Journal of Applied Biomaterials & Functional Materials最新文献

Background: To maintain and enhance the wound healing effects of mesenchymal stem cells (MSCs), a scaffold for hosting MSCs is needed, which ought to be completely biocompatible, durable, producible, and of human source.

Objective: To build a cell-extracellular matrix (ECM) complex assembled by human umbilical cord mesenchymal stem cells (HuMSCs) and to investigate its clinical potentials in promoting wound healing.

Method: HuMSCs were isolated and expanded. When the cells of third passage reached confluency, ascorbic acid was added to stimulate the cells to deposit ECM where the cells grew in. Four weeks later, a cells-loaded ECM sheet was formed. The cell-ECM complex was observed under the scanning electron microscopy (SEM) and subjected to histological studies. The supernatants were collected and the cell-ECM complex was harvested at different time points and processed for enzyme-linked immune sorbent assay (ELISA) and mRNA analysis. The in vivo experiments were performed by means of implanting the cell-ECM complex on the mice back for up to 6 months and the specimens were collected for histological studies.

Results: After 4 weeks of cultivation with ascorbic stimulation, a sheet was formed which is mainly composed with HuMSCs, collagen and hyaluronic acid. The cell-ECM complex can sustain to certain tensile force. The mRNA and protein levels of vascular endothelial growth factor-α (VEGF-α), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), and transforming growth factor-β1 (TGF-β1) were remarkably increased compared to monolayer-cultured cells. The implanted cell-ECM complex on mice was still noticeable with host cells infiltration and vascularization on 6 months.

Conclusion: Our studies suggested that HuMSCs can be multi-cultivated through adding ascorbic stimulation and ECM containing collagen and hyaluronic acid were enriched around the cells which self-assembly formed a cell-ECM complex. Cell-ECM complex can improve growth factors secretion remarkably which means it may promote wound healing by paracrine.

The primary goal of bone tissue engineering is to fabricate scaffolds that can provide a microenvironment similar to that of natural bone. Therefore, various scaffolds have been designed to replicate the bone structure. Although most tissues exhibit complicated structures, their basic structural unit includes stiff platelets arranged in a staggered micro-array. Therefore, many researchers have designed scaffolds with staggered patterns. However, relatively few studies have comprehensively analyzed this type of scaffold. In this review, we have analyzed scientific research pertaining to staggered scaffold designs and summarized their effects on the physical and biological properties of scaffolds. Compression tests or finite element analysis are typically used to evaluate the mechanical properties of scaffolds, and most studies have performed experiments in cell cultures. Staggered scaffolds improve mechanical strength and are beneficial for cell attachment, proliferation, and differentiation in comparison with conventional designs. However, very few have been studied in vivo experiments. Additionally, studies on the effect of staggered structures on angiogenesis or bone regeneration in vivo, particularly in large animals, are required. Currently, with the prevalence of artificial intelligence (AI)-based technologies, highly optimized models can be developed, resulting in better discoveries. In the future, AI can be used to deepen our understanding on the staggered structure, promoting its use in clinical applications.

Objective: Wear and surface hardness of resin composites are of relevance from the clinical standpoint. With the incorporation of novel filler system, more studies need to be performed to investigate newly marketed resin composites. The objective of this study was to investigate the abrasive wear and surface hardness of dental restorative with different filler types.

Methods: Nanohybrid filled Harmonize (HM) and Tetric N-Ceram (TNC), microhybrid filled Filtek Z250 (Z250), nanofilled Filtek Z350 (Z350) were included in the study. Twelve cylindrical resin composites specimens with 10 mm in diameter and 6 mm in thickness were prepared for abrasive wear test. Eight hundred cycles under 17 kg load were conducted for final wear by CW3-1 wear machine. The specimen was cleaned with an ultrasonic unit for 3 min followed with drying procedure. After measurement of weight loss and the density of specimens, the specimens were kept for measurement of surface hardness. Surface hardness was measured using a micro-hardness tester with a Vickers diamond indenter after polishing. Three specimens of each material were observed by scanning electron microscopy (SEM) after the abrasion to evaluate the morphology of the surface. Data were analyzed using one-way analysis of variance (ANOVA), followed by Tukey HSD test (α = .05).

Results: Z250 performed the least volume wear loss (41.1 ± 2.1 mm³), as well as the hardest value (102.7 ± 2.9 HV). There was no significant difference with the volume wear loss (p = 1.000) and surface hardness (p = 0.874) of HM and TNC. SEM images of nanohybrid filled HM and TNC represented smoother surface compared with other types of resin composites.

Conclusions: Microhybrid Z250 showed the highest wear resistance and surface hardness, nanofilled and nanohybrid resin composites may still face the insufficient of wear and surface hardness quality.

