Novel TFG mutation causes autosomal-dominant spastic paraplegia and defects in autophagy.

BACKGROUND: Mutations in the tropomyosin receptor kinase fused (TFG) gene are associated with various neurological disorders, including autosomal recessive hereditary spastic paraplegia (HSP), autosomal dominant hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) and autosomal dominant type of Charcot-Marie-Tooth disease type 2. METHODS: Whole genome sequencing and whole-exome sequencing were used, followed by Sanger sequencing for validation. Haplotype analysis was performed to confirm the inheritance mode of the novel TFG mutation in a large Chinese family with HSP. Additionally, another family diagnosed with HMSN-P and carrying the reported TFG mutation was studied. Clinical data and muscle pathology comparisons were drawn between patients with HSP and patients with HMSN-P. Furthermore, functional studies using skin fibroblasts derived from patients with HSP and patients with HMSN-P were conducted to investigate the pathomechanisms of TFG mutations. RESULTS: A novel heterozygous TFG variant (NM_006070.6: c.125G>A (p.R42Q)) was identified and caused pure HSP. We further confirmed that the well-documented recessively inherited spastic paraplegia, caused by homozygous TFG mutations, exists in a dominantly inherited form. Although the clinical features and muscle pathology between patients with HSP and patients with HMSN-P were distinct, skin fibroblasts derived from both patient groups exhibited reduced levels of autophagy-related proteins and the presence of TFG-positive puncta. CONCLUSIONS: Our findings suggest that autophagy impairment may serve as a common pathomechanism among different clinical phenotypes caused by TFG mutations. Consequently, targeting autophagy may facilitate the development of a uniform treatment for TFG-related neurological disorders.

Postpartum symptoms of anxiety, depression and stress: differential relationships to women's cortisol profiles.

PURPOSE: Women are at high risk of stress, anxiety, and depression during the postpartum but the ways in which these different types of psychological distress are related to cortisol regulation is not clear. We examined the distinct association of each type of distress with women's average cortisol level, cortisol awakening response (CAR), cortisol decline across the day (diurnal slope), and overall amount of cortisol secretion across the day (AUCG). METHODS: At 6 months postpartum, a diverse group of 58 women completed measures of depression, anxiety, perceived stress, and life stressors. Each woman provided 4 salivary samples for cortisol assay from waking to bedtime on each of 2 consecutive days. Linear regressions were used to examine associations of stress, anxiety and depression to each of the 4 cortisol measures, controlling for number of stressful life events. RESULTS: Depressive symptoms were associated with less of a rise in the CAR (ß = -.46, p = 0.01), steeper diurnal slope (ß = .51, p = 0.006), and higher average cortisol level (ß = .42, p = .01). Women who met the clinical cutoff for an anxiety disorder had lower overall cortisol output (ß = -.29, p = 0.03). Stress was not related to any cortisol metric. CONCLUSIONS: Findings suggest that stress is less associated with cortisol alterations in the postpartum than are more severe types of psychological distress. Anxiety and depression may have distinct and opposite profiles of cortisol dysregulation. Results indicate that mental health assessment is critical even in the later postpartum so that interventions can be initiated to reduce emotional suffering and the risk of impaired cortisol regulation.

Mechanical loading and autophagy: A study on the BoNT-A injection-induced condylar cartilage degeneration.

Botulinum toxin A (BoNT-A) has emerged as a treatment option for temporomandibular disorder (TMD). By injecting BoNT-A into the masseter muscle, it is possible to reduce mechanical loading on the temporomandibular joint (TMJ). However, numerous prior studies have indicated excessive reduction in mechanical loading can have detrimental effects on TMJ cartilage. This study proposes that autophagy, a process influenced by mechanical loading, could play a role in BoNT-A-induced mandibular condyle cartilage degeneration. To explore this hypothesis, we employed both BoNT-A injection and an excessive biting model to induce variations in mechanical loading on the condyle cartilage of C57BL/6 mice, thereby simulating an increase and decrease in mechanical loading, respectively. Results showed a significant reduction in cartilage thickness and downregulation of Runt-related transcription factor 2 (Runx2) expression in chondrocytes following BoNT-A injection. In vitro experiments demonstrated that the reduction of Runx2 expression in chondrocytes is associated with autophagy, possibly dependent on decreased YAP expression induced by low mechanical loading. This study reveals the potential involvement of the YAP/LC3/Runx2 signaling pathway in BoNT-A mediated mandibular condylar cartilage degeneration.

