Three-dimensional (3D) printing technologies are advanced manufacturing technologies based on computer-aided design digital models to create personalized 3D objects automatically. They have been widely used in the industry, design, engineering, and manufacturing fields for nearly 30 years. Three-dimensional printing has many advantages in process engineering, with applications in dentistry ranging from the field of prosthodontics, oral and maxillofacial surgery, and oral implantology to orthodontics, endodontics, and periodontology. This review provides a practical and scientific overview of 3D printing technologies. First, it introduces current 3D printing technologies, including powder bed fusion, photopolymerization molding, and fused deposition modeling. Additionally, it introduces various factors affecting 3D printing metrics, such as mechanical properties and accuracy. The final section presents a summary of the clinical applications of 3D printing in dentistry, including manufacturing working models and main applications in the fields of prosthodontics, oral and maxillofacial surgery, and oral implantology. The 3D printing technologies have the advantages of high material utilization and the ability to manufacture a single complex geometry; nevertheless, they have the disadvantages of high cost and time-consuming postprocessing. The development of new materials and technologies will be the future trend of 3D printing in dentistry, and there is no denying that 3D printing will have a bright future.

Graphene can be used as a drug carrier of doxorubicin (DOX) to reduce the side effects of doxorubicin. However, there is limited research on the surface chemical modifications and biological effects of graphene oxide (GO). Therefore, it is necessary to explore the DOX affinity of different oxygen-containing functional groups in the graphene system. We constructed graphene system models and studied the structure and distribution of epoxy and hydroxyl groups on the carbon surface. Based on molecular dynamics simulations and density functional theory (DFT), we investigated the interaction between DOX and either pristine graphene or GO with different ratios of oxygen-containing groups. The hydroxyl groups exhibited a stronger affinity for DOX than the epoxy groups. Therefore, the DOX loading capacity of graphene systems can be adjusted by increasing the ratio of hydroxyl to epoxy groups on the carbon surface.

Magnesium alloys have great application prospects as ideal bone implant materials. However, their poor corrosion resistance limits their clinical orthopedic application. Surface modification promotes the corrosion resistance of magnesium. Conversion coatings, such as calcium phosphate (Ca-P) coating, microarc oxidation (MAO) treatment, and fluoride (FLU) treatment, have been extensively investigated in in vivo studies. This systematic review and network meta-analysis compared the influence of different conversion coatings on bone repair, material properties, and systemic host response in orthopedic applications. Using the PICOS model, the inclusion criteria for biodegradable magnesium and its alloys were determined for in vivo studies. Four databases were used. The standard and weight mean differences with 95% confidence intervals were used to analyze new bone formation and degradation rate. Network structure and forest plots were created, and ranking probabilities were estimated. The risk of bias and quality of evidence were assessed using SYRCLE, CERQual, and GRADE tools. In the qualitative analysis, 43 studies were selected, and the evaluation of each outcome indicator was not entirely consistent from article to article. In the quantitative analysis, 21 articles were subjected to network meta-analysis, with 16 articles on implant degradation and 8 articles for new bone formation. Additionally, SUCRA indicated that Ca-P coating exhibited the highest corrosion resistance, followed by FLU treatment. MAO demonstrated the best capability for new bone formation, followed by Ca-P coating. Ca-P coating exhibited the highest overall performance. To conclude, coated Mg can promote better new bone formation than bare Mg and has considerable biocompatibility. Ca-P-coated Mg and MAO-coated Mg have the greatest potential to significantly promote corrosion resistance and bone regeneration, respectively. The findings of this study will provide a theoretical basis for the investigation of composite coatings and guidance for the orthopedic application of Mg bone implants.

