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Obstructive sleep apnoea syndrome is characterized by an obstruction in the upper airway due to the pharyngeal collapse during sleep. Mandibular advancement devices have gained success and large popularity as a non-invasive treatment for OSAS. Nevertheless, the effects of mandibular advancement devices were poorly investigated in literature. To this aim the paper proposes a procedure to achieve a numerical simulation model useful to assess the stress/strain distribution on the temporomandibular joint and periodontal ligaments caused by the mandibular advancement. The findings suggest that the mandibular roto-translation induced by the MAD provoke high stress on the molars and premolar teeth.

This study defines a methodological procedure for the design and manufacturing of a prosthetic implant for the reconstruction of a midsagittal bony-deficiency of the skull due to the Apert congenital disorder. Conventional techniques for craniofacial defects reconstruction rely on the mirrored-image technique. When the cranial lesion extends over the midline or in case of bilateral defects, other approaches based on thin plate spline interpolation or constrained anatomical deformation are applied.The proposed method uses the anthropometric theory of cranial landmarks identification for the retrieval of a template healthy skull, useful as a guide in the successive implant design. Then, anatomical deformation of the region of interest and free-form modelling allow to get the customized shape of the implant. A full bulk and a porous implant have been provided according to the surgeon advises.The models have been 3D printed for a pre-surgical analysis and further treatment plan. They fulfilled the expectancies of the surgeon thus positive results are predictable.This methodology results to be reproducible to any other craniofacial defect spanning over the entire skull.

PurposeOrbital fractures are the most commonly encountered midfacial fractures, and usually, the fracture involves the floor and/or the medial wall of the orbit. This paper aims to present an innovative approach for primary and secondary reconstructions of fractured orbital walls through the use of computer-assisted techniques and additive manufacturing.Design/methodology/approachFirst, through the 3D anatomical modelling, the geometry of the implant is shaped to fill the orbital defect and recover the facial symmetry. Subsequently, starting from the modelled implant, a customised mould is designed taking into account medical and technological requirements.FindingsThe selective laser sintered mould is able to model and form several kind of prosthetic materials (e.g. titanium meshes and demineralised bone tissue), resulting in customised implants and allowing accurate orbital cavity reconstructions. The case study proved that this procedure, at the same time, reduces the morbidity on the patients, the duration of surgery and the related costs.Originality/valueThis innovative approach has great potential, as it is an easy and in-office procedure, and it offers several advantages over other existing methods.

Obstructive sleep apnea syndrome (OSAS) is a sleep disorder that causes pauses in breathing or periods of shallow breathing during sleep. Mandibular advancement devices (MADs) represent a non-invasive treatment for OSAS that has had the highest development in recent years. Nevertheless, literature has not primarily investigated the effects of mandibular advancement. This paper presents a finite element method numerical simulation model for evaluating the stress/strain distribution on the temporomandibular joint (TMJ) and periodontal ligaments caused by advancement devices used for the treatment of OSAS. Results highlight that the mandible lift phase generates significant stress values on TMJ, which cannot be neglected for extended usage of MADs. Furthermore, mandible molar teeth are more loaded than incisor ones.

This paper presents a methodological procedure, based on the anatomical reconstruction and constrained deformation, to design custom-made implants for forehead augmentation in people affected by Apert syndrome, experiencing a frontal bone deficiency. According to the anthropometric theory, a cranial landmarks identification procedure was applied to retrieve, from a repository, a healthy skull, used as reference geometry for implant modelling. Then, using constrained deformation and free-form modelling techniques, it was possible to design a patient-specific implant. At last, the implant was realised using a custom mould, specially designed according to the patient’s needs to provide an accurate fit of the defect site. The design procedure was tested on a patient suffering from Apert syndrome. Three implants were virtually modelled and 3D-printed for pre-surgical evaluation. Their shapes were 3D compared with a reference one (handcrafted by a surgeon) to test the accuracy. Deviations are negligible, and the customised implant fulfilled the surgeon’s requirements.

Electromagnetic shielding and propagation in concrete structures are getting more and more interest in radiation hazard problems and wireless communications. The protection of sensitive environment is nowadays carried out by appropriate shielding room made of metallic walls. Their efficacy is counteracted by their heaviness, not adequate for the installation over existing building walls. The using of concrete composites filled by conductive elements represents a valid alternative to metallic shielded room since they can be adopted to directly build up the building walls and/or to easily plaster existing walls. Graphene oxide powder and metallic fibers are being currently investigated as fillers in the manufacturing of electromagnetic shielding cementitious composites. The novelty of the present work is the characterization of a multi-reinforced cement realized by combining such two filler typologies: the synergistic effects of graphene oxide microparticles and short steel fibers result in enhancement of both mechanical properties and EMI effectiveness of the cementitious composites.

