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1.
Arq. bras. oftalmol ; 88(1): e2023, 2025. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1568847

RESUMEN

ABSTRACT Purpose: To determine the clinical outcomes in patients after type 1 Boston keratoprosthesis surgery and the significance of ultrasound biomicroscopy imaging for postoperative follow-up. Methods: This retrospective analysis included 20 eyes of 19 patients who underwent corneal transplantation with type 1 Boston keratoprosthesis between April 2014 and December 2021. Data on patient demographics, preoperative diagnosis, visual acuity, and postoperative clinical findings were analyzed. Results: Type 1 Boston keratoprosthesis implantation resulted in intermediate- and long-term positive outcomes. However, blindness and other serious complications such as glaucoma, retroprosthetic membrane formation, endophthalmitis, or retinal detachment also occurred. The use of ultrasound biomicroscopy imaging allowed for better evaluation of the back of the titanium plate, anterior segment structures, and the relationship of the prosthesis with surrounding tissues, which provided valuable postoperative information. Conclusion: Regular lifetime monitoring and treatment are necessary in patients who undergo Boston type 1 keratoprosthesis implantation for high-risk corneal transplantation. ultrasound biomicroscopy imaging can be a valuable imaging technique for the evaluation of patients with Boston type 1 keratoprosthesis, providing important information on anterior segment anatomy and potential complications. Further studies and consensus on postoperative follow-up protocols are required to optimize the management of patients with Boston type 1 keratoprosthesis.

2.
Adv Rehabil Sci Pract ; 13: 27536351241272390, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39220728

RESUMEN

Introduction: While each of the 44 National Health Service commissioned artificial limb clinics in the United Kingdom record information about their own prosthetic limb users, these are not collated to give a national picture of amputee epidemiology. The requirement to respond to Freedom of Information (FoI) requests within 20 working days offers another way of extracting data from all centres, and this study describes a first attempt to use this method to update national epidemiological data. Methods: Questions were sent to the FoI email addresses of all 44 centres, requesting numbers of adult unilateral below-knee amputees, adult unilateral above or through-knee amputees and child unilateral above or through-knee amputees (all of K2 level mobility), numbers of people consistently using a prosthesis with a single axis myoelectric hand, and access to an occupational therapist with skills to teach someone to use a myoelectric hand. A FoI request was sent to NHS England seeking release of data that they collect every month from all the prosthetic services which they commission in England. Results: All but one of the UK centres responded, the great majority within 31 days. Incomplete results were generally due to centres finding the questions ambiguous and many did not record mobility levels consistently. While 33 centres had access to skilled occupational therapy, only 4 reported more than 10 patients who constantly used a single axis myoelectric hand. Eighteen centres were unable to provide complete data, and the remainder reported a ranges of 5 to 992 below-knee amputees, 7 to 574 adult above-knee amputees and 0 to 137 child above-knee amputees, suggesting different approaches to managing missing mobility level data. Conclusions: Freedom of Information requests are an inexpensive way of gathering data from NHS prosthetic clinics, which can identify age, sex, level of amputation but not activity levels or use of a prosthesis and hence only gives limited demographic information of the amputee cohort.

3.
Artículo en Inglés | MEDLINE | ID: mdl-39256913

RESUMEN

Bone-anchored limbs (BALs) are socket prosthesis alternatives, directly fixing to residual bone via osseointegrated implant. There is a need to quantify multi-level effects of rehabilitation for transfemoral BAL users (i.e. changes in joint loading and movement patterns). Our primary objective was determining feasibility of using optimal control to predict gait biomechanics compared to ground-truth experimental data from transfemoral BAL users. A secondary objective was examining biomechanical effects from estimated changes in hip abductor muscle strength. We developed and validated a workflow for predicting gait biomechanics in four transfemoral BAL users and investigated the biomechanical effects of altered hip abductor strengths.

