[Finite element analysis and biomimetic optimal design of full-crown restoration].

Objective: To improve the mechanical properties of full-crown restorations and illuminate the optimal elastic modulus distribution through bionic optimization design and finite element analysis (FEA). Methods: Seven 3D models of mandibular first premolars with different full-crown restorations were constructed: (A) zirconia monolithic crown, (B) lithium disilicate monolithic crown, (C) zirconia bilayer crown, (D) lithium disilicate bilayer crown, (E) 8-layer crown referred to the elastic modulus distribution of human enamel, (F) and (G) were 8-layer crowns with elastic modulus distribution calculated by a genetic algorithm (GA) to minimize the tensile stresses in the crown and the shear stresses at the cementing line, respectively. Results in the crowns and cementing lines were obtained with maximum principal stress after applying a static load of 600 N. Results: The principal tensile stresses in the full-crown restorations were mainly concentrated in the cervical margins and the crown-cementing interface. Among them, G exhibited a peak tensile stress of 25.79 MPa, which decreased to 17.72 MPa in E and 16.25 MPa in F; The principal shear stresses in cementing lines were concentrated along the margins and low on the axial wall. The peak shear stress of the cementing line of E and F was 11.81 MPa and 11.79 MPa, respectively. While G was found to has the lowest peak shear stress of 6.14 MPa. Conclusion: The elastic modulus distribution optimized by GA to reduce the peak shear stress of the cementing line can better improve the mechanical properties of the full-crown restoration.

Physicochemical properties and cytotoxicity of an experimental resin-based pulp capping material containing the quaternary ammonium salt and Portland cement.

AIM: To evaluate in vitro the physicochemical properties, cytotoxicity and calcium phosphate nucleation of an experimental light-curable pulp capping material composed of a resin with antibacterial monomer (MAE-DB) and Portland cement (PC). METHODOLOGY: The experimental material was prepared by mixing PC with a resin containing MAE-DB at a 2 : 1 ratio. Cured pure resin containing MAE-DB served as control resin. ProRoot MTA and Dycal served as commercial controls. The depth of cure, degree of monomer conversion, water absorption and solubility of dry samples, calcium release, alkalinizing activity, calcium phosphate nucleation and the cytotoxicity of materials were evaluated. Statistical analysis was carried out using anova followed by Tukey's HSD test (equal variance assumed) or Tamhane test (equal variance not assumed) and independent-samples t-tests. RESULTS: The experimental material had a cure depth of 1.19 mm, and the mean degree of monomer conversion was 70.93% immediately post-cure and 88.75% at 24 h post-cure. The water absorption of the experimental material was between those of MTA and Dycal, and its solubility was significantly less (P < 0.05) than that of Dycal and higher than that of MTA. The experimental material exhibited continuous calcium release and an alkalinizing power between those of MTA and Dycal throughout the test period. Freshly set experimental material, control resin and all 24-h set materials had acceptable cytotoxicity. The experimental material, MTA and Dycal all exhibited the formation of apatite precipitates after immersion in phosphate-buffered saline. CONCLUSIONS: The experimental material possessed adequate physicochemical properties, low cytotoxicity and good calcium phosphate nucleation.

Risk of infective endocarditis in patients with systemic lupus erythematosus in Taiwan: a nationwide population-based study.

Objectives Patients with systemic lupus erythematosus are considered vulnerable to infective endocarditis and prophylactic antibiotics are recommended before an invasive dental procedure. However, the evidence is insufficient. This nationwide population-based study evaluated the risk and related factors of infective endocarditis in systemic lupus erythematosus. Methods We identified 12,102 systemic lupus erythematosus patients from the National Health Insurance research-oriented database, and compared the incidence rate of infective endocarditis with that among 48,408 non-systemic lupus erythematosus controls. A Cox multivariable proportional hazards model was employed to evaluate the risk of infective endocarditis in the systemic lupus erythematosus cohort. Results After a mean follow-up of more than six years, the systemic lupus erythematosus cohort had a significantly higher incidence rate of infective endocarditis (42.58 vs 4.32 per 100,000 person-years, incidence rate ratio = 9.86, p < 0.001) than that of the control cohort. By contrast, the older systemic lupus erythematosus cohort had lower risk (adjusted hazard ratio 11.64) than that of the younger-than-60-years systemic lupus erythematosus cohort (adjusted hazard ratio 15.82). Cox multivariate proportional hazards analysis revealed heart disease (hazard ratio = 5.71, p < 0.001), chronic kidney disease (hazard ratio = 2.98, p = 0.034), receiving a dental procedure within 30 days (hazard ratio = 36.80, p < 0.001), and intravenous steroid therapy within 30 days (hazard ratio = 39.59, p < 0.001) were independent risk factors for infective endocarditis in systemic lupus erythematosus patients. Conclusions A higher risk of infective endocarditis was observed in systemic lupus erythematosus patients. Risk factors for infective endocarditis in the systemic lupus erythematosus cohort included heart disease, chronic kidney disease, steroid pulse therapy within 30 days, and a recent invasive dental procedure within 30 days.

