126 research outputs found
Custom-made, root-analogue direct laser metal forming implant: a case report.
No full textIn the last few years, the application of digital technology in dentistry has become widespread with the introduction of cone beam computed tomography (CBCT) scan technology, and considerable progress has been made in the development of computer-aided design/ computer-aided manufacturing (CAD/CAM) techniques, including direct laser metal forming (DLMF). DLMF is a technology which allows solids with complex geometry to be produced by annealing metal powder microparticles in a focused laser beam, according to a computer-generated three-dimensional (3D) model. For dental implants, the fabrication process involves the laser-induced fusion of titanium microparticles, in order to build, layer by layer, the desired object. At present, the combined use of CBCT 3D data and CAD/CAM technology makes it possible to manufacture custom-made, root-analogue implants (RAI) with sufficient precision. This report demonstrates the successful clinical use of a custom-made, root-analogue DLMF implant. CBCT images of a non-restorable right maxillary first premolar were acquired and transformed into a 3D model. From this model, a custom-made, root-analogue DLMF implant was fabricated. Immediately after tooth extraction, the RAI with a pre-operatively designed abutment was placed in the extraction socket and restored with a single crown. At the 1-year follow-up examination, the RAI showed a good functional and aesthetic integration. The introduction of DLMF technology signals the start of a new revolutionary era for implant dentistry as its immense potential for producing highly complex macro- and microstructures is receiving vast interest in different medical fields
Valutazione prospettica di 273 impianti con superficie trattata con acidi organici: risultati d 1 a 5 anni
No full textCustom-made laser sintered implant placed in atrophic alveolar ridge: A case report
No full textOBJECTIVES. Modern computerized tomography (CT) acquisition and three dimensional image conversion, combined with the new Direct Laser Metal Forming (DLMF) process, allow the fabrication of custom-made, anatomically-shaped implants. This report demonstrates the successful clinical use of a custom-made, anatomically-shaped DLMF, placed in an extremely atrophic mandibular ridge, characterised by bucco-lingual thickness ATERIALS AND METHODS. CT images of the residual atrophic mandibular ridge were required and modified with specific software into a 3D model. From this model, a custom-made, anatomically-shaped one-piece dental implant was fabricated, with the DLMF technique. The implant RESULTS. After 30 months of functional loading, the implant was well integrated from the functional and aesthetic point of view. CONCLUSIONS. The possibility to fabricate custom-made implants opens new interesting horizons in the sental field
Vertical ridge augmentation of the atrophic posterior mandible with custom-made, computer-aided design/computer-aided manufacturing porous hydroxyapatite scaffolds.
No full textThe present study describes a new protocol for the manufacturing of custom-made hydroxyapatite scaffolds using computer-aided design/computer-aided manufacturing (CAD/CAM), to augment posterior mandibular bone and minimize surgery when severe atrophy is present. Computed tomographic images of an atrophic posterior mandible were acquired and modified into a 3-dimensional (3D) reconstruction model. This model was transferred as a stereolithographic file to a CAD program, where virtual 3D reconstructions of the alveolar ridge were performed, drawing 2 anatomically shaped, custom-made scaffolds. Computer-aided-manufacturing software generated a set of tool-paths for manufacture on a computer-numerical-control milling machine into the exact shape of the 3D projects. Clinically sized, anatomically shaped scaffolds were generated from commercially available porous hydroxyapatite blocks. The custom-made scaffolds well matched the shape of the bone defects and could be easily implanted during surgery. This matching of the shape helped to reduce the time for the operation and contributed to the good healing of the defects. At the 6-month recall, a newly formed and well-integrated bone was observed, completely filling the mandibular posterior defects, and implants were placed, with good primary stability. At the 1-year follow-up examination, the implant-supported restorations showed a good functional and esthetic integration. Although this is an interim report, this study demonstrates that anatomically shaped custom-made scaffolds can be fabricated by combining computed tomographic scans and CAD/CAM techniques. Further studies are needed to confirm these results
Custom-Made Computer-Aided-Design/Computer-Aided-Manufacturing Biphasic Calcium-Phosphate Scaffold for Augmentation of an Atrophic Mandibular Anterior Ridge