4.
Cureus ; 16(8): e66329, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39246918

RESUMEN

When dealing with a partially edentulous patient requiring rehabilitation for a distal extension, the situation becomes challenging if the patient is unwilling to consider placing implants or using a removable prosthesis. A patient with partial tooth loss may find it difficult to receive a satisfactory repair, especially if the missing teeth are at the back. The surrounding gum tissue and the underlying bone ridges provide support for dentures that encase natural teeth. During functional activities, these components are frequently exposed to different stresses, which can substantially affect the remaining natural teeth and bone structure. Precision attachments are complex devices made up of two parts: one incorporated into a detachable dental prosthesis and the other fastened to the natural teeth. Their function is to give the prosthetic stability and retention. A fixed partial denture is impractical when there is no distal abutment. However, by offering a combination prosthesis, this difficulty can be solved. Without requiring surgery, this method provides the benefit of a fixed prosthesis. We are presenting a case of management for a 56-year-old patient with unilateral distal extension with a combined prosthesis of acrylic retained by an extra coronal precision attachment system.

5.
Orthop Traumatol Surg Res ; : 103996, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278401

RESUMEN

INTRODUCTION: The French Society of Orthopedic and Traumatology Surgery (SOFCOT) multicenter register of hip prostheses (HP) has been collecting data from nearly 100 centers in France since 2006. After 18 years of collection, this analysis was carried out to deduce the main conclusions. HYPOTHESIS: Despite its low representativeness (3%), this register provides instructive information on the evolution of hip arthroplasty techniques and implants in France. MATERIAL AND METHODS: As of the 31st of December 2023, 58,314 primary HP were recorded, mainly for primary osteoarthritis (44,535 hips, 76.4%), followed by femoral neck fractures (4,880, 8.4%). The mean age was 71 years (SD, 11.6) with 57% (33,305) women. In total, 73% of the implants were uncemented and 170 brand names were listed. Over the same period, 5,853 first reoperations were recorded. Social security number matching identified 777 revisions of an already registered primary HP. The revision index for 100 components observed per year (RCOY) allows the performance of implants to be compared (alert threshold if >1.3). RESULTS: The causes of these 777 early first revisions at a short mean follow-up (MF) of 1.4 years were: dislocation (191/777, 24.6%), peri-prosthetic fracture (175, 22.5%), aseptic loosening (103, 13.3%) and acute infection (101, 13%). The RCOY for all primary HP was 0.25 at 5.4 years of MF. This index: (i) Depended on the type of implant: 0.23 for HP with dual-mobility cups (DMC) at 4.7 years of MF; 0.25 for HP with short femoral stems at 4.4 years; and 0 for resurfacing after only 2.5 years (due to the creation of a specific mandatory register, since 2015, which put an end to the voluntary inclusion of resurfacing in this general register). (ii) Depended on the method of fixation: 0.21 for completely cemented HP at 7.8 years of MF and 0.29 at 4.9 years for completely uncemented HP. (iii) Based on the friction torque: 0.12 for conventional metal-metal HP at 9.7 years of MF and 0.29 at 5.1 years for alumina-alumina HP. (iv) Finally, 3 arthroplasties with 3 uncemented stems had an RCOY > 1.3. DISCUSSION: Although the RCOY of HP with conventional cemented femoral stems is only 0.16 at 6.6 years of MF, while that of HP with conventional uncemented stems is 0.29 at 4.9 years, the trend towards uncemented femoral fixation has continued to intensify. Resurfacing gives good results following careful selection of implants but with a short MF of 2.5 years. Conventional metal-metal bearings continue to give excellent results at almost 10 years of MF. The 10-year survival of HP with short femoral stems is favorable compared to that of HP with conventional stems. There is no significant difference between the survival of HP with conventional versus highly cross-linked polyethylene liner. CONCLUSION: Despite its low representativeness, this register provides information on the techniques and implants used in France. The addition of clinical monitoring and PROM within the new SOFCOT-RENACOT registry as well as re-certification obligations should help promote its development. LEVEL OF EVIDENCE: III; prospective comparative study.

6.
Proc Inst Mech Eng H ; : 9544119241279630, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39275850

RESUMEN

The rapid advancement of artificial intelligence (AI) in healthcare has the potential to revolutionize the global healthcare sector and medicine in general. However, integrating AI technologies in healthcare requires access to large amounts of personal health-related data (HRD), which raises concerns regarding confidential personal information considering unregulated and not transparent data ownership. Setting up the patient's welfare as an unquestionable principle, this commentary explores the various ethical aspects of using HRD in AI applications, focusing on informed consent, data ownership, data sharing, financial considerations, accountability, and ethical standards. Three models of potential collaboration between AI-specializing firms and healthcare providers are evaluated: the commercial model, the equitable profit-sharing model, and the public-funded non-profit model. Each model has its advantages and challenges, necessitating a careful balance between ethical considerations, financial implications, and technological advancements. Policymakers and healthcare regulators are urged to establish transparent legislation to safeguard patient privacy, ensure informed consent, and promote the responsible use of HRD in AI applications. This commentary emphasizes the importance of addressing ethical issues to protect basic patient rights, foster responsible collaborations, and ensure the ethical use of health-related data in AI-based healthcare applications. While the coexistence of regulated AI and healthcare professionals is inevitable for validating the cost-effectiveness of AI use in healthcare economics, the transparency of HRD sources is deemed of utmost importance in the best interest of the patient.