A Europium Metal-Organic Framework and Its Polymer Composite Membrane as Switch-Off Fluorescence Sensors for Antibiotic Detection in Lake Water.

The detection of antibiotic residues is of great significance in monitoring their overuse in healthcare, livestock and poultry farming, and agricultural production. Herein, EuCl3 and 4,4'-dicarboxyl-diphenoxyethene (H2DPOE) ionothermally reacted in 1-methyl-3-butylimidazolium chloride to give a europium metal-organic framework (Eu-DPOE). Eu-DPOE shows different fluorescence quenching rates for sensing eight antibiotics under different excitation wavelengths. Eu-DPOE displays a fast response, high selectivity, and sensitivity in antibiotic detection by fluorescence quenching. Eu-DPOE can sensitively detect TCs (tetracyclines), NOR (norfloxacin), NFT (furazolidone), ODZ (ornidazole), SDZ (sulfadiazine), and CHL (chloramphenicol) with limits of detection below 0.5 µmol/L. It provides a convenient and rapid tool for sensing antibiotics in aqueous solution. The detection mechanism is a competition absorption between DPOE2- and antibiotics with the supports from powder X-ray diffraction (PXRD), UV-vis spectra, and fluorescence lifetime. With a composite membrane of poly(vinylidene fluoride) (PVDF) matrix loading Eu-DPOE (Eu-DPOE@PVDF), Eu-DPOE@PVDF exhibits a visual fluorescence response to NOR under a 254 nm UV lamp and NFT and CTC under 365 nm. Eu-DPOE@PVDF is applied in the quantitative detection of CTC, NOR, and NFT in lake water with recovery rates ranging from 88.37 to 113.8%. Totally, fluorescence-quenched Eu-DPOE@PVDF exhibits a fast response, high selectivity, and sensitivity in sensing CTC, NOR, and NFT.

Preparation of three-dimensional matrices of human gingival tissue and comparison of induction of mesenchymal and blastema stem cell behaviors in prepared scaffolds.

This study aimed to compare the behavior of rat bone marrow mesenchymal stem cells and rabbit auricle blastema cells implanted in non-cellular gingival tissue scaffold of human. In this regard, the tissues obtained from gingival surgeries in the dental clinic were de-cellulated using two detergents of sodium dodecyl sulfate and triton 100-X. After washing and sterilization, they were used as a scaffold for culture with bone marrow mesenchymal stem cells of rats. Using light and electron microscopy, these scaffolds were examined before and after 1, 2, and 4 weeks of cell culture. Also, the prepared three-dimensional scaffold was placed in the blastema ring obtained from the rabbit earlobe punch. The samples were evaluated 1, 2, and 4 weeks after culture based on histology techniques. The results showed that the study of scaffolds by electron microscopy showed preserving the epithelium matrix and the collagen fibers in the tissue. Structures similar to the epithelium were created in both samples. In addition, induction of cellular secretion was observed in scaffold cells migrating to the scaffold. In general, scaffolds made from human gums can be a good platform for studying cellular behaviors. Of course, further experiments to determine the nature of differentiated cells can help advance our knowledge of matrix cell interactions.

Predicting the risk of dental implant loss using deep learning.

AIM: To investigate the feasibility of predicting dental implant loss risk with deep learning (DL) based on preoperative cone-beam computed tomography. MATERIALS AND METHODS: Six hundred and three patients who underwent implant surgery (279 high-risk patients who did and 324 low-risk patients who did not experience implant loss within 5 years) between January 2012 and January 2020 were enrolled. Three models, a logistic regression clinical model (CM) based on clinical features, a DL model based on radiography features, and an integrated model (IM) developed by combining CM with DL, were developed to predict the 5-year implant loss risk. The area under the receiver operating characteristic curve (AUC) was used to evaluate the model performance. Time to implant loss was considered for both groups, and Kaplan-Meier curves were created and compared by the log-rank test. RESULTS: The IM exhibited the best performance in predicting implant loss risk (AUC = 0.90, 95% confidence interval [CI] 0.84-0.95), followed by the DL model (AUC = 0.87, 95% CI 0.80-0.92) and the CM (AUC = 0.72, 95% CI 0.63-0.79). CONCLUSIONS: Our study offers preliminary evidence that both the DL model and the IM performed well in predicting implant fate within 5 years and thus may greatly facilitate implant practitioners in assessing preoperative risks.