No full textThis report documents the clinical, radiographic, and histologic outcome of a custom-made computer-aided-design/computer-aided-manufactured (CAD/CAM) scaffold used for the alveolar ridge augmentation of a severely atrophic anterior mandible. Computed tomographic (CT) images of an atrophic anterior mandible were acquired and modified into a 3-dimensional (3D) reconstruction model; this was transferred to a CAD program, where a custom-made scaffold was designed. CAM software generated a set of tool-paths for the manufacture of the scaffold on a computer-numerical-control milling machine into the exact shape of the 3D design. A custom-made scaffold was milled from a synthetic micromacroporous biphasic calcium phosphate (BCP) block. The scaffold closely matched the shape of the defect: this helped to reduce the time for the surgery and contributed to good healing. One year later, newly formed and well-integrated bone was clinically available, and two implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were placed. The histologic samples retrieved from the implant sites revealed compact mature bone undergoing remodelling, marrow spaces, and newly formed trabecular bone surrounded by residual BCP particles. This study demonstrates that custom-made scaffolds can be fabricated by combining CT scans and CAD/CAM techniques. Further studies on a larger sample of patients are needed to confirm these results
The Role of Fraudulent Transfer Rules in Corporate Insolvency
No full textThe author goes beyond the well-known topic of US-type fraudulent transfer rules as an alternative to the European legal capital rules and deals with the role played in company law by fraudulent transfer provisions and, more generally, by insolvency law rules that work in a functionally comparable way. After an analysis of some tendencies at work especially in Europe the writer puts forward the idea that avoidance is not simply enforcement but expresses - as a substantive law device - an evaluation, not so much of the result of the debtor's behaviour as the debtor's behaviour in itself (and on its "correctness" and/or on its "reasonability"), in order to counterbalance - by virtue of its compulsory nature - company law that is becoming increasingly less mandatory
La revocatoria fallimentare delle attribuzioni indirette
No full textIl libro muove dalla premessa che, al giorno d''oggi, la maggior parte dei pagamenti è mediata da un intermediario, per poi mettere a fuoco la disciplina della revocatoria fallimentare applicabile per il caso in cui il debitore principale o, rispettivamente, l''intermediario fallisca e domandarsi, in ultima analisi: a) chi deve essere il legittimato passivo; b) come si deve atteggiare la prova del danno, e c)
fino a che punto la curatela possa imputare la conoscenza dell''intermediario al destinatario finale della prestazione.
Il lavoro, dopo un ampio capitolo dedicato all''evoluzione della revocatoria fallimentare, si occupa nel cap. II delle intermediazioni realizzate mediante la delegazione, l''espromissione e l''accollo, con riferimento alle quali, non solo si preoccupa di precisare - con la dottrina prevalente - che la prova del danno nella revocatoria si atteggia in maniera molto diversa da quella disciplinata dalla normativa sull''illecito, ma anche - e questa volta in contrasto con la posizione assunta dalla giurisprudenza prevalente - che un conto è provare che
l''atto è pregiudizievole per i creditori ed un altro conto è dimostrare che esso è imputabile al debitore: con importanti conseguenze applicative.
La monografia si sforza di dimostrare poi che una vicenda di intermediazione nei pagamenti si realizza anche mediante talune forme di cessione del credito (cap. V) ed in particolare tutte le volte in cui un intermediario professionale acquista un credito pro-solvendo, dal momento che - quando il cessionario paga nelle mani del cedente il corrispettivo della cessione - è come se si interponesse tra il debitore ceduto ed il cedente; non importa poi se, da un punto di vista strutturale, possa esistere uno scarto temporale o/e quantitativo tra la prestazione del ceduto al cessionario e quella del cessionario al cedente. Con la conseguenza che, sempre secondo questa linea di pensiero, in caso di fallimento del debitore ceduto, la revocatoria fallimentare del pagamento andrebbe indirizzata nei confronti del cedente, come è previsto nell''art. 6 della legge sul factoring (l. 21 febbraio 1991, n. 52) e nell''art. 70, comma 1, della legge fallimentare riformata."The book deals with the regulation concerning preferences in insolvency law
and the effects of these rules on the ever increasing cases where a payment is
mediated by an agent and the debtor or the agent fall into bankruptcy. The work
considers the following questions: a) Who has the action to be brought against?
b) How has the harm to creditors to be demonstrated? c) Can the trustee of the
insolvency proceeding demonstrate that the defendant is knowing the [UTF-8?]debtorâ€TMs
insolvency by demonstrating that the agent is having knowledge of the [UTF-8?]debtorâ€TMs
insolvency? The book containts two chapters devoted to the development of the
regulation concerning preferences in Italy, in the U.S.A. and in Germany. In
chapter 4 it deals with the cases where payments are mediated through a
delegation or an other form of intemediation constitued from the [UTF-8?]debtorâ€TMs side.
Here the work affirms that the demonstration of the harm to creditors has to be
performed differently than in tort law. The work contests also the judiciary
which overlaps the issue of demonstrating the harm to creditors with the
problem concerning the attribuition to the debtor of the payment performed by
the agent. In chapter 5 the book deals with assigments. Here it puts forward
the thesis that, if the assignor gives the assignee the warranty that the
payment will be fulfilled (assignment pro-solvendo) and if the assignee is a
bank or another financial institution, such operation could be regarded
functionally as a form of intermediation. In fact, the debtor transfers the
money to the assignee and the assignee transfers the money to the assignor,
even if such transfers are unlike in consideration, time and ammount.