7.
Front Cell Dev Biol ; 12: 1438716, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39263323

RESUMEN

Background: Neural cell-electrode coupling is crucial for effective neural and retinal prostheses. Enhancing this coupling can be achieved through surface modification and geometrical design to increase neuron-electrode proximity. In the current research, we focused on designing and studying various biomolecules as a method to elicit neural cell-electrode adhesion via cell-specific integrin mechanisms. Methods: We designed extracellular matrix biomimetic molecules with different head sequences (RGD or YIGSR), structures (linear or cyclic), and spacer lengths (short or long). These molecules, anchored by a thiol (SH) group, were deposited onto gold surfaces at various concentrations. We assessed the modifications using contact angle measurements, fluorescence imaging, and X-ray Photoelectron Spectroscopy (XPS). We then analyzed the adhesion of retinal cells and HEK293 cells to the modified surfaces by measuring cell density, surface area, and focal adhesion spots, and examined changes in adhesion-related gene and integrin expression. Results: Results showed that YIGSR biomolecules significantly enhanced retinal cell adhesion, regardless of spacer length. For HEK293 cells, RGD biomolecules were more effective, especially with cyclic RGD and long spacers. Both cell types showed increased expression of specific adhesion integrins and proteins like vinculin and PTK2; these results were in agreement with the adhesion studies, confirming the cell-specific interactions with modified surfaces. Conclusion: This study highlights the importance of tailored biomolecules for improving neural cell adhesion to electrodes. By customizing biomolecules to foster specific and effective interactions with adhesion integrins, our study provides valuable insights for enhancing the integration and functionality of retinal prostheses and other neural implants.

8.
Ann Pharm Fr ; 2024 Sep 11.
Artículo en Francés | MEDLINE | ID: mdl-39270835

RESUMEN

OBJECTIVES: The objective of our study is to take stock of the cranioplasty implants used within our establishment. MATERIALS AND METHOD: We analyzed the patients files who underwent craniectomy followed by cranioplasty between 2017 and 2023, with at least 1 year of follow-up after cranioplasty (n=75). The data were extracted from the computerized patient file (DxCare®, Dédalus) and the pharmaceutical management tool for drugs and sterile medical devices (Pharma®, Computer Engineering). The sex ratio, indication for craniectomy, operating time, time between craniectomy and cranioplasty, complications and aesthetic result were statistically analyzed. RESULTS: The main indications are stroke (n=59; 78.5%) and aneurysms (n=7; 9.5%). Among the 75 patients, 52 benefited from the placement of a custom implant (PolyEtherEtherCetone/PEEK or Hydroxyapatite) and 23 from cementoplasty. The operating time was significantly shorter (p < 0.05) for custom cranioplasty (1.93 ± 0.61 h vs 1.62 ± 0.53). Only 4 patients (5.3%) were not satisfied with the aesthetic result following the placement of a custom implant. A greater risk of infection was found in the context of cementoplasty (43% for cementoplasties vs 25% for the custom implant, so χ2(p = 0.1095), this difference not being statistically significant. CONCLUSION: This collaborative work between the pharmacy and the adult neurosurgery department served to establish an initial register for monitoring patients who have undergone cranioplasty for whom the ideal implant remains to be determined.

9.
Artículo en Inglés | MEDLINE | ID: mdl-39232864

RESUMEN

The management of infected temporomandibular joint prostheses presents a surgical challenge. In certain instances, an intermediate approach involving biofilm debridement and local antibiotic instillation may obviate the need for prosthesis removal. This technical note describes an update of the technique outlined by Wolford for managing infections, in which improved materials are used to implement the technique.

