Prosthesis — Open Access Journal

Mitral regurgitation imposes a significant symptomatic burden on patients who are not candidates for conventional surgery. For these patients, transcatheter repair and replacement devices are emerging as alternative options. One such device is an intravalvular balloon or spacer that is inserted between the mitral valve leaflets to fill the gap that gives rise to mitral regurgitation. In this study, we apply a large-deformation fluid-structure interaction analysis to a fully 3D subject-specific mitral valve model to assess the efficacy of the intra-valvular spacer for reducing mitral regurgitation severity. The model includes a topologically 3D subvalvular apparatus with unprecedented detail. Results show that device fixation and anchoring at the location of the subject’s regurgitant orifice is imperative for optimal reduction of mitral regurgitation. Full article

Rehabilitation of atrophic maxilla still remains a challenge. Fixed implant-supported restorations have become more predictable in the last years; nevertheless, technical and biological complications still occur. Removable overdenture fully supported by a CAD/CAM titanium bar seems to be a viable treatment option for the rehabilitation of completely edentulous patients with a high degree of bone resorption. In these clinical cases, the soft tissues of the lower third of the face need to be respected, and a fixed-removable solution is the only option to have good hygiene control. Nevertheless, there is no consensus about the optimal number and position of the implants. A total of six adult patients were recruited and treated with an overdenture fully supported by a CAD/CAM titanium bar and low-profile attachment, screwed on four or six implants. A detailed step-by-step description of the procedures was presented. Overall, all the patients were successful treated with no relevant complications. With the limitations of this case series, maxillary implant overdenture fully supported by four or six implants seems to be a safer treatment option for the minimally invasive rehabilitation of atrophic maxillae, regardless of the number of implants. Full article

(1) Background: To mitigate the shortage of respiratory devices during the Covid-19 epidemic, dental professional volunteers can contribute to create printed plastic valves, adapting the dental digital workflow and converting snorkeling masks in emergency CPAP (continuous positive airways pressure) devices. The objective of this report was to provide the specific settings to optimize printing with the 3D printers of the dental industry. (2) Methods: In order to provide comprehensive technical notes to volunteer dental professionals interested in printing Charlotte and Dave connectors to breathing devices, the entire digital workflow is reported. (3) Results: The present paper introduces an alternative use of the dental Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) machinery, and reports on the fabrication of a 3D printed connection prototypes suitable for connection to face masks, thereby demonstrating the feasibility of this application. (4) Conclusions: This call for action was addressed to dentists and dental laboratories who are willing to making available their experience, facilities and machinery for the benefit of patients, even way beyond dentistry. Full article

Obstruction of the left ventricular outflow tract (LVOT) is a common complication of transcatheter mitral valve replacement (TMVR). This procedure can determine an elongation of an LVOT (namely, the neo-LVOT), ultimately portending hemodynamic impairment and patient death. This study aimed to understand the biomechanical implications of LVOT obstruction in a patient who underwent TMVR using a transcatheter heart valve (THV) to repair a failed bioprosthetic heart valve. We first reconstructed the heart anatomy and the bioprosthetic heart valve to virtually implant a computer-aided-design (CAD) model of THV and evaluate the neo-LVOT area. A numerical simulation of THV deployment was then developed to assess the anchorage of the THV to the bioprosthetic heart valve as well as the resulting Von Mises stress at the mitral annulus and the contract pressure among implanted bioprostheses. Quantification of neo-LVOT and THV deployment may facilitate more accurate predictions of the LVOT obstruction in TMVR and help clinicians in the optimal choice of the THV size. Full article

The study presented in this paper details the development and experimental testing of a novel, magnetic, tactile feedback device that is able to deliver a stimulus to a patch of skin on the lower arm of a user. The device utilizes magnets to deliver a sensation that is not dependent on controlling specific frequency bands to stimulate the mechanoreceptors, as is the case with vibro-tactile methods. The device was tested on human volunteers to evaluate its ability to induce a response from the user through the magnetic interface. The study aims to quantify the ability of the user to sense the stimulus by analysis of the receiver operating characteristic (ROC) and delay in response under different experimental conditions. Three different speeds and two different distances were explored for the magnetic interface. A two-way, repeated-measures ANOVA with post-hoc analysis was performed for the percentage of correct responses, delay in response time, and area under the curve (AUC) of the obtained ROCs. The results showed that the different conditions had a significant effect on the number of correct responses and the AUC, but not on the delay. The magnetic interface thus needs to be optimized across different parameters to deliver the best detectable stimulus to the user. Future work includes further development of the device and working towards a comparative trial with other tactile feedback approaches. Full article