High-Performance Dental Resins Containing a Starburst Monomer.

Dimethacrylate-based chemistries feature extensively as resin monomers in dental resin-based materials due to their distinguished overall performance. However, challenges endure, encompassing inadequate mechanical attributes, volumetric shrinkage, and estrogenicity. Herein, we first synthesized a novel resin monomer, 9-armed starburst polyurethane acrylate (NPUA), via the grafting-onto approach. Compared to the primary commercial dental monomer 2,2-bis [p-(2'-hydroxy-3'-methacryloxypropoxy) phenyl] propane (Bis-GMA) (with a viscosity of 1,174 ± 3 Pa·s and volumetric shrinkage of 4.7% ± 0.1%), the NPUA monomer achieves the lower viscosity (158 ± 1 Pa·s), volumetric shrinkage (2.5% ± 0.1%), and cytotoxicity (P < 0.05). The NPUA-based resins exhibit the higher flexural strength, flexural modulus, hardness, and hydrophobicity and lower volumetric shrinkage, water absorption, and solubility compared to the Bis-GMA (70 wt%)/TEGDMA (30 wt%) resins. The NPUA-based composites exhibit significantly higher flexural strength, flexural modulus, and hardness and lower volumetric shrinkage (171.4 ± 3.0 MPa, 12.6 ± 0.5 GPa, 2.0 ± 0.2 GPa, and 3.4% ± 0.2%, respectively) compared to the Bis-GMA group (120.3 ± 4.7 MPa, 9.4 ± 0.7 GPa, 1.5 ± 0.1 GPa, and 4.7% ± 0.2%, respectively; P < 0.05). This work presents a viable avenue for augmenting the physicochemical attributes of dental resins.

Phosphoric acid-etching promotes bond strength and formation of acid-base resistant zone on enamel.

This study examined the effect of phosphoric acid (PA) etching on the bond strength and acid-base resistant zone (ABRZ) formation of a two-step self-etching adhesive (SEA) system to enamel. An etch-and-rinse adhesive (EAR) system Single Bond (SB) and a two-step SEA system Clearfil SE Bond (SE) were used. Human teeth were randomly divided into four groups according to different adhesive treatments: 1) SB; 2) SE; 3) 35% PA etching→SE primer→SE adhesive (PA/SEp+a); (4) 35% PA etching→SE adhesive (PA/SEa). Microshear bond strength to enamel was measured and then statistically analyzed using one-way analysis of variance and the Tukey honestly significant difference test. The failure mode was recorded and analyzed by χ( 2 ) test. The etching pattern of the enamel surface was observed with scanning electron microscope (SEM). The bonded interface was exposed to a demineralizing solution (pH=4.5) for 4.5 hours and then 5% sodium hypochlorite with ultrasonication for 30 minutes. After argon-ion etching, the interfacial ultrastructure was observed using SEM. The microshear bond strength to enamel of the SE group was significantly lower (p<0.05) than that of the three PA-etched groups, although the latter three were not significantly different from one another. The ABRZ was detected in all the groups. In morphological observation, the ABRZ in the three PA-etched groups were obviously thicker compared with the SE group with an irregular wave-shaped edge.

Enhanced Bonding to Caries-Affected Dentin Using an Isocyanate-Based Primer.