10.
J Biomed Mater Res B Appl Biomater ; 112(9): e35483, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39229802

RESUMEN

Although deterioration of silicone maxillofacial prostheses is severely accentuated in smoking patients, the phenomenon has not been systematically studied. To address a gap in the literature concerning the stability of maxillofacial prostheses during service, in this contribution, the effect of cigarette smoke on the aspect and physical properties of M511 silicone elastomer was evaluated. The aspect, surface, and overall properties of the silicone material, pigmented or not, were followed by AFM, color measurements, FTIR, water contact angle measurements, TGA-DTG and DSC, hardness and compression stress-strain measurements. The types of the contaminants adsorbed were assessed by XRF, ESI-MS, MALDI-MS, and NMR spectral analyses. Important modifications in color, contact angle, surface roughness, local mechanical properties, and thermal properties were found in the silicone material for maxillofacial prostheses after exposure to cigarettes smoke. The presence of lead, nicotine, and several other organic compounds adsorbed into the silicone material was emphasized. Slight decrease in hardness and increase in Young's modulus was found. The combined data show important impact of cigarette smoke on the silicone physical properties and could indicate chemical transformations by secondary cross-linking. To our knowledge, this is the first study making use of complementary physical methods to assess the effect of cigarette smoke on the aspect and integrity of silicone materials for maxillofacial prostheses.


Asunto(s)
Ensayo de Materiales , Prótesis Maxilofacial , Humo , Humanos , Elastómeros de Silicona/química , Nicotiana/química , Color
11.
Stomatologiia (Mosk) ; 103(4): 10-19, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-39171338

RESUMEN

THE AIM OF THE STUDY: To develop and implement a comprehensive algorithm for the rehabilitation of patients after partial resection of the mandible using a titanium «growing¼ endoprosthesis. MATERIAL AND METHODS: The study included 16 patients aged 2 to 7 years, with benign (6 cases) and malignant (10 cases) tumors of the mandible. The patients were divided into 2 groups depending on the time of fixation of the endoprosthesis. Group 1 included patients with simultaneous installation of a prosthesis (7 people). Group 2 included patients with delayed installation of an endoprosthesis (9 people). For the reconstruction of the mandible, «growing¼ titanium endoprostheses made of Ti6Al4V alloy of various designs were used. Removable orthodontic devices of mechanical and functional type of action, standard elastic mouthguards were used in the process of dental treatment. RESULTS: A comprehensive algorithm has been developed for the rehabilitation of children after partial resection of the mandible, depending on the time of fixation of the prosthesis and the volume of surgical intervention. CONCLUSION: The developed algorithm of complex rehabilitation using a «growing¼ endoprosthesis and dental support at the pre and postoperative stages allows to reduce the volume of secondary deformation of facial structures and dentition.


Asunto(s)
Mandíbula , Neoplasias Mandibulares , Titanio , Humanos , Niño , Preescolar , Neoplasias Mandibulares/cirugía , Masculino , Femenino , Mandíbula/cirugía , Aleaciones , Algoritmos , Reconstrucción Mandibular/métodos , Reconstrucción Mandibular/instrumentación
12.
Int J Oral Maxillofac Implants ; : 1-20, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39172437

RESUMEN

Purpose: Immediate implant placement is a reliable solution to replace hopeless teeth, but this procedure may be associated to an increased risk of soft tissue complications in case of thin biotype. The use of tissue-level implants with a convergent transmucosal profile has been advocated to increase space for soft tissue, contributing to improve their stability and esthetics. The aim of this retrospective study was to evaluate the esthetic outcomes and the Patient-Reported Outcome Measures (PROMs) of immediately placed implants with a convergent transmucosal profile. Materials and methods: This single-cohort, monocentric, retrospective clinical study was conducted on patients treated with an immediately placed implant in the esthetic zone (from premolar to premolar). All the eligible patients were recalled for a clinical and radiographic follow-up visit. Results: This study included 20 patients (8 males, 12 females) with an average age of 55.5± 6.8 years, who received 20 implants, with a mean follow-up of 46.5± 15.3 months. At the time of follow-up, immediately placed implants showed a mean Marginal Bone Loss of 0.42± 0.49 mm, and a statistically significant improvement of the esthetic parameters from baseline to the last available follow-up; in particular, Pink and White esthetic scores (p=.001) and Papilla Index at mesial and distal sites (p<.001). All the patients reported a high satisfaction (VAS>9) both from esthetic and functional point of view. Conclusion: Immediately placed implants with convergent transmucosal profile in the esthetic zone showed good clinical and esthetic outcomes, with stable results over time.