Selective laser sintering versus conventional lost-wax casting for single metal copings: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Evidence comparing the marginal and internal fit of single metal copings fabricated via selective laser sintering and conventional lost-wax casting is inadequate. PURPOSE: The purpose of this systematic review was to compare the fit of single metal copings fabricated via selective laser sintering and lost-wax casting. Moreover, the effects of different variables on fit accuracy were determined. MATERIAL AND METHODS: Google Scholar, ScienceDirect, SpringerLink, and Wiley databases were searched electronically as well as manually. The mean absolute marginal gap, marginal gap, internal gap, axial gap, and occlusal gap values of single metal copings fabricated via selective laser sintering and lost-wax casting were statistically analyzed to determine and evaluate the factors affecting the fit accuracy (α=.05). RESULTS: Single metal copings fabricated via selective laser sintering had mean absolute marginal gaps and occlusal gaps similar to those of copings fabricated via lost-wax casting, based on a subgroup meta-analysis of gaps evaluated using stereomicroscopy (P>.05). The fit of single metal copings was not affected by the type of tooth (P>.05). The conventional impression, the indirect digital scan, and the direct digital scan led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via lost-wax casting (P>.05). The indirect and direct digital scans led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via selective laser sintering (P>.05). Printed wax patterns provided significantly smaller mean axial gap values than milled plastic or milled wax patterns for the copings fabricated via lost-wax casting (P<.05). Printed, milled, and conventional wax patterns had similar mean marginal gaps and internal gaps for the copings fabricated via lost-wax casting (P>.05). For single copings fabricated via lost-wax casting, Ni-Cr and Co-Cr had similar mean internal gaps (P>.05). CONCLUSIONS: No statistically significant differences were found between single metal copings fabricated via selective laser sintering and lost-wax casting. Selective laser sintering can satisfy the clinical requirement for single metal copings.

Adjuvant Chemotherapy with Chinese Herbal Medicine Formulas Versus Placebo in Patients with Lung Adenocarcinoma after Radical Surgery: a Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: The toxicity and side effects caused by adjuvant chemotherapy (ACT) after radical surgery for lung adenocarcinoma (LAC) lead to early termination frequently. This study was conducted to provide an objective basis for the effect of Chinese herbal medicine formulas (CHMFs) combined with chemotherapy in reducing toxicity and enhancing efficacy of ACT. METHOD: From February 17th, 2012 to March 20th, 2015, 233 patients from 7 hospitals diagnosed with LAC in IB~IIIA stage were randomly assigned into ACT + CHMF group (116 patients) and ACT + placebo group (117 patients). CHMF was taken orally until the end of chemotherapy. Chemotherapy-related toxic, side effects were investigated as the primary outcome. Disease-free survival (DFS) and overall survival (OS) were used as the secondary outcome. RESULTS: At one week following chemotherapy, the incidence of dry mouth, diarrhea and thrombocytopenia significantly decreased in CHMF group (P = 0.017, P = 0.033, P = 0.019, respectively). At two weeks following chemotherapy, fatigue and diarrhea were more obvious in the placebo group (P = 0.028, P = 0.025, respectively). In addition, patients in the CHMF group showed an increase in median DFS from 37.1 to 51.5 months compared with placebo group although there was no statistical significance (P = 0.16). In the stage IB subgroup, the CHMF group had a significantly better DFS (HR (95% CI) = 0.53 (0.28-0.99), P = 0.046). There was no significant difference in OS between the groups (P = 0.72). CONCLUSION: For patients with LAC, ACT combined with CHMF after radical surgery can prolong the DFS time especially in the early stage, and reduces the chemotherapy-related toxic and side effects. TRIAL REGISTRATION: NCT01441752. Registered 14 July, 2011.

Laccase production by Trametes versicolor in solid-state fermentation using tea residues as substrate and its application in dye decolorization.

An efficient valorization of tea residues into value-added product was developed by Trametes versicolor in solid-state fermentation (SSF). The laccase production of 25.7 U/g dry substrate was obtained by optimizing culture medium and condition, resulting in a 4.0-fold increase compared to that of 6.4 U/g dry substrate under unoptimized condition. During the 7-day cultivation under SSF, 44.7%, 12.2% and 9.8% degradation occurred for lignin, hemicellulose and cellulose in tea residues, respectively. Laccase production reached 31.2 U/g dry substrate by the scaling-up culture in shallow tray system. The dry fermented tea residues were directly used as crude enzyme in the decolorization of malachite green. It possessed a decolorization rate of more than 95% within 120 min and remained 81.3% of decolorization capacity after 6 cycles. The present study provided a useful strategy for low-cost laccase production by SSF and it exhibited great potential for the application in dye decolorization.

