribution of directed airflow in cleanrooms for operators.

Existing research of non-unidirectional cleanrooms generally suggests that lower-side return air outlets provide better control effect on indoor particle concentration. As a result, there has been relatively less focus on return air outlets. However, installing return air outlets oriented towards operators as particle emission sources can reduce the impact on process layout and improve space utilization, while also provide less impact from upper particle emission sources on the workbench area. To investigate the characteristics of return air outlet for operators (abbreviated as H), this study compared the particle concentration distribution, non-uniformity, and purification efficiency of return air oultet H and the traditional lower-side (abbreviated as L) return air outlets by experiments and CFD simulations. Based on the theory of mass conservation, the expression of required air supply volume under equivalent cleanroom conditions was derived. Under corresponding experimental and simulation conditions, the particle concentration differences range from 2.0% to 12.7% for return air outlet H and from 12.4% to 33.2% for return air outlet L, and these differences gradually decrease with the air exchange rate (ACH) increases. The results show that ACH = 20 is sufficient for cleanliness requirements with return air outlet H when there is one person in the cleanroom, while a higher rate of ACH = 35 is needed when there are two persons. Although lower-side return air outlets have certain potential for reducing particle concentration in the cleanroom, increasing the air exchange rate remains the most effective method to control indoor particle concentration. Compared to the traditional lower-side return air outlet L, the ranges of the non-uniformity coefficients for return air outlet H and L are 0.50 to 0.67 and 0.45 to 0.53, respectively. The average non-uniformity coefficient differs by 11.9%, and there is not a significant difference in uniformity with more than 20 air changes per hour. The use of return air outlets H only requires an additional 11% of air supply volume to achieve the same cleanliness, demonstrating its effectiveness in controlling particle concentration. It is suitable for cleanrooms with higher requirements for workbenches and for cleanrooms with restricted floor usage or requiring flexible layouts. The study also explores the impact of width of return air outlet oriented towards operators as particle emission sources, the results show that the larger-sized outlets facilitate the particle discharge and control the particle distribution inside the room.

Effect of aging and bleaching on the color stability and surface roughness of a recently introduced single-shade composite resin.

OBJECTIVES: To assess the effects of aging and bleaching procedures on the color stability and surface roughness of a new single-shade composite versus multi-shade composite resins. METHODS: A single-shade composite resin (Charisma Diamond One, CDO) and 3 multi-shade composite resins (Tetric NCeram, Filtek Z350 XT, Clearfil Majesty Posterior) were tested. Thirty specimens of each material were subjected to one of the aging procedures respectively: immersion in distilled water (12 days/37 °C), immersion in coffee (12 days/37 °C), or water thermocycling (10,000 cycles/5-55 °C). All specimens underwent in-office bleaching after aging. Kruskal-Wallis tests and analysis of variance were used for statistical analysis (α=0.05). RESULTS: All materials exhibited a change of color (ΔE00), translucency (RTP), whiteness (WID) and surface roughness parameters (Sa,Sv) after aging and bleaching procedures. CDO showed the highest ΔE00 among all resins with the highest RTP value, regardless of the aging procedures. Immersion in coffee led to the significantly highest ∆E00 values and lowest RTP values for nearly all resins. Positive ΔWID1 (WID(bleaching)-WID(baseline)) values were found in distilled water immersion and thermocycling groups, while negative ΔWID1 values were found in the coffee immersion group for all materials. Besides, positive ΔWID2 (WID(bleaching)-WID(aging)) values were found in all aging groups for nearly all materials. All materials showed an increasing trend in Sa and Sv after bleaching. CONCLUSIONS: CDO showed more pronounced discoloration than multi-shade composite resins. Although the whiteness of all resins increased after bleaching, none was completely restored in the coffee immersion group. Bleaching significantly increased the surface roughness of all materials. CLINICAL SIGNIFICANCE: Charisma Diamond One is more susceptible to discoloration, which may affect its long-term success rate. Bleaching could partially reduce the color change of the composite resins but did not return them completely to their original state. The roughness of the resins increased after bleaching, prompting dentists to repolish them after bleaching.