13.
J Vet Dent ; : 8987564241268748, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39196358

RESUMEN

Captive felids are prone to dental fractures, and the recommended treatment involves endodontics (root canal treatment), prosthodontics (coronal restoration), or tooth extraction. A single-unit dental prosthesis can restore the crown of a tooth whose structure has been partially or completely lost. Nine animals out of 35 captive wild felids kept under human care in 7 different Brazilian institutions were selected for the study. The animals selected included the little spotted cat (Leopardus tigrinus), ocelot (L. pardalis), margay cat (L. wiedii), pampas cat (L. colocolo), jaguarundi cat (Puma yagouaroundi), puma (P. concolor), jaguar (Panthera onca), lion (P. leo), and tiger (P. tigris). Nineteen canine prosthodontic crowns (18 full and one 3/4) were cemented using dual-cure resin cement and their feasibility was evaluated for 30 months. Fourteen (73%) remained fixed to the tooth and 5 (27%) were lost after the evaluation period. This study aimed to assess the longevity of prosthodontic crowns in the canine teeth of wild felids. Furthermore, it aimed to determine the functionality and longevity of teeth which had received prosthodontic crowns.

14.
SAGE Open Med Case Rep ; 12: 2050313X241269572, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39157031

RESUMEN

Implant-supported complete dentures are a common procedure for patients with mandibular edentulism problems. This article documents the protocol for immediate functional loading of fixed transient mandibular prostheses with fully moldable attachments and distal extensions to prevent fractures. A 56-year-old female patient was referred to the Oral Rehabilitation and Implantology Service due to periodontal problems, difficulty in chewing capacity and aesthetic compromise. The patient was treated in a single surgical procedure with dental extractions, guided regularization of the alveolar process and guided placement of five interforaminal implants and placement of functional fixed mandibular prostheses with immediate loading with personalized UCLA'S, distal extensions and short arc occlusal scheme. At 3 months postoperatively, the definitive placement of fixed mandibular metal acrylic prostheses and conventional upper prostheses was performed. The functional and aesthetic integrity of the fixed mandibular prosthesis implant preserved with UCLA'S documents that implant placement in the interforaminal zone with an immediate loading protocol is a viable treatment option for prosthetic rehabilitation of the fully edentulous mandibular arch and that design with distal extensions in the posterior sector of the mandibular arch is an effective option to avoid fracture of the prostheses, presenting a survival of the five mandibular implants of 100% at 1 year postoperatively.

15.
Front Neurosci ; 18: 1425226, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39114486

RESUMEN

Cochlear implants (CI) represent incredible devices that restore hearing perception for those with moderate to profound sensorineural hearing loss. However, the ability of a CI to restore complex auditory function is limited by the number of perceptually independent spectral channels provided. A major contributor to this limitation is the physical gap between the CI electrodes and the target spiral ganglion neurons (SGNs). In order for CI electrodes to stimulate SGNs more precisely, and thus better approximate natural hearing, new methodologies need to be developed to decrease this gap, (i.e., transitioning CIs from a far-field to near-field device). In this review, strategies aimed at improving the neural-electrode interface are discussed in terms of the magnitude of impact they could have and the work needed to implement them. Ongoing research suggests current clinical efforts to limit the CI-related immune response holds great potential for improving device performance. This could eradicate the dense, fibrous capsule surrounding the electrode and enhance preservation of natural cochlear architecture, including SGNs. In the long term, however, optimized future devices will likely need to induce and guide the outgrowth of the peripheral process of SGNs to be in closer proximity to the CI electrode in order to better approximate natural hearing. This research is in its infancy; it remains to be seen which strategies (surface patterning, small molecule release, hydrogel coating, etc.) will be enable this approach. Additionally, these efforts aimed at optimizing CI function will likely translate to other neural prostheses, which face similar issues.

