Search results for " Loos"
showing 10 items of 15 documents
Maxillary Implant-Supported Overdentures: Mechanical Behavior Comparing Individual Axial and Bar Retention Systems. A Cohort Study of Edentulous Pati…
2020
Background and objectives: To compare the medium- to long-term mechanical behavior of overdentures with two different retention systems: overdentures with Locator®
The effects of metal implants on inflammatory and healing processes
2007
Abstract Metal implants are known for their superior mechanical properties. However, cases of implant failure mainly due to aseptic loosening do occur. The formation of particulate wear debris and corrosion products, such as metal ions and reactive oxygen species, are considered to be crucial factors leading to the failure of metal implants. These metal degradation and corrosion products can induce inflammatory responses, mediated among others by neutrophils, macrophages and endothelial cells. Furthermore, these degradation products may affect blood vessel formation, one of the central processes in wound healing after implantation. Such events can lead to the aseptic loosening of implants c…
A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns
2020
This study aimed to analyze a novel technique to make screws with greater untightening resistance and to solve screw loosening in implant-supported single crowns. Thirty grade IV titanium straight abutments were screwed onto 30 external hex implants using grade IV titanium screws (30 Ncm). They were exposed to cyclic loading (300,000 cycles, 200 N). Samples were divided into 4 groups (15 samples per group): new screws (SCREW group) (control), reused screws (rSCREW group), new screws wrapped with polytetrafluoroethylene (PTFE) tape (PTFE group), and reused screws wrapped with PTFE tape (rPTFE group). Reverse torque values (RTVs) were recorded with a digitally calibrated implant motor. Mean R…
Preload loss of abutment screws after dynamic fatigue in single implant-supported restorations. A systematic review
2017
Background To carry out a systematic literature review of the causes of preload loss of the abutment screws, of internal and external connection implants, tightened to different torque values and subjected to cyclic loading. Material and methods A systematic search was conducted in PubMed, EMBASE, and Cochrane Library databases with reference to in vitro studies in which internal and external connection implants were subjected to cyclic loads to determine the degree of loosening of the abutment screws after loading. Results The reviewed studies tested distinct implant connections (mostly externally hexed, and morse taper) subjected to diverse cycles (from 16667 to 1 million), with loads ran…
Mechanisms of Disease: molecular insights into aseptic loosening of orthopedic implants
2007
Despite the success of treating rheumatic disorders with biologic therapies, joint replacement surgery still remains the final treatment option in many cases. Approximately 1.5 million joint arthroplastic operations are performed annually worldwide. Implant failure due to massive bone loss and aseptic loosening of prostheses, however, is a major complication of joint replacement, which can lead to high socioeconomic burdens both for the individual patient and for health-care systems. To date, there is no approved drug therapy to prevent or inhibit periprosthetic osteolysis, and aseptic loosening of prostheses can only be overcome by surgical revision. Research during the past decade, howeve…
Thermal Parameters Measurements of High-Rise Building Envelope
2016
In buildings, to ensure the thermal comfort of the occupants and to keep the energy consumption as low as possible, a correct design of the thermal system is necessary. To do so, an appropriate determination of the thermo-physical properties of the wall materials is needed, particularly; new light-weight building technologies are widely used in the construction of the building envelope. One of these parameters, particularly important in Mediterranean climatic dynamic conditions is the heat capacity, due to the presence of the sun’s energy contribution in hot and cold seasons. The value of the heat capacity in such like materials is typically quite different from the declared parameter, obta…
Ornamento criminale. La lezione di Louis H. Sullivan, John W. Root e Adolf Loos
2015
Nell’età contemporanea in cui l’architettura tende spesso alla ricerca della spettacolarità e a creare forme in cui la destinazione d’uso si annulla in un’esperienza estetica, la questione dell’ornamento torna a essere centrale nel dibattito filosofico e architettonico. Di contro, le problematiche legate all’ecologia e al paesaggio pongono sempre più insistentemente l’accento su un’etica della responsabilità che condanna i “crimini” di un’estetica disinteressata al rispetto dell’ambiente. Alla luce di queste coordinate può essere utile riprendere le riflessioni di quei teorici, come Louis H. Sullivan, John W. Root e Adolf Loos, che tra Ottocento e Novecento hanno dichiarato in modo esplicit…
The Role of Oxidative Stress in the Response of Endothelial Cells to Metals
2012
The involvement of endothelial cells in inflammation and blood vessel formation (angiogenesis) makes them important for the integration of metal implants. Metal degradation products can, however, influence these processes, possibly leading to ineffective wound healing, prolonged inflammation and eventually aseptic loosening of the implant. Different metal degradation processes have been shown to lead to ROS formation. Oxidative stress, therefore, can mediate the reactions of the human body to the implant. While the response of endothelial cells to oxidative stress has been well studied, the effects of ROS produced as the result of metal degradation have not been addressed as yet. Therefore,…
Il grado zero dell'abitare
2022
In un racconto del 1977 dal titolo Terapia Intensiva, James G. Ballard profeticamente anticipa una società che vive in un lockdown estremo: si vive sempre in casa e, di conseguenza, le relazioni sono esclusivamente telematiche. L’incontro fisico che, ad un certo punto avviene tra i personaggi della storia, diventa traumatico e si conclude tragicamente. Notoriamente la condizione pandemica ci ha costretto ad una simile implosione domestica. Ma, paradossalmente, il massimo dell’abitare domestico diventa il suo minimo, si risolve in un non-abitare, una sorta di grado zero dell’abitare. In a 1977 story titled Intensive Care, James G. Ballard prophetically anticipates a society that lives in an …
Investigating the Multi-Recyclability of Recycled Plastic-Modified Asphalt Mixtures
2023
Although the benefits of asphalt recycling have been scientifically proven and several best practices are being implemented, further research is required in specific and specialized areas. One of these circumstances is the recycling of Reclaimed Asphalt Pavements (RAPs) that contain asphalt modifiers such as elastomers and/or plastomers. Following the principles of the circular economy and considering the sustainability implications of asphalt mixtures, this paper deals with the multi-recyclability of asphalt mixtures containing 50% RAP with and without a recycled plastic asphalt modifier and rejuvenating agent. The recycled plastic asphalt modifier was made of hard recycled plastics and wa…