This case study concerns a patient who had lost all of his teeth, needing a rehabilitation with total prosthesis, who went to the dentist looking for help to overcome psycho-physical trauma and to overcome functional and social problems related to being a prosthesis wearer. Tooth loss occurs most in old age, even if it is not a direct consequence of aging. The rehabilitation of oral functions allows the patient to speak, chew, smile and feel confident in his own aesthetics and therefore improve, even a lot, his well-being in social relations. It is very important in oral rehabilitations to evaluate their type and therapeutic timing. This study stems from the idealization of a new protocol to simplify the supported oral rehabilitations. In this manuscript, a patient was considered and shown according to a complete photographical documentation all the phases. Rehabilitation included the use of Osstem (Osstem, Seoul, Korea) and equator type abutments (Rhein83, Bologna, Italy). This manuscript claims to represent the first of a whole series of cases demonstrating the utility of this protocol. Full article

The developments in the field of rehabilitation are proceeding hand in hand with those of cybernetics, with the result of obtaining increasingly performing prostheses and rehabilitations for patients. The purpose of this work is to make a brief exposition of new technologies regarding composites materials that are used in the prosthetic and rehabilitative fields. Data collection took place on scientific databases, limited to a collection of data for the last five years, in order to present news on the innovative and actual materials. The results show that some of the most commonly used last materials are glass fibers and carbon fibers. Even in the robotics field, materials of this type are beginning to be used, thanks above all to the mechanical performances they offer. Surely these new materials, which offer characteristics similar to those in humans, could favor both the rehabilitation times of our patients, and also a better quality of life. Full article

This article reports the case of a patient suffering from Alzheimer’s disease who underwent a dental procedure for the peri-implantitis of his dental implants placed some years earlier. Our aim was to describe a misinterpreted accidental foreign body aspiration and its management. Due to an involuntary movement, the patient accidentally ingested a screwdriver, so, although asymptomatic, he was taken to the hospital. Based on the radiographic interpretation, the radiologists diagnosed the presence of the object in the distal esophagus; an esophagogastroduodenoscopy was performed but the screwdriver was not found. Subsequently, a computed tomography (CT) scan was performed which placed the foreign body in the airways and it was successfully removed by bronchoscopy. Patients with dementia need additional care during dental procedures because of the increased risk of ingestion and/or aspiration. We demonstrated how important it is, even without any symptoms, the need to be vigilant in seeking out urgent care as soon as possible. Full article

In recent years, a major research goal of companies has been to create mechanical components suitable for rehabilitation that are safer and more reliable. Evaluating their biomechanical features could be a way to improve them. The purpose of this study was to evaluate the different biomechanical features of low-profile retentive systems (Rhein®). Two different attachment systems were tested: OT Equator® Smart Box and Locator® R-TX. Once a machine was created for the simulation of the connection and disconnection of the attacks in a combined manner, it was possible to evaluate these parameters over time. Attachments were mounted in two different configurations of the divergence angle: 10° and 50°. The drop retention force proved to be stable over time. The Locator® R-TX attachment experienced a more rapid decrement of the retention force than the OT Equator® Smart Box. Both tested systems experienced a high drop in retention; this drop tended to stabilize after 1.5 years of use, and it was correlated with the divergence angle. The OT Equator® Smart Box system underwent this loss of retention more gradually than the Locator® R-TX. This study demonstrates preliminary results from a bioengineering and biomechanical point of view, providing useful information for the continuous improvement of these devices and, therefore, for the quality of patients’ oral health. Full article

In recent years the science of dental materials and implantology have taken many steps forward. In particular, it has tended to optimize the implant design, the implant surface, or the connection between implant and abutment. All these features have been improved or modified to obtain a better response from the body, better biomechanics, increased bone implant contact surface, and better immunological response. The purpose of this article, carried out by a multidisciplinary team, is to evaluate and understand, through the use also of bioengineering tests, the biomechanical aspects, and those induced on the patient’s tissues, by dental implants. A comparative analysis on different dental implants of the same manufacturer was carried out to evaluate biomechanical and molecular features. Von Mises analysis has given results regarding the biomechanical behavior of these implants and above all the repercussions on the patient’s tissues. Knowing and understanding the biomechanical characteristics with studies of this type could help improve their characteristics in order to have more predictable oral rehabilitations. Full article