Dental caries is the most common oral disease and the most common cause of resin restorations. In minimally invasive dentistry, the principle behind cavity preparation is to remove external caries-infected dentin (CID) and preserve internal caries-affected dentin (CAD) and sound dentin (SD). The cavity floor is mainly composed of CAD, but the poor bonding performance of CAD has become a widespread concern. This study evaluated the performance of a new collagen-reactive monomer (ITCM) used as a primer to improve the bonding performance of CAD. The experimental specimens were grouped as follows: SD, CAD, and ITCM-pretreated CAD (CAD-ITCM). Dentin slices were obtained for attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis. The bonded samples were subjected to microtensile bond strength analysis after 24 h of water storage or aging by thermocycling, and the bonding interface quality was evaluated by nanoleakage assessment, interfacial nanoindentation testing, and in situ zymography. Cytotoxicity experiments with ITCM were performed. ATR-FTIR showed that the isocyanate groups in ITCM can covalently bind and form hydrogen bonds with the collagen in CAD to mediate chemical bonding. ITCM pretreatment significantly improved the bond strength of CAD (P < 0.05), reduced interfacial nanoleakage, improved the sealing of the bonding interface, enhanced the homogeneity of the hybrid layer, and inhibited matrix metalloproteinase activity. In addition, ITCM presented acceptable biocompatibility for dental restorative application. Taken together, this study reported the application of ITCM to induce collagen-based chemical bonding in the CAD bonding system, which fills the gap in strategies to improve the bonding performance of CAD immediately and after aging and has important clinical application prospects.

Explore comorbidities associated with systemic lupus erythematosus: a total population-based case-control study.

BACKGROUND: Because of the increasing incidence and overall burden of systemic lupus erythematosus (SLE), efforts have been made to identify the factors that contribute to SLE onset and progression. AIM: We conducted a total population-based case-control study to explore the prior comorbidities associated with SLE. DESIGN AND METHODS: Data were collected from Taiwan's National Health Insurance Research Database. Newly diagnosed SLE patients from 1 January 2010, to 31 December 2013 (n = 2847), were exactly matched at a 1:4 ratio for gender, age, residence and insurance premium to form a non-SLE group. Multivariate conditional logistic regression with stepwise selection was used to find the prior-associated comorbidities. RESULTS: A total of 38 prior comorbidities were associated with SLE incidence (32 positive and 6 negative associations). Positively associated comorbidities could be categorized as autoimmune-related inflammation of multiple organs including skin, blood, liver, tooth, thyroid, musculoskeletal and connective tissue. Among them, diffuse diseases of connective tissue (International Classification of Disease, Ninth Revision, Clinical Modification 710) exhibited the most robust association (OR = 5.68, 95% CI = 4.02-8.03, P < 0.001) in the 5 years before the index date. Negatively associated comorbidities could be attributed to diabetes mellitus and pregnancy related symptoms. CONCLUSIONS: Our results supported that increased awareness of SLE may be warranted for patients with autoimmune-related comorbidities of multiple organs. However, diabetes mellitus and pregnancy related symptoms were negatively associated with SLE incidence in this study. Further studies are warranted to elucidate the possible underlying mechanism and for better understanding the pathogenesis of SLE.

Location of MMPs in human radicular dentin and the effects of MMPs inhibitor on the bonding stability of fiber posts to radicular dentin.

This study explored the location of MMP-2, -3, -8 in human root dentin and the inhibition of EGCG/EGCG-3Me on dentin-originated collagen proteases activities. Also, the study evaluated EGCG/EGCG-3Me modified etch-and-rinse adhesives (Single Bond 2, SB 2) for their bonding stabilities to intraradicular dentin. Immunostaining and liquid chip analysis demonstrated that MMP-2 and MMP-8 are widely distributed in root dentin while MMP-3 shows a higher fluorescence intensity in the middle and apical third of the root. The contents of MMP-2, -3 and -8 varies in different locations of human tooth root and MMP-2 has the highest content than MMP-3 and MMP-8 at each third of teeth root. Both EGCG and EGCG-3Me showed an inhibitory effect on the root dentin-derived MMPs in a concentration dependent manner (P < 0.05) and the inhibitory activity of EGCG-3ME was stronger than that of EGCG at the same concentration (P < 0.05). EGCG and EGCG-3Me were incorporated separately into the adhesive SB 2 at concentrations of 200, and 400 µg/mL respectively. The immediate push-out strength of SB 2 was not compromised by EGCG/EGCG-3Me modification. EGCG/EGCG-3Me modified adhesive had higher push-out strength than SB 2 after thermocycling, showing no correlation with concentration.

