Effect of a Thermosensitive Hydroxybutyl Chitosan Hydrogel on Postoperative Sequalae and Quality of Life After Impacted Mandibular Third Molar Extraction.

BACKGROUND: Third molar (M3) extraction is a common surgery in oral and maxillofacial surgery, and composite wound dressings such as hydroxybutyl chitosan (HBC) may improve postoperative sequala following M3 removal. PURPOSE: The study purpose was to measure and compare differences in pain, swelling, trismus, wound healing, and quality of life (QOL) between the HBC and the control sides in patients undergoing M3 removal. STUDY DESIGN, SETTING, SAMPLE: This study is a double-blind, split-mouth, randomized clinical trial. Patients who required M3 removal between June 2022 and May 2023 were included. Exclusion criteria included seafood allergies, smoking, poor oral hygiene, and systemic diseases. PREDICTOR VARIABLE: The predictor variable was the socket treatment technique. Subjects were randomly assigned to the HBC or control (physiological saline) side. MAIN OUTCOME VARIABLE: The primary outcome variables, including pain assessed by visual analog scale, swelling, and maximal incisional opening, were measured on the first, third, and seventh postoperative days. The secondary outcome variables included QOL and wound healing score measured on the third and seventh days after surgery. COVARIATES: The covariates included age, sex, and operation time. ANALYSES: The Shapiro‒Wilk test was used to evaluate the normality of the data distribution. The paired t test or Wilcoxon signed-rank test was adopted. Statistical significance was set at P < .05. RESULTS: The study included 60 patients (mean age: 25.81 ± 4.91; 23 (38%) males, 37 (62%) females). A statistically significant difference in the level of pain (HBC: 37.58 ± 4.39 mm, control: 47.00 ± 4.33 mm, day 1, P < .001; 21.88 ± 3.25 mm, 35.95 ± 1.57 mm, day 3, P < .001), maximal incisional opening (23.92 ± 1.38 mm, 18.22 ± 1.82 mm, day 1, P < .001; 30.00 ± 1.61 mm, 23.78 ± 1.70 mm, day 3, P < .001), and swelling (6.86 ± 0.70 mm, 7.15 ± 0.80 mm, day 3, P = .006) was detected after surgery. A statistically significant difference in QOL was detected (HBC: 13.70 ± 1.65, control: 18.60 ± 2.14, day 3, P < .001). CONCLUSION AND RELEVANCE: The application of HBC hydrogels to wounds after impacted mandibular M3 extraction reduces postoperative sequalae, promotes wound healing and improves postoperative QOL.

Effectiveness of different intrusion modes of maxillary anterior teeth with mini-implants in clear aligner treatment: a three-dimensional finite element analysis.

BACKGROUND: The intrusion of maxillary anterior teeth is often required and there are various intrusion modes with mini-implants in clear aligner treatment. The objective of this study was to evaluate the effectiveness of maxillary anterior teeth intrusion with different intrusion modes, aiming to provide references for precise and safe intrusion movements in clinical practice. METHODS: Cone-beam computed tomography and intraoral optical scanning data of a patient were collected. Finite element models of the maxilla, maxillary dentition, periodontal ligaments (PDLs), clear aligner (CA), attachments, and mini-implants were established. Different intrusion modes of the maxillary anterior teeth were simulated by changing the mini-implant site (between central incisors, between central and lateral incisor, between lateral incisor and canine), loading site (between central incisors, on central incisor, between central and lateral incisor, between lateral incisor and canine), and loading mode (labial loading and labiolingual loading). Ten conditions were generated and intrusive forces of 100 g were applied totally. Then displacement tendency of the maxillary anterior teeth and CA, and stress of the PDLs were analyzed. RESULTS: For the central incisor under condition L14 and for the canine under conditions L11, L13, L23, and L33, the intrusion amount was negative. Under other conditions, the intrusion amount was positive. The labiolingual angulation of maxillary anterior teeth exhibited positive changes under all conditions, with greater changes under linguoincisal loading. The mesiodistal angulation of canine exhibited positive changes under labial loading, while negative changes under linguoincisal loading except for condition L14. CONCLUSIONS: The intrusion amount, labiolingual and mesiodistal angulations of the maxillary anterior teeth were affected by the mini-implant site, loading site, and loading mode. Labial and linguoincisal loading may have opposite effects on the intrusion amount of maxillary anterior teeth and the mesiodistal angulation of canine. The labiolingual angulation of the maxillary incisors would increase under all intrusion modes, with greater increases under linguoincisal loading.

Investigation on the adsorption and desorption behaviors of heavy metals by tire wear particles with or without UV ageing processes.

