OBJECTIVE: Systematic review and meta-analysis on laboratory studies aimed to answer whether there is a difference in fracture resistance and fracture mode of structurally compromised teeth restored with direct composite restorations reinforced with short glass-fiber or bidirectional polyethylene fiber substructure, and between the two different fiber-reinforcement types. METHODS: An electronic literature search was conducted in Medline, Scopus, Web of Science, Lilacs, Google Scholar, Cochrane Library, and University Library databases. The last search was conducted on 16 November 2023. Only studies looking at Ribbond-reinforced restorations and/ or the use of EverX Posterior within restorations were included. Data were categorized and analyzed based on specific outcome measures including fracture resistance and fracture mode. Data from individual studies were divided into premolars and molars for each material category and then collated to compare the mean differences in fracture resistance between control groups (composite restorations) and intervention groups (fiber-reinforced composite restorations). RESULTS: From the initial 1266 articles identified, 23 laboratory-based studies were included for quantitative analysis. Twenty articles had an overall low risk of bias and 3 had an overall unclear risk of bias. The pooled estimate of the effect favored the intervention groups as having statistically significant higher fracture resistance when compared to control groups. CONCLUSIONS: Both fiber types improve fracture resistance and the fracture mode of structurally compromised teeth is equally efficient. Application technique deserves attention. Ribbond could be placed in a single layer at the cavity floor, whereas EverX Posterior should replace missing dentin in an anatomically shaped way.
- MeSH
- fraktury zubů * prevence a kontrola MeSH
- lidé MeSH
- polyethyleny MeSH
- sklo chemie MeSH
- složené pryskyřice * terapeutické užití chemie MeSH
- trvalá zubní náhrada * metody MeSH
- zubní materiály chemie MeSH
- zuby-sanace - selhání MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- práce podpořená grantem MeSH
- systematický přehled MeSH
The current global scenario presents us with a growing increase in infections caused by fungi, referred to by specialists in the field as a "silent epidemic", aggravated by the limited pharmacological arsenal and increasing resistance to this therapy. For this reason, drug repositioning and therapeutic compound combinations are promising strategies to mitigate this serious problem. In this context, this study investigates the antifungal activity of the non-toxic, low-cost and widely available cationic polyelectrolyte Poly(diallyldimethylammonium chloride) (PDDA), in combination with different antifungal drugs: systemic (amphotericin B, AMB), topical (clioquinol, CLIO) and oral (nitroxoline, NTX). For each combination, different drug:PDDA ratios were tested and, through the broth microdilution technique, the minimum inhibitory concentration (MIC) of these drugs in the different ratios against clinically important Candida species strains was determined. Overall, PDDA combinations with the studied drugs demonstrated a significant increase in drug activity against most strains, reaching MIC reductions of up to 512 fold for the fluconazole resistant Candida krusei (Pichia kudriavzevii). In particular, the AMB-PDDA combination 1:99 was highly effective against AMB-resistant strains, demonstrating the excellent profile of PDDA as an adjuvant/association in novel antifungal formulations with outdated conventional drugs.