Background: Polycaprolactone (PCL) is a highly recognized synthetic polymer for its biocompatibility, ease of fabrication and mechanical strength in bone tissue engineering. Its applications have extended broadly, including regeneration of oral and maxillofacial lost tissues. Its usefulness has brought attention of researchers to regenerate periodontal lost tissues, including alveolar bone, periodontal ligament and cementum. The aim of this systematic review was to obtain an updated analysis of the contribution of PCL-based scaffolds in the alveolar bone regeneration process.

Methods: This review adheres to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. A computerized search of the PubMed, EBSCO, Scielo and Web of Science databases was performed, restricting literature search to published studies in English or Spanish between January 2002 and March 2023. Database search returned 248 studies which were screened based on title, author names and publication dates.

Results: Data from 17 studies were reviewed and tabulated. All studies combined PCL with other biomaterials (such as Alginate, hydroxyapatite, bioactive glass, poly (lactic-co-glycolic acid)), growth factors (BMP-2, rhCEMP1), and/or mesenchymal stromal cells (adipose-derived, bone marrow, periodontal ligament or gingiva mesenchymal stromal cells). PCL scaffolds showed higher cell viability and osteoinductive potential when combined with bioactive agents. Complementary, its degradation rates were affected by the addition or exposure to specific substances, such as: Dopamine, Cerium Oxide, PLGA and hydrogen peroxide.

Conclusions: PCL is an effective biomaterial for alveolar bone regeneration in periodontally affected teeth. It could be part of a new generation of biomaterials with improved regenerative potential.

Objective: The aim of this study was to investigate the effects of fiber-reinforced composite base material on fracture resistance and fracture pattern of endodontically treated maxillary premolars restored with endocrowns using two different resin nanoceramic computer-aided design and computer-aided manufacturing (CAD/CAM) restorative material.

Methods: Forty extracted sound maxillary premolars with an occlusal reduction of 2 mm above the cementoenamel junction (CEJ) was performed following root canal treatment. Mesial interproximal box was prepared for each tooth at the margin of the CEJ and randomly distributed into four groups (n = 10) as follows: Group A, no resin build-up in the pulp chamber; Group B, 2 mm of fiber-reinforced composite (FRC) build-up (EverX Posterior, GC).; Group C, no resin build-up in pulp chamber; Group D, 2 mm of FRC build-up. Groups A and B were prepared with resin nanoceramic (RNC) consisting ceramic nanofillers (Lava Ultimate 3 M ESPE), while Group C and D were prepared with RNC consisting ceramic nanohybrid fillers (Cerasmart GC Corp). All samples were subjected to 1,200,000 chewing cycles (1.6 Hz, 50 N) and 5000 thermal cycles (5°C-55°C) for artificial aging on a chewing simulator with thermal cycles (CSTC). Samples that survived the CSTC test without being damaged were subjected to a load-to-fracture test.

Results: The highest mean fracture strength was found in Group D (936.0 ± 354.7) and lowest in Group A (684.2 ± 466.9). Fracture strength was higher in groups where FRC was used as a base material than plain restorations. However, there were no significant differences between the Lava and Cerasmart groups with and without FRC (p > 0.05). Most of the samples were irreparably fractured under CEJ.

Conclusion: Using short FRCs as a resin base material did not significantly improve fracture resistance. Cerasmart and Lava blocks had similar fracture resistance and fracture pattern.

Implant restoration is currently the most mainstream method for repairing missing teeth. With the increasing number of plantings, various planting complications begin to be paid attention to. Among them, there are many reports of disability phenomena such as loose and broken abutment screws and broken top screws, which cause the implant to fail or fail to function. In recent years, with the development of computer-aided software and its application in the field of oral treatment, digital guide plates based on 3D printing of oral CBCT scanning data are widely used in oral implants. Therefore, we explore the application prospect of post-core crown restoration after removing broken screws from the implant abutment with a digital guide plate. We reported a case of upper right first molar implant abutment screws broken, which were removed by a digital guide plate and customized turning bur. The resin-matrix ceramics crown post core was prepared, and then the occlusal force was tested by the T-ScanIII system. It provides a reference for the application of digital guide plates in special cases such as broken screws of implant abutment.

Physiological parameters of the oral cavity have a profound impact on any restorative solutions designed for edentulous patients including denture adhesives. This study aims to mathematically quantify the influence of three such variables, namely: the temperature, pH, and the swelling of such adhesives under the influence of saliva on its mechanical behavior. The mathematical quantification is further aimed to implement a material model for such adhesives which considers the impact of such physiological factors. The denture adhesive is experimentally investigated by means of rheological steady state frequency sweep tests to obtain the relaxation spectrum of the material. The relaxation behavior is measured for a wide range of oral cavity temperatures and pH. Also, the adhesive is hydrated and upon swelling to different levels again tested to understand the impact of swelling on the mechanical behavior. The experimentally measured continuous relaxation spectrum is modeled as a viscoelastic material using a discrete set of points based on the Prony series discretization technique. The relaxation spectrums for various temperatures are compared and the possibility of a time-temperature superposition is explored for the model. Similarly, the measured values of Storage and loss modulus are investigated to understand the role of pH and swelling. The results in this study clearly indicated a horizontal shift in the relaxation behavior with increase in temperature. And hence, the time-temperature shift factor was calculated for the adhesive. The relaxation spectrum also showed a strong correlation with swelling of the adhesive and the pH. The influence of these two parameters were captured into the model based on the relaxation time parameter in the Prony series approach. Based on this study the impact of these parameters could be appreciated on the performance and mechanical behavior of denture adhesives and implemented into a Prony series based viscoelastic material model which can be used with numerical simulations.