Selection of the distraction implant length with improved biomechanical properties by three-dimensional finite element analysis.

In this study, the distraction length of distraction implant was set as input variable which ranged from 2 to 10 mm. The effect of distraction length on the maximum Von Mises stress in the jaw bones and the implant were evaluated by a finite element method. The results showed that under axial load, the maximum equivalent stresses in cortical bone, cancellous bone, and distraction screw decreased by 5·8%, 8·6%, and 11·0%, respectively, with the changing of distraction length, and under buccolingual load those decreased by 0·3%, 18·0%, and 13·0%, respectively. The data indicate that cancellous bone is more sensitive to distraction length than the cortical bone. Under both loads, the central distraction screw was subjected to the stress concentration and more easily damaged by buccolingual force than by axial force. Distraction implant with distraction length exceeding 8 mm showed relatively better biomechanical behaviour.

[Prospective clinical study on the influence of implant crown and bridge prostheses characteristics on peri-implant disease].

Objective: To investigate the influence of different characteristics of implant-supported fixed dental prostheses on the incidence of peri-implant disease. Methods: Prospective cohort was established for patients who received implant-supported fixed dental prostheses at the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University between June 2014 and September 2015. Several patient-related factors, implant prostheses factors, and oral hygiene maintenance factors were collected. The Log-rank test was used to compare the peri-implant disease rates of various factors, and the Cox proportional hazards model was used to conduct multivariate study on single factor significant factors to analyze the impact on the incidence of peri-implant disease. Results: A total of 214 subjects and 351 implants were included in the cohort, the follow-up period was (11.0±3.5) months. Finally, 43.0% (92/214) of patients and 37.3% (131/351) of implants developed peri-implant diseases. The incidence of peri-implant mucositis and peri-implantitis was 41.1% (88/214) and 4.2% (9/214) at the subject level,and 34.2% (120/351) and 3.1% (11/351) at the implant level. Among the factors associated with the implant prosthesis, single factor Log-rank analysis showed that prostheses retention methods, proximal contact of the prostheses, occlusion situation were statistical significance (P<0.05). Multivariate analysis using Cox proportional hazards model showed that screw retention (hazard ratio=2.38, 95%CI: 1.42-3.99), proximal contact loss of the prostheses (hazard ratio=2.36, 95%CI: 1.31-4.27) were independent risk factors for peri-implant disease (P<0.05). Conclusions: Factors such as prostheses retention mode and proximal contact characteristics have important influence on the health status of the implant.

[Advances in color stability of resin cements and its influence on all-ceramics restorations].

Resin cements have been widely employed for bonding all-ceramic restorations in clinical practice, its color stability is directly related to long-term prosthetic effect of restorations. Discoloration of resin cements can be attributed to two causes: endogenous factors are generally related to material compositions and initiation mechanism of polymerization; exogenous factors are mainly related to stimulation of local oral environment. Color stability of resin cements has close relationship with esthetic effect of all-ceramic restorations. The aim of this literature review was to make a presentation and discussion systematically about color stability of resin cements commonly used clinically, its influence factors and influence on all-ceramic restorations, so as to provide a reference for the application of all-ceramic restorations.

The antibacterial effect and physical performance of pit and fissure sealants based on an antibacterial core-shell nanocomposite.