- MeSH
- amfotericin B farmakologie MeSH
- antifungální látky * farmakologie MeSH
- Candida * účinky léků MeSH
- fungální léková rezistence MeSH
- kandidóza mikrobiologie farmakoterapie MeSH
- kvartérní amoniové sloučeniny * farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- Pichia MeSH
- polyelektrolyty farmakologie MeSH
- polyethyleny farmakologie chemie MeSH
- synergismus léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF STUDY: Total joint replacements (TJR) have become the cornerstone of modern orthopedic surgery. A great majority of TJR employs ultrahigh molecular weight polyethylene (UHMWPE) liners. TJR manufacturers use many different types of UHMWPE, which are modified by various combinations of crosslinking, thermal treatment, sterilization and/or addition of biocompatible stabilizers. The UHMWPE modifications are expected to improve the polymer's resistance to oxidative degradation and wear (release of microparticles from the polymer surface). This manuscript provides an objective, non-commercial comparison of current UHMWPE formulations currently employed in total knee replacements. MATERIALS AND METHODS: UHMWPE liners from 21 total knee replacements (TKR) were collected which represent the most implanted liners in the Czech Republic in the period 2020-2021. The UHMWPEs were characterized using several methods: infrared microspectroscopy (IR), non-instrumented and instrumented microindentation hardness testing (MH and MHI), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility measurements. The above-listed methods yielded quite complete information about the structure and properties of each UHMWPE type, including its potential long-term oxidation resistance. RESULTS: For each UHMWPE liner, IR yielded information about immediate oxidative degradation (in the form of oxidation index, OI), level of crosslinking (trans-vinylene index, VI) and crystallinity (CI). The MH and MHI testing gave information about the impact of structure changes on mechanical properties. The remaining methods (DSC, TGA, and solubility measurements) provided additional information regarding the structure changes and resistance to long-term oxidative degradation. Statistical evaluation showed significant differences among the samples as well as interesting correlations among the UHMWPE modifications, structural changes, and mechanical performance. DISCUSSION: Surprisingly enough, UHMWPE materials from different manufacturers showed quite different properties, including the resistance against the long-term oxidative degradation, which is regarded as one of the main reasons of TJR failures. The most promising UHMWPE types were crosslinked materials with biocompatible stabilizers. CONCLUSIONS: Current UHMWPE liners from different manufactures used in total knee replacements exhibit significantly different structure and properties. From the point of view of clinical practice, the traditional UHMWPE types, which contained residual radicals from irradiation and/or gamma sterilization, showed inferior resistance to oxidative degradation and should be avoided. The best properties were observed in modern UHMWPE types, which combined crosslinking, biocompatible stabilizers, and sterilization by ethylenoxide or gas plasma. KEY WORDS: UHMWPE; knee replacements; oxidative degradation; infrared spectroscopy; microhardness.
- MeSH
- biokompatibilní materiály chemie MeSH
- diferenciální skenovací kalorimetrie MeSH
- lidé MeSH
- polyethyleny * chemie MeSH
- protézy - design MeSH
- protézy kolene * MeSH
- termogravimetrie MeSH
- testování materiálů * metody MeSH
- totální endoprotéza kolene * přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- srovnávací studie MeSH
BACKGROUND: Surgical site infection (SSI) is the most consistently reported complication of cranioplasty. No material showed a categorical superiority in the incidence of infection. Porous polyethylene (PE) is considered a low risk material regarding SSI. However, the literature data are very limited. Thus, our objective was to verify the assumed low incidence of SSI after PE cranioplasty in patients at high risk of SSI. The primary objective was the infection rate, while secondary objectives were implant exposure, revision and cosmetic results. METHOD: Patients who underwent three-dimensional (3D) personalized PE cranioplasty in the period 2014-2023 were evaluated prospectively. Only patients with an increased risk of SSI, and a satisfactory clinical conditions were included in the study. RESULTS: Thirty procedures were performed in 30 patients. Cranioplasty was performed 23 times after hemispheric decompressive craniectomy, five times after limited size craniotomy and two times after bifrontal decompressive craniectomy. Risk factors for the development of infection were 18 previous SSIs, 16 previous repeated revision surgeries, four intraoperatively opened frontal sinuses and two times radiotherapy. Neither infection nor implant exposure was detected in any patient. All patients were satisfied with the aesthetic result. In two cases, a revision was performed due to postoperative epidural hematoma. CONCLUSIONS: Three-dimensional personalized PE cranioplasty is associated with an extremely low incidence of SSI even in high-risk patients. However, our conclusions can only be confirmed in larger studies.