16.
Artículo en Inglés | MEDLINE | ID: mdl-39177417

RESUMEN

BACKGROUND: Tooth- and implant-supported fixed dental prostheses are well-documented and aesthetic treatment alternatives, and after a comprehensive periodontal treatment, a protocol with a good long-term prognosis if the maintenance program is strictly followed. AIM: To reexamine a pre-existing patient cohort in order to obtain estimated long-term survival and complication outcomes of fixed dental prostheses. MATERIALS AND METHODS: For this study, patients treated with fixed dental prostheses between 1978 and 2002 were reexamined between 2019 and 2020. The restorations were divided in single crowns and fixed dental prostheses supported by teeth (TSC, FPTDP) and implants (ISC, FPIDP). Survival and complication rates were obtained. Kaplan-Meier functions were used to model complication probabilities, and average hazard ratios of different strata were compared using weighted Cox regression. RESULTS: The mean observation time of 40 patients and 223 reconstructions was 20.3 (±9.7, 1.2-36.2) years. The estimated survival rates were 84% (CI: 77%-92%) for TSC, 63% (CI: 51%-79%) for FPTDP, 87% (CI: 71%-100%) for ISC, and 64% (CI: 34%-100%) for FPIDP after 25 years. Biological complications included carious lesions (10.6%), periodontitis (7.9%), and peri-implantitis (6.8%). Technical complications included chipping (20.2%) and loss of retention (10.8%). CONCLUSION: Biological complications lead to abutment loss in more than two-thirds of cases, regardless of the type of abutment (tooth or implant). Technical complications are less associated with abutment loss than biological complications.

17.
Sci Rep ; 14(1): 18493, 2024 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-39122740

RESUMEN

This study investigated how muscle synergies adapt in response to unexpected changes in object weight during lifting tasks. The aim was to discover which motor control strategies individuals use to maintain their grasping performance. Muscle synergies were extracted from the muscle activity of fifteen healthy participants who lifted objects of identical appearance but varying weights in a randomized order, which introduced artificial perturbations. Reaching and manipulation phases of object lifting were analyzed using constrained non-negative matrix factorization and k-means clustering. Participants exhibited a perturbation-independent and thus consistent recruitment of spatial synergy components, while significant adaptations in muscle synergy activation occurred in response to unexpected perturbations. Perturbations caused by unexpectedly heavy objects led to delayed and gradual increases in muscle synergy activation until the force required to lift the object was reached. In contrast, perturbations caused by lighter objects led to reductions in excess muscle synergy activation occurring later. Sensorimotor control maintains the modularity of muscle synergies. Even when external mechanical perturbations occur, the grasping performance is preserved, and control is adapted solely through muscle synergy activation. These results suggest that using pure spatial synergy components as control signals for myoelectric arm prostheses may prevent them from malfunctioning due to external perturbations.


Asunto(s)
Fuerza de la Mano , Músculo Esquelético , Humanos , Masculino , Fuerza de la Mano/fisiología , Músculo Esquelético/fisiología , Adulto , Femenino , Adulto Joven , Electromiografía , Adaptación Fisiológica , Fenómenos Biomecánicos , Desempeño Psicomotor/fisiología
18.
Methods Mol Biol ; 2835: 317-323, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39105927

RESUMEN

Prostheses play a vital role in restoring function and mobility to individuals with physical disabilities. This study focuses on the procedure to create customized prostheses using semirigid molds obtained from additive technologies. This innovative methodology aims to improve the fit and comfort of prostheses.The manufacturing process of prostheses using semirigid molds combined with additive technologies involves several key phases. These include the use of computed tomography (CT) of the affected area, computer-aided design, and the production of custom mold models.This study introduces the main production phases of customized prostheses, based on the strategy that involves the manufacturing of semirigid molds, by additive manufacturing (AM). This approach improves fit, comfort, and integration of prostheses into patients' daily lives. In particular, prostheses for cranioplasty are described in this study.


Asunto(s)
Diseño Asistido por Computadora , Prótesis e Implantes , Diseño de Prótesis , Humanos , Tomografía Computarizada por Rayos X/métodos , Impresión Tridimensional
19.
J Orthop Surg Res ; 19(1): 520, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39210457