Background: The prosthetic preparation of the teeth for ceramic laminate veneers has to follow the minimally invasive concept brought by the modern Conservative Dentistry and Prosthodontics. However, during the cementation phase under the rubber dam, the loss of the esthetics landmarks could lead to errors in the future positioning of the laminate veneers. Methods: In this article the authors show an accurate operative prosthetic protocol using different fine intraoperative maneuvers and tricks for the realization of ceramic laminates in order to solve the problems of the cementation phase. Results: The treatment of the anterior sector of the upper maxilla with porcelain laminate veneers was realized in a 30 years old woman with aesthetic issues. Conclusion: Different fine intraoperative maneuvers and tricks during teeth preparation, master impression and rubber dam positioning could reduce errors occurring in the cementation phase and increase the predictability of the results. Full article

Vertical loading rate could be associated with residuum and whole body injuries affecting individuals fitted with transtibial prostheses. The objective of this study was to outline one out of five automated methods of extraction of vertical loading rate that stacked up the best against manual detection, which is considered the gold standard during pseudo-prosthetic gait. The load applied on the long axis of the leg of three males was recorded using a transducer fitted between a prosthetic foot and physiotherapy boot while walking on a treadmill for circa 30 min. The automated method of extraction of vertical loading rate, combining the lowest absolute average and range of 95% CI difference compared to the manual method, was deemed the most accurate and precise. The average slope of the loading rate detected manually over 150 strides was 5.56 ± 1.33 kN/s, while the other slopes ranged from 4.43 ± 0.98 kN/s to 6.52 ± 1.64 kN/s depending on the automated detection method. An original method proposed here, relying on progressive loading gradient-based automated extraction, produced the closest results (6%) to manual selection. This work contributes to continuous efforts made by providers of prosthetic and rehabilitation care to generate evidence informing reflective clinical decision-making. Full article

Heterotopic ossification (HO) is a known complication following total hip arthroplasty (THA). The anterior based muscle sparing (ABMS) approach is a variation of a direct anterior approach through the Watson–Jones interval. To date, few studies have evaluated HO formation following this surgery. We examine the incidence of HO in a consecutive series of THAs using this approach by three different surgeons at a single center. Standard preoperative radiographs were examined to determine the type of degenerative arthritis, and follow-up radiographs a minimum of 9 months after surgery were evaluated for the presence and classification of HO. The overall incidence of HO after ABMS THA in this study was 86/233, or 36.9%, which is comparable to recent studies of direct anterior and traditional approaches. Class III and IV HO is uncommon in ABMS surgery (3.9% and 1.3%, respectively) and appears to decrease with increased surgical experience with this technique. Full article

Background: Among tooth anomalies, missing teeth is one of the most frequent, and it can be related to different therapeutical sets of problems. Often, an integrated approach that interests both orthodontists and prosthodontists is necessary, and in some cases also the periodontists. Methods: In this paper the authors report a clinical case of a 14-year-old patient, affected by maxillary bilateral incisors agenesis, molar bilateral II class and deep bite, treated in the Department of Orthodontics and Pedodontics of the University of Messina. The orthodontic treatment target was the distal movement of the maxillary molar, and the recovery of the space necessary for the prosthetic restoration of the missing lateral incisor. Maxillary molars distal movement was performed with a Distal Jet apparatus, skeletally supported by two miniscrews (Distal-Screw, American Orthodontics, Sheboygan, WI, USA). After molar relationship correction, a multi-bracket bimaxillary orthodontic appliance was bonded using Empower Brackets (American Orthodontics, Sheboygan, WI, USA). At the end of orthodontic treatment a Maryland bridge, bonded on the central incisors and cuspids, was used in order to maintain the space necessary for the insertion of dental implants in the region of 1.2 and 2.2. Results: A class II molar relationship was corrected, with an improvement of the deep bite, and the space necessary for implant insertion was recovered Conclusion: A skeletally supported Distal Jet was efficient for molar distalization, with the advantage of not having any loss of anchorage in the anterior part of the dental arch. This apparatus does not need patient compliance, have favorable aesthetics and also give the possibility to perform asymmetric activations. Full article

The objective of this editorial is to present Prosthesis as the main reference point for all researchers involved in biomedical device and prosthesis investigations. Material science and the development of new technologies in the field of regenerative medicine signaled a meeting point between medicine and engineering towards the next generation of prosthetic devices. The aim of the journal is to favor studies and the diffusion of new technologies in the field of rehabilitation medicine. Journal topics will cover everything related to the rehabilitation in humans or animals through the application of new device as well as new advanced surgical techniques and materials. Full article