- MeSH
- dekompresní kraniektomie škodlivé účinky metody MeSH
- dospělí MeSH
- infekce chirurgické rány * epidemiologie etiologie MeSH
- kraniotomie škodlivé účinky metody MeSH
- lebka chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- polyethylen MeSH
- poréznost MeSH
- prospektivní studie MeSH
- rizikové faktory MeSH
- senioři MeSH
- zákroky plastické chirurgie * metody škodlivé účinky MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Total knee arthroplasty (TKA) with all-polyethylene tibial (APT) components has shown comparable survivorship and clinical outcomes to that with metal-backed tibial (MBT). Although MBT is more frequently implanted, APT equivalents are considered a low-cost variant for elderly patients. A biomechanical analysis was assumed to be suitable to compare the response of the periprosthetic tibia after implantation of TKA NexGen APT and MBT equivalent. METHODS: A standardised load model was used representing the highest load achieved during level walking. The geometry and material models were created using computed tomography data. In the analysis, a material model was created that represents a patient with osteopenia. RESULTS: The equivalent strain distribution in the models of cancellous bone with an APT component showed values above 1000 με in the area below the medial tibial section, with MBT component were primarily localised in the stem tip area. For APT variants, the microstrain values in more than 80% of the volume were in the range from 300 to 1500 με, MBT only in less than 64% of the volume. CONCLUSION: The effect of APT implantation on the periprosthetic tibia was shown as equal or even superior to that of MBT despite maximum strain values occurring in different locations. On the basis of the strain distribution, the state of the bone tissue was analysed to determine whether bone tissue remodelling or remodelling would occur. Following clinical validation, outcomes could eventually modify the implant selection criteria and lead to more frequent implantation of APT components.
PURPOSE: This study aims to compare total knee replacement (TKA) with NexGen All-Poly (APT) and NexGen Metal-Backed (MBT) in terms of implant survivorship, reasons leading to implant failure and functional results of defined age categories. METHODS: A single-centre, retrospective evaluation of 812 patients who underwent knee replacement with NexGen CR between 2005 and 2021, comparing a modern congruent APT component to a modular MBT equivalent component using a similar surgical technique at a notable mean follow-up duration. Implant survival, functional outcomes using the Knee Society Score and range of motion were evaluated and compared in different age categories. RESULTS: Of the 812 NexGen CR TKAs performed at our institution, 410 (50.4%) used APT components and 402 (49.6%) MBT components. The survival rate of NexGen APT was 97.1% and that of NexGen MBT was 93.2% (p = 0.36). Removal of the implant occurred overall in 15 cases, for MBT in ten cases, and for APT in four cases. The FS was proved to be significantly higher when APT components were implanted in younger patients than for MBT (p = 0.005). A similar range of motion between the components was recorded (p = 0.1926). CONCLUSION: Under defined conditions, we measured the clinical results of implants from a single manufacturer implanted in a single department using a similar surgical technique. Considering the limitations, we suggest that all-polyethylene tibial components are equal or even superior to metal-backed ones across the examined age categories.
- MeSH
- kovy MeSH
- lidé MeSH
- polyethylen MeSH
- protézy - design MeSH
- protézy kolene * MeSH
- retrospektivní studie MeSH
- totální endoprotéza kolene * škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cíl: Kranioplastika je dle literatury zatížena až 50% rizikem vzniku komplikací. Mezi nejčastější patří ranná infekce. Porózní polyethylen je považován za alogenní materiál s nejnižším výskytem infekce. Cílem práce bylo ověření předpokládaného nízkého výskytu ranné infekce po implantaci porózního polyethylenu i v rizikovém terénu. Sekundárním cílem bylo posouzení uvolnění implantátu fixovaného pomocí minidlah a obnažení implantátu. Metodika: Prospektivně jsme sledovali a hodnotili skupinu 12 nemocných, u kterých byla v období 2014–2021 provedena na míru počítačově modelovaná 3D kranioplastika z porózního polyethylenu v rizikovém terénu. Rizikový terén byl definován jako předchozí ranná infekce, opakované revizní operace s resorpcí nebo uvolněním kostní ploténky nebo implantátu a otevřený frontální sinus. Výskyt uvedených komplikací byl hodnocen prostřednictvím fyzikálního vyšetření lokálního nálezu a CT. Výsledky: Celkem jsme provedli 12 kranioplastik u 12 nemocných. Průměrný follow-up byl 47 měsíců. V pěti případech byla kranioplastika indikována z důvodu ranné infekce, čtyřikrát po opakovaných revizních operacích s resorpcí nebo uvolněním kostní ploténky nebo implantátu a ve třech případech kvůli otevřenému frontálnímu sinu. Osm pacientů mělo kombinaci dvou rizikových faktorů. U žádného nemocného nebyla po kranioplastice zaznamenána ranná infekce. Ve všech případech byla fixace minidlahami dostatečná a u žádného nemocného nebylo zaznamenáno obnažení implantátu. Závěr: V našem souboru jsme potvrdili vysokou spolehlivost porózního polyethylenu z pohledu minimálního rizika ranné infekce i v rizikovém terénu.