RESUMEN

BACKGROUND: Commercially available osseointegrated devices for transfemoral amputees are limited in size and thus fail to meet the significant anatomical variability in the femoral medullary canal. This study aimed to develop a customized osseointegrated stem to better accommodate a variety of femoral anatomies in transfemoral amputees than off-the-shelf stems. Customization is expected to enhance cortical bone preservation and increase the stem-bone contact area, which are critical for the long-term stability and success of implants. METHODS: A customized stem (OsteoCustom) was designed based on the statistical shape variability of the medullary canal. The implantability of the OsteoCustom stem was tested via 70 computed tomography (CT) images of human femurs and compared to that of a commercial device (OFI-C) for two different resection levels. The evaluations included the volume of cortical bone removed and the percentage of stem-bone contact area for both resection levels. Statistical significance was analyzed using paired and unpaired t tests. RESULTS: The OsteoCustom stem could be virtually implanted in all 70 femurs, while the OFI-C was unsuitable in 19 cases due to insufficient cortical thickness after implantation, further emphasizing its adaptability to varying anatomical conditions. The OsteoCustom stem preserved a greater volume of cortical bone than did the OFI-C. In fact, 42% less bone was removed at the proximal resection level (3.15 cm³ vs. 5.42 cm³, p ≤ 0.0001), and 33% less at the distal resection level (2.25 cm³ vs. 3.39 cm³, p = 0.003). The stem-bone contact area was also greater for the OsteoCustom stem, particularly at the distal resection level, showing a 20% increase in contact area (52.3% vs. 32.2%, p = 0.002) compared to that of the OFI-C. CONCLUSIONS: The OsteoCustom stem performed better than the commercial stem by preserving more cortical bone and achieving a greater stem-bone contact area, especially at distal resection levels where the shape of the medullary canal exhibits more inter-subject variability. Optimal fit in the distal region is of paramount importance for ensuring the stability of osseointegrated implants. This study highlights the potential benefits of customized osseointegrated stems in accommodating a broader range of femoral anatomies, with enhanced fit in the medullary canal.


Asunto(s)
Amputados , Prótesis Anclada al Hueso , Fémur , Oseointegración , Diseño de Prótesis , Humanos , Fémur/cirugía , Fémur/diagnóstico por imagen , Masculino , Oseointegración/fisiología , Femenino , Persona de Mediana Edad , Adulto , Anciano , Miembros Artificiales , Tomografía Computarizada por Rayos X , Implantación de Prótesis/métodos , Adulto Joven
20.
Dent Mater ; 40(10): 1524-1533, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39107223

RESUMEN

OBJECTIVES: To compare the interfacial fracture toughness (IFT) with or without aging, of four different classes of CAD-CAM ceramic and composite materials bonded with self-adhesive resin cement to titanium alloy characteristic of implant abutments. METHODS: High translucent zirconia (Katana; KAT), lithium disilicate-based glass-ceramic (IPS. emax.CAD; EMX), polymer-infiltrated ceramic network material (PICN) (Vita Enamic; ENA), and dispersed filler composite (Cerasmart 270; CER) were cut into equilateral triangular prisms and bonded to titanium prisms with identical dimensions using Panavia SA Cement Universal. The surfaces were pretreated following the manufacturers' recommendations and developed interfacial area ratio (Sdr) of the pretreated surfaces was measured. IFT was determined using the Notchless Triangular Prism test in a water bath at 36 °C before and after thermocycling (10,000 cycles) (n = 40 samples/material). RESULTS: IFT of the materials ranged from 0.80 ± 0.25 to 1.10 ± 0.21 MPa.m1/2 before thermocycling and from 0.71 ± 0.24 to 1.02 ± 0.25 MPa.m1/2 after thermocycling. There was a statistical difference between IFT of CER and the two top performers in each scenario: KAT and EMX before aging, and KAT and ENA after aging. Thermocycling significantly decreased IFT of EMX. The Weibull modulus of IFT was similar for all materials and remained so after thermocycling. Sdr measurements revealed that ENA (7.60)>Ti (4.97)>CER (2.85)>KAT (1.09)=EMX (0.96). SIGNIFICANCE: Dispersed filler CAD-CAM composite showed lower performance than the other materials. Aging only affected IFT of Li-Si glass-ceramic, whereas zirconia and PICN performed equally well, probably due to their chemical bonding potential and surface roughness respectively.


Asunto(s)
Cerámica , Diseño Asistido por Computadora , Análisis del Estrés Dental , Ensayo de Materiales , Propiedades de Superficie , Titanio , Cerámica/química , Titanio/química , Circonio/química , Porcelana Dental/química , Recubrimiento Dental Adhesivo , Cementos de Resina/química , Materiales Dentales/química , Resinas Compuestas/química , Aleaciones Dentales/química , Implantes Dentales
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