Carbon-based fillers from industrial wastes and commercial ones were compared to improve the properties of lime-based mixes. As commercial fillers, graphene nanoplatelets and activated carbon were used, whereas as industrial wastes a char obtained by the gasification of biomasses and a used foundry sand were chosen. Carbon-based wastes were found to be a good cost-effective alternative to commercial carbon based fillers to increase the compressive strength (of about 25%) and to reduce water capillary absorption (of about 50%) thanks to the paste refinement; to enhance depollution capacity (of about 25%) and increase both electrical conductivity (up to 65%) and electromagnetic shielding effectiveness (of about 6%) of the hardened compounds thanks to the carbon content.

Carbon nanotube reinforced concrete composites (RCC) were characterized in microwave bands currently employed in wireless telecommunication systems. Dielectric permittivity was retrieved by waveguide method and adopted to compute shielding effectiveness of RCC structures having different thickness/filler content. The shielding was also evaluated by reverberation chamber set up; theoretical calculations and measured values are in close agreement, thus testifying to the procedure reliability. Finally, a frequency selective absorber made of RCC layers was designed with the aid of a numerical optimization tool (particle swarm algorithm); the discussion of results is supported by a finite element method analysis of the layered structure.

In this study wood processing by-products were used by replacing natural sand for producing lightweight mortars. Manufacturers of wood products and furniture generate sawdust and pieces of side-cuts from a log to rectangular shapes. These are also produced by cutting, drilling, and milling operations when a wood piece is cut either from wood logs or while preparing finished products. Saw dust is often collected in filter bags or dust collectors. Three different percentages of substitution of natural sand were tried: 2.5%, 5%, and 10% by volume of the sand. Wood by-products were always pre-soaked in water and sometimes in calcium hydroxide aqueous solution in order to obtain wood mineralization before addition to the mortar mixture. Mortars containing wood by-products were characterized by means of compression and bending tests, drying shrinkage, resistance to water vapour permeability, water capillary absorption, and thermal conductivity measurements. Results obtained showed that a maximum dosage of 5% wood by-products should be used in order to avoid an excessive loss of mortar mechanical strength, and due to the reduction of thermal conductivity of about 25%. On the other hand, if a water reducing admixture is added, adequate mechanical performance can be obtained even with 10% wood by-products.

Already from the beginning, 50 years ago, the first nucleus of researchers establishing the research group, was convinced that the construction sector was the best option for the valorization of industrial by-products as “secondary raw materials”. In fact, this sector is probably the largest consumer of resources and the largest waste generator, consequently it has huge environmental impact. On the other hand, construction materials affect the performance of buildings with respect to safety, health, environmental performance and energy efficiency. Manufacturing of construction products using alternative raw materials; recycling to manage construction and demolition waste; durability and environmental compatibility of materials: all these were the different and challenging fields of research that the group has faced in a continuous effort of innovation and cooperation at national and international level. The focus of the group was already perfectly in line with what is now called “Circular Economy”, which at present is considered a revolution in the way of human economic development. We are sure the group thus contributed to this revolution even before the term was in current use. We feel ready for the next 50.

The paper aims to evaluate the effects caused by a Mandibular Advancement Device (MAD) for Obstructive Sleep Apnoea Syndrome (OSAS) treatment. This study is based on Finite Element Method (FEM) for evaluating the load distribution on temporomandibular joint, especially on the mandibular condyle and disc, and on periodontal ligaments. The stress values on condyle and periodontal ligaments lead authors to consider MAD a safe procedure even for a long period. The obtained results also show the relationship between MAD material and load distribution at the periodontal ligaments. The paper is a step toward future analyses for studying and comparing the effects of MAD features, such as material, shape and dimensions, in order to allow the clinician prescribing the most fitting device.