In recent years, tire wear particles (TWP), as the significant proportion of microplastics (MPs), has adsorbed much attention due to its widespread presence in aquatic ecosystem. Compared with typical MPs, TWP exists significant differences in composition, additives, characteristics and so on. With TWP and polypropylene (PP) as target MPs, Cd2+ and Pb2+ as target pollutants, the adsorption-desorption characteristics of heavy metal ions on original and aged MPs were studied. Compare with the PP, the SBET of TWP increased more significantly after the UV ageing process. Meanwhile, the zeta potential of TWP increased from -8.01 to -14.6 mV and PP from -5.36 to -9.52 mV, and the surface of the TWP were more negatively-charged. In addition, the hydrophilicity of MPs enhanced due to the increased oxygen-containing functional groups after ageing process. Compared with PP, the physicochemical properties of TWP changed more obviously during UV ageing processes. The adsorption results showed that the pseudo-second-order model could better describe the adsorption processes of Cd2+ and Pb2+ on MPs. Meanwhile, the orders of adsorption capacity of MPs for Cd2+ and Pb2+ were aged TWP > aged PP > original TWP > original PP. The phenomenon of adsorption confirmed that TWP had better vector effects for heavy metal ions than PP, and the ageing processes could enhance the adsorption capacity of MPs. Moreover, the desorption results demonstrated that, compared with PP, the TWP (with higher adsorption capacity) also had the better desorption capacity for heavy metal ions in simulated gastric fluid. Compared with PP, the TWP might cause a more serious hazard to aquatic environment and organisms. These investigations would contribute to assessing the potential environmental and biological risk of TWP, especially considering the effect of the ageing process.

Clinical Application of Concentrated Growth Factor Fibrin Combined With Bone Repair Materials in Jaw Defects.

PURPOSE: We investigated the promoting effect of concentrated growth factor (CGF) fibrin on the repair of jaw bone defects. PATIENTS AND METHODS: We designed a clinical trial composed of patients with jaw defects. Forty patients were divided into the test and control groups. CGF fibrin combined with Bio-Oss bone powder (Giestlich Pharma, Wolhusen, Switzerland) was used in the test group. Bio-Oss bone powder alone was used in the control group. The concentration of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-ß in the red blood cell (RBC) layer and CGF gel was measured. At different time points before and after surgery, the serum bone alkaline phosphatase (BAP), osteocalcin, and bone mineral density levels were measured. Regular examinations and computed tomography scans were also performed in the follow-up period. RESULTS: The CGF fibrin available for clinical use was obtained by centrifugation. One day after preparation by centrifugation, the VEGF and TGF-ß concentration in the CGF gel was 2.57-fold and 3.4-fold greater than the concentration in the RBC layer, respectively. The BAP and osteocalcin levels increased at 1 and 12 weeks postoperatively in both groups. Furthermore, the BAP and osteocalcin levels in the test group were significantly greater than those in the control group at 1 and 12 weeks postoperatively (P < .05 for all). The bone mineral density in the bone defect area of the test group was also significantly greater than that of the control group at 6 months postoperatively (P < .05). Evaluation of the regular radiographic scans revealed that the effects in the test group were better than those in the control group. CONCLUSIONS: CGF fibrin could promote new bone formation in jaw defects, with benefit to the healing of bone tissue and, thus, is a promising bone repair material.

Highly permeable artificial water channels that can self-assemble into two-dimensional arrays.

Bioinspired artificial water channels aim to combine the high permeability and selectivity of biological aquaporin (AQP) water channels with chemical stability. Here, we carefully characterized a class of artificial water channels, peptide-appended pillar[5]arenes (PAPs). The average single-channel osmotic water permeability for PAPs is 1.0(± 0.3) × 10(-14) cm(3)/s or 3.5(± 1.0) × 10(8) water molecules per s, which is in the range of AQPs (3.4 ∼ 40.3 × 10(8) water molecules per s) and their current synthetic analogs, carbon nanotubes (CNTs, 9.0 × 10(8) water molecules per s). This permeability is an order of magnitude higher than first-generation artificial water channels (20 to ∼ 10(7) water molecules per s). Furthermore, within lipid bilayers, PAP channels can self-assemble into 2D arrays. Relevant to permeable membrane design, the pore density of PAP channel arrays (∼ 2.6 × 10(5) pores per µm(2)) is two orders of magnitude higher than that of CNT membranes (0.1 ∼ 2.5 × 10(3) pores per µm(2)). PAP channels thus combine the advantages of biological channels and CNTs and improve upon them through their relatively simple synthesis, chemical stability, and propensity to form arrays.

Effects of iron on growth, antioxidant enzyme activity, bound extracellular polymeric substances and microcystin production of Microcystis aeruginosa FACHB-905.