The application of pit and fissure sealants is a well-established method to prevent and treat early childhood caries. Resin-based sealants with antibacterial properties provide additional benefits for caries prevention in a cariogenic oral environment. The objective of this study was to evaluate the effect of an antibacterial core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) on the properties of a resin-based pit and fissure sealant. A commercialized pit and fissure sealant without fluoride, Concise (3M, ESPE, USA), was used as the parent material and negative control. Experimental antibacterial sealants were formulated by the addition of AgBr/BHPVP nanoparticles at mass fractions of 0.5, 1.0, and 1.5 wt% to the parent material. A fluoride-releasing sealant, Clinpro (3M, ESPE), was used as the positive control. Bacterial colony-forming unit (CFU) counts, metabolic activity tests, field emission-scanning electron microscopy (FE-SEM), and confocal laser scanning microscopy (CLSM) observations were used to evaluate the antibacterial properties of AgBr/BHPVP-modified sealants against Streptococcus mutans before and after five months of aging. The Vickers microhardness, degree of conversion, and microleakage level of the sealants were also investigated. According to the results of CFU counts and metabolic tests, sealants containing AgBr/BHPVP showed better contact-killing bactericidal activity against S. mutans than the two commercial sealants, irrespective of aging conditions (both P < 0.05). The AgBr/BHPVP-modified sealants also showed a significant inhibitory effect on the planktonic S. mutans around the cured sealant surfaces. In addition, the Vickers microhardness, degree of conversion, and microleakage level of the parent material were not damaged by modification with AgBr/BHPVP (P > 0.05). AgBr/BHPVP-modified pit and fissure sealant with a dual bactericidal mechanism is a promising option for the prevention of pit and fissure caries.

A novel dentin bonding scheme based on extrafibrillar demineralization combined with covalent adhesion using a dry-bonding technique.

Dentin bonding is a dynamic process that involves the penetration of adhesive resin monomers into the extrafibrillar and intrafibrillar demineralized collagen matrix using a wet-bonding technique. However, adhesive resin monomers lack the capacity to infiltrate the intrafibrillar space, and the excess water that is introduced by the wet-bonding technique remains at the bonding interface. This imperfectly bonded interface is inclined to hydrolytic degradation, severely jeopardizing the longevity of bonded clinical restorations. The present study introduces a dentin bonding scheme based on a dry-bonding technique, combined with the use of extrafibrillar demineralization and a collagen-reactive monomer (CRM)-based adhesive (CBA). Selective extrafibrillar demineralization was achieved using 1-wt% high-molecular weight (MW) carboxymethyl chitosan (CMCS) within a clinically acceptable timeframe to create a less aggressive bonding substance for dentin bonding due to its selectively extrafibrillar demineralization capacity. CMCS demineralization decreased the activation of in situ collagenase, improved the shrinking resistance of demineralized collagen, and thus provided stronger and more durable bonding than traditional phosphoric acid etching. The new dentin bonding scheme that contained CMCS and CBA and used a dry-bonding technique achieved an encouraging dentin bonding strength and durability with low technical sensitivity. This bonding scheme can be used to improve the stability of the resin-dentin interface and foster the longevity of bonded clinical restorations.

Bifunctional conjugates comprising ß-cyclodextrin, polyethylenimine, and 5-fluoro-2'- deoxyuridine for drug delivery and gene transfer.

Earlier reports indicated that the conjugates (PEI(600)-CD, PC) of ß-cyclodextrin and low-molecular-weight polyethylenimine (PEI, M(w) 600) can be used as efficient gene carriers in glioma cancer therapy. Incorporating anticancer drugs onto PC conjugates may endow them with new and interesting properties for great applications. In this work, FU-PEI(600)-CD (FPC) conjugates comprising PC and 5-fluoro-2'-deoxyuridine (FdUrd) were prepared as new bifunctional anticancer prodrugs with improved therapeutic effects, as well as good gene transfer efficiency. In comparison with free FdUrd, FPC could inhibit proliferation and enhance cytotoxicity on glioma cells. The results of hematoxylin and eosin (HE) staining indicated that C6 cells treated with FPC shrunk more seriously. Unlike FdUrd, cell cycle analysis indicated that C6 cells were primarily arrested in the G1 phase in the presence of FPC. Cellular uptake of FPC in C6 cells was about 10 times higher than that of FdUrd. In addition, the in vitro and in vivo gene transfection indicated that FPC still exhibited good gene expression efficiency. With the ability to deliver drugs and transfer genes, such bifunctional FPC conjugates may have great potential applications in combination therapy of cancers.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases.

OBJECTIVE: Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients. MATERIALS AND METHODS: In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters. RESULTS: Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs. CONCLUSIONS: This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

Isocyanate-terminated urethane-based methacrylate for in situ collagen scaffold modification.