Limitations with the majority of bone therapeutic treatments include low availability, ethical constraints and low biological compatibility. Although a number of choice materials have been exploited successfully, there has always been scope for improvement as well as development of the next-generation of materials. Herein, scaffolds - developed from gelatin, chitosan and eggshell membranes - were crosslinked using tannic acid, and further infused with selenium and/or copper substituted hydroxyapatite nanoparticles to generate a novel nanocomposite substrate. FESEM images of the nanocomposite scaffolds revealed the presence of interconnected pores, mostly spread over the whole surface of the scaffold, alongside XRD and FTIR profiling that detailed the formation of hydroxyapatite as a sole phase. Moreover, physical characterisation of the nanocomposite confirmed that the hydroxyapatite particulates and the eggshell membrane fibres were uniformly distributed and contributed to the surface roughness of the scaffold. Biocompatibility and cytotoxicity of the novel constructs were assessed using the mouse-derived osteoblastic cell line, MC3T3-E1, and standard cell culture assays. Metabolic activity assessment (i.e. MTS assay), LDH-release profiles and Live/Dead staining demonstrated good cell adhesion, viability, and proliferation rates. Accordingly, this work summarises the successful development of a novel construct which may be exploited as a clinical/therapeutic treatment for bone repair as well as a possible translational application as a novel biomaterial for the drug development pipeline.

Materials like carbamide peroxide or hydrogen peroxide are commonly used for vital teeth bleaching. However, there have been concerns regarding their effect on composite-to-bleached enamel bonding strength. The study investigated the impact of organic and antioxidant agents on composite bond strength in bleached enamel with different dental adhesive solvents. Human third molar teeth were sectioned into buccal and lingual halves. The two main adhesive solvent groups evaluated were acetone and alcohol. Each main group was divided into six groups. The positive control group received no bleaching, the negative control group consisted of bleaching with no surface deoxidization; and other experimental categories involved post-bleach treatments with 95% ethanol, sodium ascorbate (10%), acetone solution, or sodium fluoride solution (1.1%). Following the surface treatment and enamel bonding procedure, nano-hybrid composite cylinders measuring 3 × 2 mm were directly cured over the bleached enamel substrate. The shear bond test was performed after 24-h storage and 12,000 thermocycles on a universal testing machine. In this study, one-way ANOVA was used along with Tukey's HSD tests at a significance level of 0.05. The negative control groups showed significantly lower bond strength than the positive control group. Ethanol surface treatment had superior mean bonding strength in acetone and alcohol-based adhesive solvent groups. The utilization of sodium ascorbate for surface treatment resulted in a significant enhancement of adhesion between the composite material and bleached enamel surface. Sodium fluoride application showed no significant recovery in shear bond strength in both dental adhesive groups. It was concluded that hydrogen peroxide severely compromised the immediate bond strength of composite resin. Surface treatment of bleached enamel with ethanol, sodium ascorbate, and acetone solutions is an effective option for restoring bond strength.

Objectives: Mineral trioxide aggregate (MTA) has a long history of providing predictable clinical outcomes in dental applications especially in endodontic procedures. This bibliometric analysis aimed at evaluating the advancements of research in mineral trioxide aggregate and its use in the field of dentistry, together with the detection of most significant authors, organizations, countries, journals, papers, and the exploration of commonly used keywords using a structured approach.

Materials and method: The search was conducted using the Elsevier's Scopus database, gathering publication information related to MTA published from 1993 and 2021 July. Metadata comprising of titles, abstracts, keywords, authors, organizations, and countries were obtained. Bibliometric evaluators with respect to authors, articles published, journals, keywords, and top countries were scrutinized. Data was analyzed using VOS viewer.

Results: Between 1993 and 2021, an uptrend in the research performed on MTA was identified. Researchers from United States, Brazil, and Iran actively contributed on MTA, while papers from USA were highly cited. The Journal of Endodontics along with International Endodontic Journal were the top contributing academic journals. Hacettepe University, Turkey and Cardiff University from United Kingdom were the top most contributing organizations. Mahmoud Torabinejad was the most cited author. Most commonly used keywords included Mineral trioxide aggregate, silicate, oxide, root canal filling material.

Conclusion: The global rise in the number of publications on mineral trioxide aggregate, tremendous networking and citations have been identified amongst various organizations, authors, and nations through this bibliometric analysis.