Aim: According to the literature, cranioplasty is associated with up to 50% risk of complications. The most common complication is wound infection. Porous polyethylene is considered to be an allogenic material with the lowest rate of infection. The aim of this study was to verify the assumed low rate of wound infections after implantation of porous polyethylene, even in high-risk terrain. The secondary objective was to assess the loosening of the implant fixed with mini-plates and the exposure of the implant. Methods: A group of 12 patients who underwent a customized computer-modeled 3D cranioplasty from porous polyethylene in a high-risk terrain was followed prospectively between 2014 and 2021. The high-risk terrain was defined as a previous wound infection, repeated surgeries with resorption or loosening of the bone or an implant and an open frontal sinus. The occurrence of listed complications was evaluated through physical examination and CT. Results: In total, there were 12 cranioplasties performed in 12 patients. The average follow-up period was 47 months. In five cases, cranioplasty was indicated after an wound infection, four times after repeated surgeries with the resorption or loosening of the bone or implant, and in three cases in the terrain of the open frontal sinus. Eight patients had a combination of two risk factors. No patient had wound infection after cranioplasty. In all cases, fixation with mini-plates was sufficient, and no implant was exposed. Conclusion: Our study confirmed high reliability and low risk of wound infection of porous polyethylene, even in a high-risk terrain.
- Klíčová slova
- kranioplastika,
- MeSH
- 3D tisk MeSH
- alografty MeSH
- dekompresní kraniektomie * MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- plastická chirurgie MeSH
- polyethylen * terapeutické užití MeSH
- pooperační komplikace prevence a kontrola MeSH
- prospektivní studie MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
Greater wax moth (GWM), Galleria mellonella (Lepidoptera: Pyralidae), is a highly destructive honey bee pest prevalent throughout the world. It is considered as a major factor to the alarming decline in honey bee population. GWM destroys active honey combs as it feeds on the beeswax and lays eggs in bee hives, and the primary food of their larva is beeswax. Beeswax is a polymer composed mainly of saturated and unsaturated, linear and complex monoesters, and hydrocarbons. The most frequent bond in beeswax is ethene (CH2-CH2) which is also found in the common plastic polyethylene. As wax-digestion is not a common animal character, we hypothesized about a possible role of GWM gut microflora in the process; which could possibly degrade polyethylene-like polymers as well. This study was aimed to identify the GWM gut microflora via culture-dependant approach. We characterized several bacterial species based on the culture characteristics, Gram-reaction, and various biochemical tests. Sequencing of 16S-rDNA revealed nine bacterial and one microalgal species from GWM gut. The bacterial species included Gram-positive Exiguobacterium aestuarii, Bacillus circulans, Microbacterium zaea, Microbacterium sp. and Enterococcus faecalis; Gram-negative Agrobacterium sp., Sphingomonas pseudosanguinis, Sphingobium yanoikuyae and Acinetobacter radioresistens; the microalgae was Picochlorum oklahomensis. Some of them have been previously reported to degrade polycyclic aromatic hydrocarbon, low-density polyethylene, and 2-methylphenanthrene. Meanwhile, the microalga, P. oklahomensis, was reported to steal bacterial genes to adapt with abiotic stresses. Further investigation is necessary to explore the precise details about polymer degrading capabilities of these microbes; nevertheless, this study builds a foundation for elaborate and advanced future research.
Although many noble metals are known for their antibacterial properties against the most common pathogens, such as Escherichia coli and Staphylococcus epidermidis, their effect on healthy cells can be toxic. For this reason, the choice of metals that preserve the antibacterial effect while being biocompatible with health cells is very important. This work aims to validate the effect of gold on the biocompatibility of Au/Ag nanowires, as assessed in our previous study. Polyethylene naphthalate (PEN) was treated with a KrF excimer laser to provide specific laser-induced periodic structures. Then, Au was deposited onto the modified PEN via a vacuum evaporation method. Atomic force microscopy and scanning electron microscopy revealed the dependence of the surface morphology on the incidence angle of the laser beam. A resazurin assay cytotoxicity test confirmed safety against healthy human cells and even cell proliferation was observed after 72 h of incubation. We have obtained satisfactory results, demonstrating that monometallic Au nanowires can be applied in biomedical applications and provide the biocompatibility of bimetallic Au/AgNWs.