Short versus standard implants for single-crown restorations in the posterior region: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Whether implant-supported crowns on short or standard implants have similar clinical outcomes in the posterior alveolar bone is unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to compare clinical outcomes, including survival rates, marginal bone loss (MBL), and complications associated with short implants and standard implants supporting a single crown in the posterior alveolar bone. MATERIAL AND METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles and was registered with PROSPERO (CRD42018112978). The authors identified eligible trials published before August 2019 by searching PubMed, EMBASE, and the Cochrane Library. Only randomized controlled trials (RCTs) were included in the study, and quality assessment was performed by using the Cochrane Collaboration Risk of Bias tool. Relevant information was extracted by using a standardized form, and a meta-analysis was performed by using a software program. RESULTS: A total of 1954 references were identified. Five eligible trials were included in the quantitative synthesis. The survival rate of the short implants (≤6 mm) was similar to that of longer implants (>6 mm) in the short term (P=.72; RR: 0.99; 95% CI: 0.97-1.02); however, long-term follow-up showed that short implants had a poorer survival rate than standard implants (P=.01; RR: 0.94; 95% CI: 0.90-0.99). There was no significant difference in the MBL (P=.94; MD: 0.00; 95% CI: -0.10 to 0.11). CONCLUSIONS: The present study suggested that, although short implants have a higher crown-to-implant (C/I) ratio, they do not affect MBL. However, long-term follow-up comparisons indicated that short implants (≤6 mm) have a poorer survival rate than standard implants (>6 mm) (P=.01). Nonsplinted crowns supported by short implants should be used with caution in the posterior alveolar bone.

Flame Retardant Paraffin-Based Shape-Stabilized Phase Change Material via Expandable Graphite-Based Flame-Retardant Coating.

Shape-stabilized phase change material (SSPCM) is a promising thermal energy storage material in energy-saving buildings. However, its flammability leads to a fire risk. The conventional bulk addition method has a limited flame-retardant effect. Herein, a series of surface coatings with various flame retardants were introduced to improve flame retardance of SSPCM. The results showed that all of the coatings had flame-retardant effects on SSPCM; In particular, the EG coating performed the best: the horizontal burning time was the longest, the limiting oxygen index was above 30%, the V0 classification was obtained, the peak heat release rate was sharply decreased from 1137.0 to 392.5 kW/m2 and the burning process was prolonged with the least total smoke production. The flame-retardant mechanism was discussed. As paraffin easily evaporated from the SSPCM at a moderate temperature, it caused flames. After being surface coated, the EG-based coatings first hindered the volatilization of paraffin at a moderate temperature, then expanded and formed thick porous carbon layers at a high temperature to block the transfer of combustibles, oxygen and heat between the bulk and the environment. Therefore, the surface coating strategy achieved a desirable flame-retardant level with fewer flame retardants.

Interconnected Microdomain Structure of a Cross-Linked Cellulose Nanocomposite Revealed by Micro-Raman Imaging and Its Influence on Water Permeability of a Film.

Substantial adsorption of water vapor triggered by hydrogen-bonding interactions between water molecules and cellulose chains (or nanoplates) is hard to avoid in nanocomposite films, although the addition of nanoplates can improve the oxygen (or carbon dioxide) barrier property. In the present work, an effective strategy is raised to decline adsorption by weakening hydrogen-bonding interactions via chemical cross-linking by epichlorohydrin (ECH) without sacrificing the homogeneous dispersion of nanoplates. The generated microdomain structure of the chemical cross-linking reaction via ECH is explicitly revealed by micro-Raman imaging. Unambiguously, Raman maps of scanning elucidate the distribution and morphology of physical and chemical cross-linking domains quantitatively. The chemical cross-linking domains are nearly uniformly located in the matrix at a low degree of cross-linking, while the interconnected and assembled networks are formed at a high degree of cross-linking. ECH boosts the formation of chemical cross-linking microdomains, bringing out the terrific water vapor barrier property and alleviating the interfacial interactions in penetration, consequently magnifying the water contact angle and holding back the water vapor permeability. Our methodology confers an effective and convenient strategy to obtain remarkable water vapor-resistant cellulose-based films that meet the practical application in the packaging fields.

A two-stage system coupling hydrolytic acidification with algal microcosms for treatment of wastewater from the manufacture of acrylonitrile butadiene styrene (ABS) resin.