When damaged or fractured collagen-rich hard tissues are repaired by resin material, the collagen matrix may be used as a scaffold, after removal of the natural minerals, for resin monomers to penetrate and polymerize in-situ. Formation of a collagen-polymer hybrid biocomposite via mechanical hybridization provides a stable and strong link between endogenous tissue and the prosthesis for successful clinical integration. However, the heterogeneity between hydrophobic resin polymers and hydrophilic collagen presents a challenge to the quality of hybrid biocomposite. The objective of the present study was to evaluate the potential benefits of a collagen-reactive monomer (CRM, an isocyanate-terminated urethane-based methacrylate) with covalent affinity to collagen as "chemical link" to enhance in-situ resin hybridization within a collagen scaffold. Here, the CRM ligand with active isocyanate group may be chemically grafted onto the collagen receptor via covalent and hydrogen bonds. Dentin-derived collagen chemical modified by CRM shows improved mechanical property, thermostability and enzymatic stability. Moreover, CRM inhibited both exogenous and endogenous collagenase activities. The modification of collagen by chemical grafting of resin monomers improved its mechanical and physicochemical properties and demonstrated the potential of CRM for use in promoting chemical adhesion and creating a much stronger and durable bonding interface. Formation of a chemical bond between polymer and collagen scaffold in-situ improves the mechanical performance of collagen and may create a much stronger and durable collagen-polymer hybrid material. Addition of CRM into adhesives might effectively prolong the longevity of clinical resin-bonded restorations.

Evaluation of a Collagen-Reactive Monomer with Advanced Bonding Durability.

This study evaluated the use of a new collagen-reactive monomer (CRM), isocyanate-terminated urethane methacrylate precursor, which has covalent affinity to dental collagen, in the formation of dentin-resin bonds and compared it with 2 other dental adhesives. Dentin specimens were bonded with either the CRM-based adhesive (CBA), One-Step (OS; Bisco, Inc.), or a negative adhesive (NA) control and subjected to 24-h storage in water, thermocycling to simulate 1-y clinical function, or a matrix metalloproteinase-mediated aging process. We tested the microtensile bond strength (µTBS), characterized the bonding interface with an atomic force microscope, conducted micro-Raman analysis, and performed leakage tests and in situ zymography. CBA and OS exhibited comparable bonding strength after 24 h (P > 0.05); however, there was a sharp decrease in µTBS after aging for all except CBA (P < 0.001). Raman spectra results indicated increased collagen crosslinking and chemical reaction between the adhesive and collagen in the CBA group. CBA achieved high-quality hybridization with collagen, improving mechanical properties and integrity, and decreased the enzyme-mediated degradation of the bonding interface by inhibiting collagenolytic activity. With the promising bonding durability of coapplied CBA, CRM may be the first dental adhesive to provide strong and long-lasting resin-dental collagen bonding without the additional conditioning step. The use of CBA results in high-quality hybrid layers that protect the resin-dentin interface from harmful biological and chemical activities commonly occurring in the oral environment.

Pegylated interferon alpha-2a versus standard interferon alpha-2a for treatment-naive dialysis patients with chronic hepatitis C: a randomised study.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is prevalent in dialysis patients, and standard interferon monotherapy is the current standard of care for such patients. AIM: To investigate whether pegylated interferon has a better therapeutic efficacy and safety profile than standard interferon in dialysis patients with chronic hepatitis C. METHODS: 50 such patients were randomly assigned to receive either pegylated interferon alpha-2a 135 microg subcutaneously once per week or standard interferon alpha-2a 3 million units subcutaneously thrice per week for 24 weeks. The primary efficacy and safety end points were sustained virological response (SVR) by intention-to-treat analysis and treatment-related withdrawal rate during the study. RESULTS: In univariate analysis, patients receiving pegylated interferon alpha-2a tended to have a higher sustained virological response (SVR) than those receiving standard interferon alpha-2a (48% vs 20%, p = 0.07). By using multivariate analysis, treatment with pegylated interferon alpha-2a (p = 0.02) and pretreatment HCV RNA level <800 000 IU/ml (p = 0.007) were independently predictive of an SVR. All patients failing to achieve a rapid virological response (RVR) could not achieve an SVR. In addition, patients receiving pegylated interferon alpha-2a had a significantly lower treatment-related withdrawal rate than those receiving standard interferon alpha-2a (0% vs 20%, p = 0.04). CONCLUSIONS: Pegylated interferon alpha-2a once weekly provides more effective and safer therapy than standard interferon alpha-2a thrice weekly for treatment-naive dialysis patients with chronic hepatitis C.