Cracking of concrete due to early-age shrinkage is a common problem that generally leads to several problems experienced by concrete structures, mainly influencing and reducing durability and lifetime. This is of particular relevance in the case of slabs type structures such as pavements, industrial floors, bridge decks, tunnel lining and precast elements, that show much larger surface areas compared with other kinds of structural components, such as beams and columns. In addition, the cracks allow water and other chemical agents to penetrate into concrete and get in touch with steel reinforcements, leading to reinforcement corrosion, even to breakage. Consequently, curing is the unique traditional method to avoid such problems. However, in certain applications, due to the severe environmental conditions and/or due to the actual dimensions of structural elements, curing does not fit the purpose in the prevention of cracks. For the above said, fibers have been incorporated in concrete to reduce and/or prevent the propagation of the early-age-shrinkage cracking. In fact, the utilization of fibers has increased progressively over the past years in structural applications. The present paper focuses on early-age shrinkage cracking with a special attention given to new concretes aiming at reduced shrinkage phenomena through the addition of different types of macro fibers within the cement matrix. In order to estimate the effectiveness in preventing the growth of the cracks, an easy methodology, based on image analysis (IA), has been developed. The results show different considerations regarding distinct materials: in terms of the effectiveness of fibers, the addition of polypropylene and polyethylene macro fibers exhibits the best performance and leads to a certain delay and a wide decreasing in cracking formation. The use of fibers has been found to be very effective in the width reduction of the cracks and, even if not so significantly, in the length reduction.

The paper represents the “state of the art” on sustainability in construction materials. In Part 1 of the paper, issues related to production, microstructures, chemical nature, engineering properties, and durability of mixtures based on binders alternative to Portland cement were presented. This second part of the paper concerns the use of traditional and innovative Portland-free lime-based mortars in the conservation of cultural heritage, and the recycling and management of wastes to reduce consumption of natural resources in the production of construction materials. The latter is one of the main concerns in terms of sustainability since nowadays more than 75% of wastes are disposed of in landfills.

This review presents “a state of the art” report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1—the present paper—focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.

Purpose – The purpose of this study is to show how selective laser sintering (SLS) manufacturing of bioresorbable scaffolds is used for applications in bone tissue engineering. Design/methodology/approach – Polycaprolactone (PCL) scaffolds were computationally designed and then fabricated via SLS for applications in bone and cartilage repair. Findings – Preliminary biocompatibility data were acquired using human mesenchymal stem cells (hMSCs) assuring a satisfactory scaffold colonization by hMSCs. Originality/value – A promising procedure for producing porous scaffolds for the repair of skeletal defects, in tissue engineering applications, was developed.

Diagnosis and treatment of orbital wall fractures are based on both physical examination and computed tomography scan of the orbital cavity. The present paper reports on the secondary reconstruction of the skeletal orbit following untreated orbital floor fracture in a patient wearing an ocular prosthesis because of an orbital trauma. A computer-assisted approach, based on anatomical modelling and custom-made mould fabrication via selective laser sintering, is proposed for manufacturing a preformed orbital implant. Such a procedure offers precise and predictable results for orbital reconstructions. This protocol proved an effective reduction of operating time, patient morbidity and a fast and low-cost preoperative planning procedure. Such an approach can be used for immediate and in-office manufacturing of custom implants in trauma and reconstructive patients.

The main limitations connected to the traditional diagnostic techniques of imaging in orthodontics are that they offer a 2D representation of 3D structures. Given that facial harmony has become one of the main objectives of orthodontic treatment, the aim of the present study was to propose a 3D cephalometric evaluation of the soft tissues of the face. Carrying out the same 3D aesthetic analysis, at the beginning and end of clinical treatment, it is possible to collect information about the influence of orthodontic displacement on the proportions between the diverse areas of the profile.

Selective laser sintering (SLS) is a solid freeform fabrication technique, developed by Carl Deckard for his master's thesis at the University of Texas, patented in 1989. SLS manufacturing is a technique that produces physical models through a selective solidification of a variety of fine powders. SLS technology is getting a great amount of attention in the clinical field. In this paper the characteristics features of SLS and the materials that have been developed for are reviewed together with a discussion on the principles of the above-mentioned manufacturing technique. The applications of SLS in tissue engineering, and at-large in the biomedical field, are reviewed and discussed.

The shielding performance of random concrete composite samples are checked under a random excitation. It is achieved by means of a nested reverberation chamber system. Metallic fibers are randomly diffused in the concrete in order to improve shielding effectiveness from less than 10 dB up to an averaged value of 35 dB within a frequency range that includes communication system operating bands.

Exposure to wood dust is a common occurrence in all countries and may cause various diseases such as allergic rhinitis, chronic bronchitis, and asthma. Moreover, the International Agency for the Research on Cancer (IARC) in 1995 classified the hardwood dust as a carcinogen agent to humans. For the above reasons dust management strategies in industrial environment, especially of airborne dust, are strongly required. In this study, we propose the use of Scanning Electron Microscopy (SEM) and ImageJ processing program in order to evaluate the morphology of the particles and measure the particle size and size distribution of sanding airborne dust from seven diverse soft-, hard- and tropical hardwood. Such a method shows a great potential to be considered as a standardized method of measurement and analysis in order to characterize the grain size and size distribution of wood particles before carrying out any toxicological tests.