OBJECTIVES: To demonstrate the effectiveness of a novel two-stage system coupling hydrolytic acidification with algal microcosms for the treatment of acrylonitrile butadiene styrene (ABS) resin-manufacturing wastewater. RESULTS: After hydrolytic acidification, the BOD5/COD ratio increased from 0.22 to 0.56, showing improved biodegradability of the wastewater. Coupled with hydrolytic acidification, the algal microcosms showed excellent capability of in-depth removal of COD, NH3-N and phosphorus with removal rates 83, 100, and 89%, respectively, and aromatic pollutants, including benzene, were almost completely removed. The biomass concentration of Chlorella sp. increased from 5 × 106 to 2.1 × 107 cells/ml after wastewater treatment. CONCLUSIONS: This two-stage coupling system achieved deep cleaning of the benzene-containing petrochemical wastewater while producing greater algae biomass resources at low cost.

Application of HIF-1α by gene therapy enhances angiogenesis and osteogenesis in alveolar bone defect regeneration.

BACKGROUND: A successful clinical outcome for implanted tissue-engineered bone is dependent on the establishment of a functional vascular network. Gene-enhanced tissue engineering represents a promising approach for vascularization and osteogenesis. In the present study, we tested the angiogenesis and osteogenesis efficacy of gelatin as the scaffold carrier in combination with a virus encoding the HIF-1α gene in a rat alveolar bone defect model. METHODS: Three groups of 10 rats each were either left untreated, treated with adenovirus encoding hypoxia-inducible factor-1α (AdHIF-1α)/gelatin sponge or treated with gelatin sponge with adenovirus encoding red fluorescence protein, respectively. At 4 weeks, all samples were determined by micro-computed tomography, histological analyses and immunohistochemical studies. RESULTS: Scaffolds loaded with AdHIF-1α were able to sustain the release of AdHIF-1α for up to 21 days and alveolar bone defects treated with scaffolds containing AdHIF-1α significantly induced new bone and new vessel formation in vivo. CONCLUSIONS: Overexpression of HIF-1α by gene therapy may be a useful method for enhancing alveolar bone defect osteogenesis and angiogenesis. Copyright © 2016 John Wiley & Sons, Ltd.

[Study on interface compatibility and fracture resistance of polyglycidyl methacrylate pre-impregnated quartz fiber reinforced polymethyl methacrylate denture base resin].

OBJECTIVE: To explore the reinforcement of polyglycidyl methacrylate (PGMA) pre-impregnated quartz fiber mesh in denture base materials by investigation of interface compatibility and fracture resistance. METHODS: 1-layer, 2-layer, 3-layer PGMA pre-impregnated quartz fiber meshes, electrolyzed cobalt-chromium alloy mesh and cobalt-chromium alloy mesh conditioned by metal primer were integrated in polymethyl methacrylate (PMMA) resin by sandwich embedding method. Block samples of 5 groups were prepared (40 mm×15 mm×2 mm). Fracture resistance was determined in a 3-point bending test at 2 mm/min. Scanning electron microscope (SEM), micrographs were taken from the fractured surfaces to analyze the bonding interface compatibility. RESULTS: The group of 3-layer PGMA pre-impregnated quartz fiber mesh presented the highest elastic modulus of 6 406 MPa and flexural strength of 227 MPa among the five groups, while the 1-layer and 2-layer expressed the similar elastic modulus and flexural strength to the pure PMMA group. The metal groups demonstrated better mechanical properties, while the metal surface conditioner played much better. The metal surface conditioner pre-impregnated cobalt-chromium alloy and PGMA pre-impregnated quartz fiber mesh showed compatible interface with PMMA. CONCLUSION: The mechanical properties were improved by the increasing of the fiber by adding the more meshed. Although the benign interface did help the compatibility, the quantity of the fibers played an important role in the strength.

Highly efficient near-infrared emission in Er3+ doped silica films containing size-tunable SnO2 nanocrystals.

Co-doping size-tunable SnO2 nanocrystals into Er(3+) ions embedded silica thin films produces an enhancement of Er-related near-infrared emission by three orders of magnitude. Selective PL and PLE measurements show that energy transfer process occurs between SnO2 nanocrystals and Er(3+) ions. Quantitative studies of PL decay lifetime and photoluminescence temperature-dependence demonstrate that both high energy transfer efficiency from SnO2 nanocrystals to Er(3+) ions and the partial incorporation of Er(3+) ions into SnO2 nanocrystals contribute to the near-infrared emission enhancement. All these results indicated that SnO2 nanocrystals with suitable size have great potentials in fabricating high-efficiency near-infrared luminous materials as sensitizers of Er(3+) ions.