[Review on the etiology and complications of hand, foot and mouth disease, using data from the national sentinel surveillance program, in China, 2015-2016].

Objective: To understand the characteristics relating to the etiology and complications of hand, foot and mouth disease (HFMD) based on data from the pilot National Sentinel Surveillance (NSS) program so as to explore the feasibility, advantages and disadvantages of the NSS. Methods: Data were extracted from the NSS system, conducted in 11 provinces of China from November 2015 to October 2016. Characteristics regarding the etiology, complications of HFMD and factors related to the positive rates of HFMD specimens were analyzed under the logistic regression method by SPSS 20.0 software. Results: A total of 4 783 specimens were collected, including 3 390 from mild, 1 390 from severe and 3 from death cases. The overall positive rate was 81.43% (3 895/4 783). Other enteroviruses (non EV71/Cox A16 enteroviruses) appeared the major serotype (52.68%, 1 482/2 813) for mild infection of the disease while EV71 was for the severe cases (65.31%, 706/1 081). The serotype spectrum revealed by the pilot NSS was almost identical with the existing surveillance system. Other enteroviruses tended to infect younger children (χ(2)=130.17, P<0.001) than EV71 and Cox A16, in China. The multivariate logistic regression results showed that higher positive rate was associated with specimens which were collected from males, at children' hospitals, in peak seasons, timely and in stools. The positive rates presented downwarding trends with the extension of the onset-sampling interval (χ(2)=14.47, P<0.001 in stool specimen; χ(2)=31.99, P<0.001 in throat swab; χ(2)=24.26, P<0.001 in anal swab). Aseptic meningitis, non-brainstem encephalitis and brainstem encephalitis appeared the top three complications of both EV71-associated and other enteroviruses-associated severe HFMD cases. Conclusions: Factors as gender, season/place/timeliness of specimen collection, and types of hospital all appeared independently influenced the positive rates. NSS seemed feasible to be used as an alternative or supplement tool to the existing surveillance program in China.

[Effect of dentin proteoglycans on the stability of resin-dentin bonds against artificial saliva storage].

Objective: To investigate the potential effect of proteoglycans (PG) and glycosaminoglycans (GAG) on the stability of resin-dentin bonds against artificial saliva storage. Methods: Seventy-two extracted molars were used to obtain standard dentin bonding surface, and the specimens were etched for 15 s with 37% phosphoric acid and divided into three groups using a table of random number. Then the three groups undergone different incubating procedures as follow: specimens in chondroitinase ABC (C-ABC) group were incubated with C-ABC, specimens in trypsin (TRY) group were incubated with trypsin, and specimens in the control group were incubated with deionized water. All specimens were incubated at 37 ℃ for 48 h in the oscillators. Then specimens in each group were randomly assigned into three subgroups (n=8) as follows: immediate control subgroup, aging subgroups with artificial saliva storage for 6 months and 12 months. Microtensile bond strength (µTBS), fracture mode, bonding interface morphology and nanoleakage were evaluated. Results: Immediately and with artificial saliva storage for 6 months and 12 mouths, the µTBS of TRY group ([49.04±3.57], [37.01±3.21] and [35.27±3.56] MPa) were significantly higher than those in the control group ([40.71±3.32], [28.87±2.34] and [24.20±2.07] MPa) (P<0.05). The immediate µTBS of C-ABC group ([32.94±2.45] MPa) was significantly lower than that of the control group (P<0.05). While with artificial saliva storage for 6 months and 12 mouths, the µTBS of C-ABC group ([26.46±2.45] and [22.50±2.58] MPa) were no differences with those of the control group (P>0.05). The ratio of cohesive fracture increased with the extension of aging time. Some narrow gaps were found in hybrid layer of the control group with artificial saliva storage for 6 months and 12 mouths. Conclusions: Removal of PG increased the µTBS and durable bonds to dentin, while removal of GAG decreased the µTBS, however, it can be of help to create more durable bonds to dentin.