Consequently, if the debtor falls into bankruptcy, the trustee of the
insolvency proceeding can bring the action against the assignor, as it is laid
down by article 6 of the Italian legge 21 february 1991, n. 52. And as it is
laid down by article 70 (1) of the reformed insolvency law, which was drafted
later than the author had written his doctoral thesis and published the
provisional edition of the present book.
Augmented reality for dental implantology: A pilot clinical report of two cases
No full text© 2019 The Author(s). Background: Despite the limited number of articles dedicated to its use, augmented reality (AR) is an emerging technology that has shown to have increasing applications in multiple different medical sectors. These include, but are not limited to, the Maxillo-facial and Dentistry disciplines of medicine. In these medical specialties, the focus of AR technology is to achieve a more visible surgical field during an operation. Currently, this goal is brought about by an accurate display of either static or dynamic diagnostic images via the use of a visor or specific glasses. The objective of this study is to evaluate the feasibility of using a virtual display for dynamic navigation via AR. The secondary outcome is to evaluate if the use of this technology could affect the accuracy of dynamic navigation. Case presentation: Two patients, both needing implant rehabilitation in the upper premolar area, were treated with flapless surgery. Prior to the procedure itself, the position of the implant was virtually planned and placed for each of the patients using their previous scans. This placement preparation contributed to a dynamic navigation system that was displayed on AR glasses. This, in turn, allowed for the use of a computer-aided/image-guided procedure to occur. Dedicated software for surface superimposition was then used to match the planned position of the implant and the real one obtained from the postoperative scan. Accuracies, using this procedure were evaluated by way of measuring the deviation between real and planned positions of the implants. For both surgeries it was possible to proceed using the AR technology as planned. The deviations for the first implant were 0.53 mm at the entry point and 0.50 mm at the apical point and for the second implant were 0.46 mm at the entry point and 0.48 mm at the apical point. The angular deviations were respectively 3.05° and 2.19°. Conclusions: From the results of this pilot study, it seems that AR can be useful in dental implantology for displaying dynamic navigation systems. While this technology did not seem to noticeably affect the accuracy of the procedure, specific software applications should further optimize the results
Digitally-oriented materials: focus on lithium disilicate ceramics.
No full textThe present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry
Multi-point aerodynamic shape optimization for airfoils and wings at supersonic and subsonic regimes
No full textThe second-generation of supersonic civil transport has to match ambitious targets in terms of noise reduction and efficiency to become economically and environmentally viable. High-fidelity numerical optimization offers a powerful approach to address the complex trade-offs intrinsic to this novel configuration. Past and current research however, despite proving the potential of such design strategy, lacks in deeper insight on final layouts and optimization workflow challenges. Stemming from the necessity to quantify and exploit the potential of modern design tools applied to supersonic aircraft design, this work partially fills the gap in previous research by investigating RANS-based aerodynamicoptimization for both supersonic, transonic and subsonic conditions. The investigation is carried out with the state-of-the-art, gradient-based MDO framework \textit{MACH}, developed at University of Michigan's MDO Lab - which hosted the author for the 14-month research stint. Details of the tool and a brief overview of supersonic aircraft design and modern aerodynamic optimization strategies are reported in the first part of this manuscript.After circumscribing the research niche, I perform single and multi-point optimization to minimize the drag over an ideal supersonic aircraft flight envelope and assess the influence of physical and numerical parameters on optimization accuracy and reliability. Leading and trailing edge morphing capabilities are introduced to improve the efficiency at transonic and subsonic flight speed by relaxing the trade-offs on clean shape optimization. Benefits in terms of drag reduction are quantified and benchmarked with fixed-edges results. It is observed how the optimized airfoils outperform baseline reference shapes from a minimum of 4\% up to 86\% for different design cases and flightconditions. The study is then extended to the optimization of a planar, low-aspect-ratio, and low-sweep wing, using the same schematic approach of 2D analysis. I investigate the influence of wing twist alone and twist and shape on cruise performance, obtaining a drag reduction of 6\% and 25\% respectively as the optimizer copes with both viscosity and compressibility effects over the wing. Results for 3D multi-point optimization suggest that the proposed strategy enables a fast and effective design of highly-efficient wings, with drag reduction ranging from a minimum of 24\% up to 74\% for cruise at different speeds and altitudes, including edge deflection. Ultimately, this work provides an extensive and, to the best of author knowledge, unprecedented insight on the optimal design solutions for this specific aircraft configuration and the challenges of the optimization framework. The benefits of RANS-based aerodynamic shape optimization to capture non-intuitive design trade-offs and offer deeper physical insight are ultimately discussed and quantified. Given the promising results in terms of performance improvements and design efficiency, it is hoped that this work will foster the implementation of this method for more comprehensive full-configuration, multidisciplinary supersonic aircraft optimization studies.Aerospace Engineerin
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