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Tissue adhesive has notable clinical benefits in hernia repair fixation. A novel poloxamine tissue adhesive was previously shown to successfully bond collagen tissue with adequate adhesive strength. In application related to attachment of polypropylene (PP) mesh, the adhesive strength between the mesh and poloxamine hydrogel adhesive is limited by the hydrophobicity of PP monofilaments and lack of covalent bond formation. The purpose of this study was to compare two different surface modifications [bovine serum albumin (BSA) adsorption and poly-glycidyl methacrylate/ human serum albumin (PGMA/HSA) grafting] of PP mesh for improving the adhesive strength between poloxamine hydrogel adhesive and PP mesh. The PGMA/HSA surface modification significantly improved the adhesive strength for meshes attached with poloxamine hydrogel tissue adhesive compared with unmodified meshes and meshes modified by BSA adsorption. An area of 1 cm 2 adhesive provided for a maximum adhesive strength of 65-70 kPa for meshes modified by PGMA/HSA, 4-13 kPa for meshes modified by BSA, and 22-45 kPa for unmodified meshes. Optical microscopy and infrared spectroscopy (FTIR) confirmed the improved adhesive strength was achieved through mechanical interlock of the hydrogel tissue adhesive into the PP mesh pores and chemical bonding of the albumin after successful PGMA/HSA grafting onto the PP monofilaments.How to cite this article: Lu X, Khanna A, Luzinov I, Nagatomi J, Harman M. 2019. Surface modification of polypropylene surgical meshes for improving adhesion with poloxamine hydrogel adhesive. J Biomed Mater Res

As computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have matured, three-dimensional (3D) printing materials suitable for dentistry have attracted considerable research interest, owing to their high efficiency and low cost for clinical treatment. Three-dimensional printing technology, also known as additive manufacturing, has developed rapidly over the last forty years, with gradual application in various fields from industry to dental sciences. Four-dimensional (4D) printing, defined as the fabrication of complex spontaneous structures that change over time in response to external stimuli in expected ways, includes the increasingly popular bioprinting. Existing 3D printing materials have varied characteristics and scopes of application; therefore, categorization is required. This review aims to classify, summarize, and discuss dental materials for 3D printing and 4D printing from a clinical perspective. Based on these, this review describes four major materials, i.e., polymers, metals, ceramics, and biomaterials. The manufacturing process of 3D printing and 4D printing materials, their characteristics, applicable printing technologies, and clinical application scope are described in detail. Furthermore, the development of composite materials for 3D printing is the main focus of future research, as combining multiple materials can improve the materials’ properties. Updates in material sciences play important roles in dentistry; hence, the emergence of newer materials are expected to promote further innovations in dentistry.

In this study, density functional theory was employed to calculate the adsorption of polycaprolactone (PCL) by pure hydroxyapatite (HA), Zn-doped HA, and Ag-doped HA, and the interaction of PCL on the surface of HA (001) was simulated. The results show that there was significant electron transfer between the carbonyl O in PCL and the Zn, Ag, and Ca in HA, forming coordinate bonds. The binding energies of Ag-doped HA/PCL and Zn-doped HA/PCL were much higher than those of HA/PCL. HA doped with Ag had the highest binding energy to PCL. Therefore, we believe that when HA is doped with Ag atoms, its adsorption capacity for PCL can be increased. The results obtained in this study can be used as a guide for the development of HA/PCL bone graft composite material doped with appropriate metal ions to improve its adsorption capacity.

Bioactive glass, as an ideal biomaterial, is not suitable for load-bearing parts because of its high brittleness and has been applied for surface modification to manufacture composite materials. Titanium alloy is bio-inert and prone to loosening, which leads to implant failure and infection after implantology. Applying bioactive glass to titanium and its alloys in the form of coating combines titanium metal’s superior mechanical properties and bioglass’s good biological properties. In this review, the authors searched and screened four databases, including Web of Science, PubMed, Embase, and Scopus, for articles published since 2013, finally, 49 articles were included to investigate the biological properties of bioactive glass coatings on titanium and its alloys. From the perspective of methodology, this review aims to summarize the methodologies performed for detecting the biological properties including biocompatibility and bioactivity of coatings were also concluded, covering the experimental process and principle of the included studies, therefore, providing learning materials for new researchers in material science and biotechnology.