In the present paper an investigation of mechanical behaviour and thermal conductivity of a lightened building material containing either styrene butadiene rubber (SBR) or polyurethane (PU) waste particles or scraps coming from wasted rubber-shoe outsoles (SR, acronym of ‘sole rubber’) is presented. Several mortar mixtures were prepared by replacing quartz sand with 0%, 10%, and 30% of either SBR or PU or SR waste particles. The influence of rubber particle addition on fresh mortar behaviour, compressive and flexural strength of mortar as well as on mortar thermal conductivity was detected. An optimization of mortar mixture proportions was carried out by adding a limestone powder as filler. The experimental investigation showed that the addition of rubber particles reduces both the material unit weight and the thermal conductivity. The thermal insulating effect of rubber particles indicates a high and promising potential for future developments. On the other hand, the addition of limestone powder produced higher thermal conductivity as well as higher compressive and flexural strength.

In the present paper an investigation of mechanical behaviour and thermal conductivity of a lightweight building material containing either styrene butadiene rubber (SBR) or polyurethane (PU) waste particles is presented. Several mortar mixtures were prepared by replacing quartz sand with 0, 10 and 30% of either SBR or PU post-consumer plastics particles. The influence of rubber particle addition on fresh mortar behaviour, compressive and flexural strength of mortar as well as on mortar thermal conductivity was investigated. An optimization of mortar mixture proportions was carried out by adding a limestone powder as filler. The experimental investigation showed that the addition of rubber particles reduces both the material unit weight and the thermal conductivity. The thermal insulating effect of rubber particles indicates a promising potential for future developments. On the other hand, the addition of limestone powder produced higher thermal conductivity as well as higher compressive and flexural strength.

Solid free-form fabrication (SFF) techniques use layer-based manufacturing to create physical objects directly from computer-generated models. Using an additive approach to manufacture shapes, SFF systems join liquid, powder or sheet materials. Selective laser sintering (SLS) is a SFF technique by which parts are built layer-by-layer offering the key advantage of the direct manufacturing of functional parts. In SLS, a laser beam is traced over the surface of a tightly compacted powder made of thermoplastic material. In this paper is characterized a new aluminum-filled polyamide powder developed for applications in SLS. This material is promising for many applications that require a metallic look of the part, good finishing properties, high stiffness and higher part quality.

The waste management of glass fiber reinforced polymer (GRP) materials, in particular those made with thermosetting resins, is a critical issue for the composites industry because these materials cannot be reprocessed. Therefore, most thermosetting GRP waste is presently sent to landfill, in spite of the significant environmental impact caused by their disposal in this way. The limited GRP waste recycling worldwide is mostly due to its intrinsic thermosetting properties, lack of characterization data and unavailability of viable recycling and recovery routes. One of the possibility for re-using GRP industrial by-product is in form of powder as a partial aggregate replacement or filler addition in cement based composites for applications in sustainable construction materials and technologies. However, the feasibility of this kind of reutilization strongly depends on the morphology and particle size distribution of a powder made up of polymer granules and glass fibers. In the present study, the use of image analysis method, based on scanning electron microscopy (SEM) and ImageJ processing program, is proposed in order to evaluate the morphology of the particles and measure the particle size and size distribution of fine GRP waste powder. The obtained results show a great potential of such a method in order to be considered as a standardized method of measurement and analysis in order to characterize the grain size and size distribution of GRP particles before exploiting any compatibility issue for its recycling management.

Objective: To evaluate volumetric variations in the palate following rapid expansion, both immediately after treatment and over time. Materials and Methods: The sample was composed of 30 patients in early mixed dentition treated with a Haas-type device cemented onto the primary second molars. The mean age of the patients upon commencement of expansion was 7 years and 6 months (standard deviation [SD], 12 months). Measurement of palatal volume was conducted via 3D acquisition of plaster models using laser scanning before treatment (T1), upon device removal (T2), and 2.6 years afterward (T3). Results: The volume of the palate increased in a statistically significant fashion from T1 to T2 and from T1 to T3, and it decreased in a nonsignificant fashion from T2 to T3. Conclusions: Palatal volume significantly increases with rapid maxillary expansion (RME) treatment with insignificant relapse. The use of virtual 3D models with the aid of Apposite software permits evaluation of the morphologic and volumetric changes induced by orthodontic treatment.

