Zn and Ag Doping on Hydroxyapatite: Influence on the Adhesion Strength of High-Molecular Polymer Polycaprolactone.

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.

Comparison of the efficacy of different biodegradable membranes in guided bone/tissue regeneration: a systematic review and network meta-analysis.

Guided bone/tissue regeneration (GBR/GTR) is commonly used in dental treatment. The desired bone/tissue regeneration is achieved by placing a barrier membrane over the defect to avoid the downward growth of faster-growing connective and epithelial tissue into the defect. This review aimed to evaluate osteogenic properties, degradation characteristics, and postoperative complications of eight biodegradable membranes in animal experiments, including non-crosslinked collagen membrane (NCCM), crosslinked collagen membrane (CCM), silk membrane (SM), polylactic-co-glycolic acid, polylactic acid, polyethylene glycol hydrogel, polycaprolactone (PCL), and magnesium alloys. Seven electronic databases (PubMed, Embase, Web of Science, Cochrane Library, Science Direct, Wiley, Scopus and Google Scholar) were screened. Study selection, data extraction and quality assessment were made in duplicate. The SYRCLE assessment tool, CERQual (Confidence in the Evidence from Reviews of Qualitative Research) tool and GRADE tool were used to grade the risk of bias and level of evidence. A total of 2512 articles were found in the electronic database. Finally, 94 articles were selected, of which 53 were meta-analyzed. Surface under the cumulative ranking curve showed the best results for new bone formation in the magnesium barrier membrane group, followed by SM, PCL, NCCM, and CCM. Qualitative analysis showed good biocompatibility for natural polymer membranes and a longer degradation time for synthetic polymer membranes. In addition, 34 studies all showed high bias risks, while other studies had unclear bias risks. Natural polymer membranes were more effective for bone regeneration and magnesium alloys were proved to be promising barrier materials that warrant future research.

A Systematic Review and Network Meta-Analysis of Biomedical Mg Alloy and Surface Coatings in Orthopedic Application.

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.

Effect of Different Membranes on Vertical Bone Regeneration: A Systematic Review and Network Meta-Analysis.

This study is aimed at performing a systematic review and a network meta-analysis of the effects of several membranes on vertical bone regeneration and clinical complications in guided bone regeneration (GBR) or guided tissue regeneration (GTR). We compared the effects of the following membranes: high-density polytetrafluoroethylene (d-PTFE), expanded polytetrafluoroethylene (e-PTFE), crosslinked collagen membrane (CCM), noncrosslinked collagen membrane (CM), titanium mesh (TM), titanium mesh plus noncrosslinked (TM + CM), titanium mesh plus crosslinked (TM + CCM), titanium-reinforced d-PTFE, titanium-reinforced e-PTFE, polylactic acid (PLA), polyethylene glycol (PEG), and polylactic acid 910 (PLA910). Using the PICOS principles to help determine inclusion criteria, articles are collected using PubMed, Web of Science, and other databases. Assess the risk of deviation and the quality of evidence using the Cochrane Evaluation Manual, and GRADE. 27 articles were finally included. 19 articles were included in a network meta-analysis with vertical bone increment as an outcome measure. The network meta-analysis includes network diagrams, paired-comparison forest diagrams, funnel diagrams, surface under the cumulative ranking curve (SUCRA) diagrams, and sensitivity analysis diagrams. SUCRA indicated that titanium-reinforced d-PTFE exhibited the highest vertical bone increment effect. Meanwhile, we analyzed the complications of 19 studies and found that soft tissue injury and membrane exposure were the most common complications.