- MeSH
- antibakteriální látky farmakologie MeSH
- Escherichia coli MeSH
- lasery MeSH
- lidé MeSH
- naftaleny MeSH
- nanodráty * chemie MeSH
- polyethyleny MeSH
- zlato chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Temporoparietální fasciální laloky (TPFF) se hojně používají ke krytí opěrné kostry při rekonstrukcích ušních boltců. Odběr laloků se většinou provádí otevřenou metodou, která je sice jednodušší, ale často vede ke vzniku nevzhledných jizev a ke ztrátě vlasů. Rádi bychom představili sérii případů, při nichž byla použita technika odběru laloků za asistence endoskopu z jediného kosmeticky přijatelného řezu nad ušním boltcem. Pacienti a metody: Prospektivní studie z období od června 2018 do září 2021 na pacientech, kteří podstoupili jednodobou totální rekonstrukci ušního boltce s použitím autologní kostní chrupavky a porézního polyethylenového (PPE) rámce. Proměnné zahrnují věk, pohlaví, přežití laloku a také vizuální výsledky a komplikace. Výsledky: Celkem bylo odebráno 61 TPFF k zakrytí 15 autologních kostních chrupavek a 46 konstrukcí z PPE u 60 pacientů (jeden pacient byl operován na obou stranách). Odběry TPFF byly provedeny endoskopickou technikou z jednoho ušního řezu. Nebyla zaznamenána žádná nekróza laloku, žádné krvácení a žádný případ nevyžadoval odstranění konstrukce. Pouze u 7/61 (11,5 %) boltců došlo k malému obnažení kostry, které se vyřešilo samo nebo vyžadovalo pouze lokální krytí kožním lalokem, z toho u 3 laloků v důsledku infekce a u 1 laloku došlo k poraněním frontální větve faciálního nervu. Závěr: Jednodobá rekonstrukce ušního boltce je náročná operace, avšak pro malé děti velmi přínosná. Pomocí endoskopické techniky z jedné incize můžeme získat dostatečně velký TPFF s vysokou životaschopností zajišťující plné krytí autologní chrupavčité nebo PPE kostry. Tato metoda je spolehlivá a s pokročilým výcvikem reprodukovatelná. Z přehledu literatury vyplývá, že naše studie je pravděpodobně největší sérií endoskopicky asistovaných odběrů TPFF a první studií, která zavedla endoskopickou techniku s jednou incizí u rekonstrukce ušních boltců.
Introduction: The temporoparietal fascia flaps (TPFF) have been widely used to cover the framework in auricular reconstructions. However, flap harvesting is mostly done by open surgery which may be easier but often results in bad scarring and hair loss. We would like to present a series of cases using endoscopic-assisted flap harvesting techniques with only one single cosmetic auricular incision. Patients and methods: Prospective studies from June 2018 to September 2021 on patients who underwent single-stage total auricular reconstruction using autologous costal cartilage and porous polyethylene (PPE) framework. Variables include age, gender, flap survivability as well as visual results and complications. Results: A total of 61 TPFFs were harvested to cover 15 autologous costal cartilages and 46 PPE frameworks in 60 patients (one patient had operation on both sides). TPFF harvests are performed by endoscopic techniques with one single auricular incision. There was no flap necrosis, no bleeding and no cases required framework removal. Only 7/61 (11.5%) ears had small framework exposure which resolved on their own or only required local skin flap coverage and 1 ear had frontal nerve injury. Conclusion: Single-stage auricular reconstruction is a difficult surgery, yet greatly beneficial to young children. Through a single-incision endoscopic technique, we can obtain sufficiently large high-survivability TPFFs ensuring full coverage of the autologous costal cartilage or PPE framework. This method is reliable, and reproducible with advanced training. After reviewing the literature, we can state that our report probably includes the largest endoscopic-assisted TPFF harvesting series and the first to implement single-incision endoscopic technique in auricular reconstructions.