To investigate the short-term optical, chemical and morphological changes in Invisalign appliances.One 'as-received' Invisalign aligner, one 'as-received' Invisalign aligner immersed in artificial saliva for 14 days and 10 Invisalign aligners worn by 10 randomly selected patients for 14 days were used. Fourier'transform infra-red microspectroscopy was used to characterise any molecular changes on the surfaces of the appliances, spectrophotometry was used to evaluate any changes in colour and transparency, scanning electron microscopy and energy dispersive X-ray microanalysis were used to examine the surface morphology and elemental composition of deposits on the surfaces of the aligners and gas chromatography-mass spectrometry was used to identify substances released from the aligners into the artificial saliva.Aligners worn for 14 days had microcracks, abraded and delaminated areas, localised calcified biofilm deposits and loss of transparency. Monomers and/or by-products were not released from the aligner suspended in artificial saliva for 14 days, which suggests that the material is chemically stable.Further studies are required to evaluate how intra-oral conditions may influence the optical properties and chemical stability of the aligners.

In this work, the shielding effectiveness (SE) of a densified-small-particles (DSP) cement composite, with different loading particles embedded in, has been investigated through the nested reverberation chamber facility. Particular effort has been spent in characterizing the SE behavior with the increasing drying and in improving the experimental practice to solve out previously faced measurement troubles. Findings are of interest in architectural shielding, microwave spectroscopy and investigation of physical-chemical properties of DSP materials.

The early detection of cutaneous pigmented lesions is an important aid to the clinician in recognizing malignant melanoma. In an attempt to correlate the depth of a pigmented skin lesion with its malignant potential, phantoms able to simulate the diffuse reflectance of some lesions of different thicknesses were manufactured and tested to validate a diagnostic instrument developed in-house. Such optical skin-tissue phantoms may be useful for accelerating and optimizing the diagnosis of suspicious lesions of the skin. In fact, benign melanocytic lesions are different in terms of their diffuse reflectance from melanoma. The diffuse reflectance of pigmented skin lesions depends on the amount and distribution of the absorbing/diffusing chromophores embedded in the skin layers. The basic phantom material is a PVA hydrogel in which appropriate amounts of optical scatter are added extraneously at the time of formation to achieve tunability of the optical properties. Liquid Indian ink is used to simulate melanin and all the other chromophores. Slabs were prepared to mimic lesions of different depths. The optical properties of the tissue phantoms were determined in the visible and near-infrared spectral ranges using a noninvasive instrument made from a purpose-modified digital camera. The measured reflectance was correlated with the depth of the lesion both in a Monte Carlo simulation environment and in a laboratory experiment.

This paper presents a shielding effectiveness evaluation of densified with small particle (DSP) cement composite at microwave frequencies by means of an improved nested reverberation chamber (NRC) technique, more faster than the classical one. In fact, the mechanical stirring inside the inner chamber was replaced by the frequency stirring method (FS) and only one scattering parameter was acquired to estimate both empty and loaded aperture. By this method, the stirrer movement becomes unnecessary. A software was used to manage the measurement and the post-processing operations.

Repairing critical human skull injuries requires the production and use of customized cranial implants and involves the integration of computer aided design and manufacturing (CAD and CAM). The main causes for large cranial defects are trauma, cranial tumors, infected craniotomy bone flaps and external neurosurgical decompression. The success of reconstructive cranial surgery depends upon: the preoperative evaluation of the defect, the design and manufacturing of the implant, and the skill of the operating surgeon. Cranial implant design is usually carried out manually using CAD although this process is very time-consuming and the quality of the end product depends wholly upon the skill of the operator. This paper presents an alternative automated method for the design of custom-made cranial plates in a PHANToM®-based haptic environment, and their direct fabrication in biocompatible metal using electron beam melting (EBM) technology.

Quality of service, in terms of improvement in patient satisfaction, is an increasingly important objective in all medical fields, and is especially imperative in orthodontics due to the high numbers of patients treated. Information technology can provide a meaningful contribution to bettering treatment processes, and we maintain that systems such as CAD, CAM and CAE, although initially conceived for industrial purposes, should be evaluated, studied and customized with a view to use in medicine. The present study aims to evaluate Reverse Engineering (RE) and Rapid Prototyping (RP) in order to define an ideal chain of advanced technological solutions to support the critical processes of orthodontic activity.