Prosthesis, Volume 3, Issue 2 (June 2021) – 7 articles

The outcomes of prosthetic rehabilitation after lower limb loss are, in large part, affected by the effectiveness of the provided gait retraining. The noted prevalence of adverse long-term effects, such as further joint and muscle degeneration, suggests that traditional rehabilitation programs have limitations. Recent advances in technology and in the understanding of motor learning promise the potential for better gait retraining interventions. This article reviews current literature on systems and methodologies of improving gait parameters in those with lower limb prostheses via exercise programs and various biofeedback systems. A total of 13 articles were included in the qualitative analysis. Findings indicate that many of the investigated systems are able to effectively analyze and change gait in the target population, but there remain considerable gaps in the knowledge. It has been noted that feedback modalities and dosage must be customized based on patient characteristics and rehabilitation goals, yet there is currently not enough published evidence to inform such customization. Full article

Different all-ceramic crown designs are available to perform indirect restoration; however, the mechanical response of each model should still be elucidated. The study aims to evaluate the stress distribution in three different zirconia crown designs using finite element analysis. Different three-dimensional molar crowns were simulated: conventional bilayer zirconia covered with porcelain, a monolithic full-contour zirconia crown, and the cutback modified zirconia crown with porcelain veneered buccal face. The models were imported to the computer-aided engineering (CAE) software. Tetrahedral elements were used to form the mesh and the mechanical properties were assumed as isotropic, linear and homogeneous materials. The contacts were considered ideal. For the static structural mechanical analysis, 100 N occlusal load was applied and the bone tissue was fixed. Maximum principal stress showed that the stress pattern was different for the three crown designs, and the traditional bilayer model showed higher stress magnitude comparing to the other models. However, grayscale stress maps showed homogeneous stress distribution for all models. The all-ceramic crown designs affect the stress distribution, and the cutback porcelain-veneered zirconia crown can be a viable alternative to adequate function and esthetic when the monolithic zirconia crown cannot be indicated. Full article

To ensure the long-term success of a dental implant, it is imperative to understand how chewing loads are transferred through the implant prosthetic components to the surrounding bone tissue. The stress distribution depends on several factors, such as load type, bone–implant interface, shape and materials of the fixture and quality and quantity of the bone. These aspects are of fundamental importance to ensure implant stability and to evaluate the remodelling capacity of the bone tissue to adapt to its biomechanical environment. A bone remodelling algorithm was formulated by the authors and implemented by means of finite element simulations on four different implants with several design characteristics. Internal bone microstructure and density, apposition/resorption of tissue and implant stability were evaluated over a period of 12 months, showing the influence of the geometry on bone tissue evolution over time. Bone remodelling algorithms may be a useful aid for clinicians to prevent possible implant failures and define an adequate implant prosthetic rehabilitation for each patient. In this work, for the first time, external bone remodelling was numerically predicted over time. Full article

Prosthesis treatment requires the close interaction of different actors. In fitting prostheses to patients, special attention is given to the manufacturing of the socket. The continuous development of the technologies involved in the fitting and optimization of prostheses is shown in the literature. The assessment of orthopedic technicians and their influence in the process is thus far largely unexplored. Ten orthopedic technicians were interviewed about the socket fitting process after transfemoral amputation. The research goal was to clarify the socket treatment process with regards to the German context. The results showed that the orthopedic technicians focussing on the patient during the fitting process. This study underlines the importance of interaction and empathy. Volume fluctuations are decisive within the treatment process and are interactively influenced by various factors. Furthermore, the research emphasizes the need for appropriate assistive technologies and the potential for the further development of existing systems. Full article

The nature of immediate implant placement followed by an immediate restoration protocol makes it particularly suited to the anterior maxilla. In addition to saving treatment time and avoiding additional surgical procedures, this protocol has been reported to improve aesthetic outcomes by supporting the peri-implant tissues during the implant healing phase through the use of a provisional restoration. This case report documents the use of this protocol in a patient with a failing maxillary anterior tooth and reports on the soft and hard tissue changes over an observation period of 10 years. An implant was immediately placed after removal of a failing maxillary central incisor followed by the provision of a screw retained provisional crown on the same day. A definitive restoration was placed after a 3-month healing period. Not only did this protocol manage to maintain peri-implant bone levels over the 10-year follow-up period, excellent aesthetic outcomes and very limited soft tissue recession were observed with the use of this technique. Full article

The purpose of this survey was to determine removable partial denture (RPD) framework design concepts, new materials, and digital technology that are currently being taught in the predoctoral RPD curriculums in the U.S. dental schools. A questionnaire including RPD framework design concepts, materials, and digital technology was created on Qualtrics. The link to the questionnaire was distributed by email in May 2018 to U.S. dental schools. Thirty-nine of the sixty-six schools responded, yielding a response rate of 59%. Most schools are utilizing textbooks by McCracken and/or Stewart as their primary reference (90%). Only a few schools teach incisal rest (24%) and intra-coronal retainers (8%) in the clinic. The majority of schools teach three or less clasp assembly variations for distal extension RPD scenarios and utilize altered cast impression techniques only for selective patient scenarios. Half of schools currently utilize digital technology in their RPD curriculum. Although twenty-five schools (69%) indicated that implant-assisted RPD (IARPD) is being taught in the curriculum, only nineteen of them teach IARPDs in the clinic. Half of schools are utilizing non-metal clasp denture (NMCD) in their curriculum; most of these school provide this treatment as immediate/interim partials or long-term interim partials. Many U.S. dental schools are simplifying RPD design concepts and principles that are being taught. More schools are introducing new concepts and materials such as IARPD and NMCDs while incorporating digital technology in their predoctoral RPD curriculum. Full article

People who either use an upper limb prosthesis and/or have used services provided by a prosthetic rehabilitation centre, hereafter called users, are yet to benefit from the fast-paced growth in academic knowledge within the field of upper limb prosthetics. Crucially over the past decade, research has acknowledged the limitations of conducting laboratory-based studies for clinical translation. This has led to an increase, albeit rather small, in trials that gather real-world user data. Multi-stakeholder collaboration is critical within such trials, especially between researchers, users, and clinicians, as well as policy makers, charity representatives, and industry specialists. This paper presents a co-creation model that enables researchers to collaborate with multiple stakeholders, including users, throughout the duration of a study. This approach can lead to a transition in defining the roles of stakeholders, such as users, from participants to co-researchers. This presents a scenario whereby the boundaries between research and participation become blurred and ethical considerations may become complex. However, the time and resources that are required to conduct co-creation within academia can lead to greater impact and benefit the people that the research aims to serve. Full article