Toxic cyanobacterial blooms have occurred in various water bodies during recent decades and made serious health hazards to plants, animals and humans. Iron is an important micronutrient for algal growth and recently, the concentration of which has increased remarkably in freshwaters. In this paper, the cyanobacterium Microcystis aeruginosa FACHB-905 was cultivated under non-iron (0µM), iron-limited (10µM) and iron-replete (100µM) conditions to investigate the effects of iron on growth, antioxidant enzyme activity, EPS and microcystin production. The results showed that algal cell density and chlorophyll-a content were maximal at the highest iron concentration. Antioxidant enzymes activity increased notably under all three conditions in the early stage of experiment, of which the SOD activity recovered soon from oxidative stress in 10µM group. The productions of some protein-like substances and humic acid-like substances of bound EPS were inhibited in iron-containing groups in the early stage of experiment while promoted after the adaptation period of Microcystis aeruginosa. Iron addition is a factor affecting the formation of cyanobacterial blooms through its impact on the content of LB-EPS and the composition of TB-EPS. The intracellular MC-LR concentration and the productivity potential of MC-LR were the lowest in 0µM group and highest in 10µM group. No obvious extracellular release of MC-LR was observed during the cultivation time. Therefore, iron addition can promote the physiological activities of M. aeruginosa, but a greater harm could be brought into environment under iron-limited (10µM) condition than under iron-replete (100µM) condition.

Hydrogen-bonded helical hydrazide oligomers and polymer that mimic the ion transport of gramicidin A.

A new series of hydrogen-bonded helical aromatic hydrazide oligomers and polymer that bear phenylalanine tripeptide chains have been designed and synthesized. It was revealed that the helical structures could insert into lipid bilayers to form unimolecular channels. The longest oligomeric and polymeric helical channels exhibited an NH4(+)/K(+) selectivity that was higher than that of natural gramicidin A, whereas the transport of a short helical channel for Tl(+) could achieve an efficiency as high as that of gramicidin A.

The long-term release and particle fracture behaviors of nanoplastics retained in porous media: Effects of surfactants, natural organic matters, antibiotics, and bacteria.

The transport of nanoplastics (NPs) in porous media has received a lot of attention, but the studies on the long-term release of NPs retained in porous media and the particle fracture during this process are seriously lacking. For filling this deficiency, we examined the individual or synergistic effects of surfactants, natural organic matters (NOMs), antibiotics, and bacteria on the desorption, long-term release, and particle fracture behaviors of polystyrene NPs (PS-NPs) retained in porous media. It was found that the change in hydrophilicity of PS-NPs dominated the long-term release of PS-NPs retained in porous media when surfactants were present. In the single system of surfactants and the dual system of surfactants and NOMs, the release of PS-NPs were improved owing to the increasing hydrophilicity of PS-NPs, although cationic surfactants also reduced the electrostatic repulsion between PS-NPs and porous media. Increasing antibiotic concentration reduced the electrostatic repulsion between PS-NPs and porous media to inhibit the release of PS-NPs. When bacteria were present whether containing antibiotics or not, the effects on roughness of PS-NPs dominated the release of PS-NPs. The effects of surfactants and NOMs on the PS-NP desorption were similar with the long-term release, with changes in hydrophilicity dominating the process. Whereas the effects of antibiotics and bacteria on the PS-NP desorption were different with the long-term release. Surfactants and NOMs in the presence of surfactants inhibited the fracture of PS-NPs by increasing the hydrophilicity of PS-NPs brought about the coating of water molecules on PS-NPs for protection. Antibiotics had no significant effects on the fracture of PS-NPs due to unaltered vertical forces on PS-NPs and no protective effect. Bacteria in the presence or absence of antibiotics inhibited the fracture of PS-NPs by coating PS-NPs retained in porous media to protect PS-NPs from fracture.

Polystyrene microplastics alter the trophic transfer and biotoxicity of fluoxetine in an aquatic food chain.

Microplastics (MPs) and fluoxetine are ubiquitous emerging pollutants in aquatic environments that may interact with each other due to the carrier effects of MPs, posing unpredictable risks to non-target organisms. However, limited studies have focused on the carrier effects of MPs in the aquatic food chain. This study evaluated the influences of polystyrene MPs on the trophic transfer and biotoxicity of fluoxetine in a simple food chain composed of brine shrimp (Artemia nauplii) and zebrafish (Danio rerio). The finding reveals that carrier effects of MPs enhanced the accumulation of waterborne fluoxetine in brine shrimp, but suppressed that in zebrafish due to the distinct retention times. The accumulated fluoxetine in shrimp was further transferred to fish through the food chain, which was alleviated by MPs due to their cleaning effects. In addition, the specific neurotransmission biotoxicity in fish induced by fluoxetine was mitigated by MPs, whilst the oxidative damage, apoptosis, and immune responses in zebrafish were reversely enhanced by MPs due to the stimulating effect. These findings highlight the alleviating effects of MPs on the trophic transfer and specific biotoxicity of fluoxetine in the food chain, providing new insights into the carrier effects of MPs in aquatic environments in the context of increasing global MP pollution.