The effect of Ti anodized nano-foveolae structure on preosteoblast growth and osteogenic gene expression.

The TiO2 nanotubes by anodization have been extensively studied for medical implant and orthopedic applications because of enhancing bone development. In the present study, a new nano-foveolae structure verified by SEM and AFM was prepared by simulating the nanotubes exfoliation from anodized Ti. MC3T3-E1 preosteoblasts were used to investigate the effects of new nanoscale surface on cell spreading, proliferation, and osteogenic gene expression. The new nano-foveolae structure supported preosteoblast better spreading, more filopodiaes shown by SEM (4 h), and lower proliferation (72 h) than the smooth Ti. By two weeks, the new nanoscale surface induced higher expression of osteogenic markers alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN), and collagen I (COL I) with real-time RT-PCR compared to the control group. The results of this study suggest that the new nano-foveolae structure provides a favorable surface for functions of bone cells.

Scientific mapping of hotspots and trends of post and core research based on the Web of Science: A bibliometric analysis.

Statement of problem: Post and core (PC) restoration has been widely used to restore endodontically treated teeth. Nevertheless, bibliometric studies focusing on PC research are lacking. Purpose: The purpose of this bibliometric analysis was to review the general situation and determine the research direction of PC restoration by means of visualization, including the time development, countries, institutions, authors, journals, research categories, and the information of references with the strongest citation burst. Material and methods: The search was carried out within the topic field of the Web of Science (WoS) database. CiteSpace, VOSviewer, and R language were used to analyze the literature. Bibliometric indicators in terms of title, keyword, reference, publication time, institution, country and citation information were analyzed. Results: Between 1966 and 2022, dental research on PC trended upward, especially in 2011 and up to 2022. Scholars in Brazil, the United States, and Italy actively participated in PC research. The country that published the most was Brazil. Italy both ranked first in the H-index and average citations per item and had cooperative relations with several countries. The United States ranked first in the world in total citation count. The University of Siena published the most articles. The Journal of Prosthetic Dentistry (JPD) was the major contributing journal. The top three authors in this field were Ferrari M, Goracci C and Naumann M. The largest cooperative network of authors consisted of four Italian scholars. There were six main clusters of research topics on PC through CiteSpace co-citations. In addition, CiteSpace co-citations, CiteSpace Burst detection and VOSviewer keyword analysis showed the most important research interests, such as bond strength, fiber post, fracture resistance, and finite element analysis. Photodynamic therapy is the latest research hotspot. Finally, there were the top 25 references with the strongest citation bursts, which mainly focused on four aspects, namely, studies related to fiber posts, PC bonding strength, finite element analysis, and residual teeth and the ferrule effect. Conclusions: This bibliometric analysis provides a comprehensive overview of PC research, including the research time, country, institution, author, journal, article clustering, article keywords, and important literature analysis, so that researchers can have a clear understanding of the research situation in this field.

Effect of radiation cross-linked collagen scaffold in alveolar ridge preservation of extraction socket.

This study aimed to evaluate the properties of radiation cross-linked collagen scaffold (RCS) and its efficacy for alveolar ridge preservation (ARP). RCS was prepared from collagen dispersion by electron beam irradiation and freeze-drying. The microstructure, swelling ratio, area alteration and mechanical properties of RCS were characterized. Fifty-four New Zealand rabbits performing incisor extraction on maxilla and mandible were randomly assigned into positive, sham operation or treatment groups. Micro-computed tomography (micro-CT) scans, performed after 1, 4, and 12 weeks of surgery, were to assess changes in ridge height at buccal and palatal side, in ridge width and in micromorphological parameters. Histological analysis accessed socket microarchitecture. The results showed that RCS had stable mechanical properties and morphologic features that provided a reliable physical support for ARP. Dimensional changes in treatment group revealed significantly greater vertical height at buccal (5.32 [3.37, 7.26] mm, p < .0001) and palatal (4.37 [2.66, 6.09] mm, p < .0001) side, and horizontal width at the maxilla (0.16 [0.04, 0.28] mm, p < .01) and mandible (0.33 [0.11, 0.54] mm, p < .01) than those in sham operation group after 12 weeks. The treatment group had advantage than positive group in vertical height preservation, quantitatively. The order and density of bone trabeculae were improved in treatment group. These findings indicated that RCS had the potential to serve as an effective scaffold for ARP.