[A retrospective cohort study of risk factors for prevalence of implant biological complications].

PURPOSE: To analyze the risk factors of biological complications after implant-fixed denture restoration. METHODS: Seven hundred and twenty-five implants were placed between March 2012 and March 2016. Follow-up period was 5 to 9 years. The implant mucosal index (IMI) and implant marginal bone loss (MBL) were measured at 3 months-1 year, 2-3 years, 4-5 years, 6-7 years and 8-9 years after restoration. The prevalence and risk factors of peri-implantitis and mucositis were analyzed. SPSS 28.0 software package was used to analyze the date. RESULTS: The implant survival rate of 5 years was 98.7%. The prevalence of mucositis and peri-implantitis were 37.5% and 8.3% at 8 to 9 years. Smoking, periodontitis, narrow diameter, rough neck , anterior location, bone augmentation caused higher prevalence of peri-implantitis or mucositis (P＜0.05). CONCLUSIONS: Smoking, periodontitis, implant diameter, implant design, implant location and bone augmentation are the risk factors of implant biological complications.

Calcium-Zinc Phosphate Chemical Conversion Coating Facilitates the Osteointegration of Biodegradable Zinc Alloy Implants by Orchestrating Macrophage Phenotype.

Zinc (Zn) alloys provide a new generation for orthopedic applications due to their essential physiological effects and promising degradation properties. However, excessive release of Zn ions (Zn2+ ) during degradation and the severe inflammatory microenvironment are not conducive to osseointegration, which is determined by the characteristics of the implant surface. Therefore, it is essential to modulate the release rate of Zn alloys by surface modification technology and endow them with anti-inflammatory and osteogenic effects. In this study, two kinds of phosphate chemical conversion (PCC) coatings with different compositions and morphological structures are prepared, namely Zn-P (with disk-like crystals) and Ca-Zn-P (with lamellar crystals). Although all the PCC-coated Zn implants have low cytotoxicity, Ca-Zn-P show better osteoimmunomodulation effects in several aspects: the induction of the M2-phenotype macrophage polarization and thus promotion of osteogenesis in vitro; the regulation of the bone immune microenvironment which is conducive to tissue regeneration and osseointegration in vivo; and the release of ions (through PI3K/AKT and Wnt signaling pathways) and the morphological structures (through RhoGTPase signaling pathways) act as possible mechanisms of M2 polarization. The Ca-Zn-P coating can be considered to provide new insights into bone immunomodulation and osseointegration.

Production, immobilization and characterization of beta-glucosidase for application in cellulose degradation from a novel Aspergillus versicolor.

Beta-glucosidase (EC 3.2.1.21) catalyzes the hydrolysis of cellobiose and cellooligosaccharides containing (1 â†’ 4)-beta-glycosidic bonds to glucose, which is crucial in cellulosic ethanol production. In this study, Aspergillus versicolor, a novel highly productive beta-glucosidase strain, was first isolated from Camptotheca acuminata seeds. The highest beta-glucosidase activity with 812.86 U/mL was obtained by using the response surface methodology, and a 14.4-fold has increased compared to the control. The beta-glucosidase was then purified to homogeneity with recovery yield and specific activity of 25.98% and 499.15 U/mg, respectively. To enhance its stability and recyclability, the purified beta-glucosidase was first immobilized onto magnetic MnO2 by electrostatic adsorption. The immobilized materials were characterized by FR-IT, TEM and FE-SEM. Compared with the free beta-glucosidase, the immobilized enzyme exhibited enhanced thermal stability (1.5-fold raise in half-life at 50 °C), and reusability (holding over 60% activity after eight cycles), besides, the optimum pH has increased to 6.0. Substrate specificity research suggested that the enzyme had high hydrolytic activity on cellobiose. It also had a hydrolysis effect on (1 â†’ 3) and (1 â†’ 6)-beta-glycosidic linkages. Application trials in cellulose hydrolysis revealed that the immobilized enzyme was comparatively more effective. Our results suggested this novel immobilized beta-glucosidase makes a promising alternative for the cellulosic ethanol production.