Bone fractures pose a serious challenge for the healthcare system worldwide. A total of 17.5% of these fractures occur in the distal radius. Traditional cast materials commonly used for treatment have certain disadvantages, including a lack of mechanical and water resistance, poor hygiene, and odors. Three-dimensional printing is a dynamically developing technology which can potentially replace the traditional casts. The aim of the study was to examine and compare the traditional materials (plaster cast and fiberglass cast) with Polylactic Acid (PLA) and PLA–CaCO3 composite materials printed using Fused Filament Fabrication (FFF) technology and to produce a usable cast of each material. The materials were characterized by tensile, flexural, Charpy impact, Shore D hardness, flexural fatigue, and variable load cyclic tests, as well as an absorbed water test. In addition, cost-effectiveness was evaluated and compared. The measured values for tensile strength and flexural strength decreased with the increase in CaCO3 concentration. In the fatigue tests, the plaster cast and the fiberglass cast did not show normal fatigue curves; only the 3D-printed materials did so. Variable load cyclic tests showed that traditional casts cannot hold the same load at the same deflection after a higher load has been used. During these tests, the plaster cast had the biggest relative change (−79.7%), compared with −4.8 % for the 3D-printed materials. The results clearly showed that 3D-printed materials perform better in both static and dynamic mechanical tests; therefore, 3D printing could be a good alternative to customized splints and casts in the near future.
Recently, additive manufacturing has become increasingly available for personalized biomedical applications; still, the material science is one of the primary contentions. Polyamide (PA) has several beneficial characteristics, including mechanical strength, biocompatibility, and flexibility, making it an excellent candidate for biomedical applications. Based on that, this systematic review aims to summarize and critically evaluate the state‐of‐the‐art knowledge of 3D printed polyamide and its composites with respect to material sciences and biomedical applications. Medline, Embase, Scopus, Cochrane, and Web of Science databases were searched for biomedical applications of additively manufactured polyamide. Overall, 1889 papers were screened, and 114 articles were finally selected to be included in this review. This work consists of three sections aiming at a comprehensive biomedical evaluation of the material, starting with mechanical characteristics of polyamide and its composites, considering distinct 3D printing technologies, followed by tissue engineering, drug delivery, and personalized biomedical solutions. Finally, biomedical educational and patient information applications are discussed with insights into future medical applications. Based on the results, polyamide and its composites are suggested to be excellent candidates for biomedical applications. However, this systematic approach highlighted the distinct need for thorough mechanical analysis and clinical trials based on universal standards for future biomedical applications.
The aim of this retrospective study was to analyze the occurrence and characteristics of pre-eruptive intracoronal resorptions in a clinical orthodontic patient population. Patients treated in an orthodontic department (University of Pécs, Pécs, Hungary) were included. Unerupted teeth on panoramic radiographs were analyzed for intracoronal radiolucent lesions. For each patient, the demographic data, jaw localization, number of unerupted teeth with pre-eruptive intracoronal resorption lesions, number of lesions per tooth, size and localization of pre-eruptive intracoronal resorption defects, affected tooth's surface, pulp involvement and ectopic position of the tooth with defects were recorded. In the 3,143 patients investigated, 55 teeth in 49 patients showed pre-eruptive intracoronal resorption lesions (subject incidence: 1.56%). The incidence on unerupted teeth was 0.25%. Pre-eruptive intracoronal resorption was significantly more common in mandibles (43 mandibular vs. 12 maxillary lesions) with an odds ratio of 12.84 (95% Confidence Interval: 5.19–31.74) and no gender differences were found (p = 0.746). The occurrence of pre-eruptive intracoronal resorption was highest in the youngest (7–10 years) mixed dentition status group (p < 0.001). Most of the lesions (44 of 55, or 80.0%) were localized in the dentin, occupying two-third or less of the dentin thickness. Only 12.73% (7/55) of the lesions were not localized on the occlusal surface. Of the lesions, 89.1% (49/55) showed no obvious size increase over an average follow-up of 36.4 ± 8.1 months. Pre-eruptive intracoronal resorption may occur mainly in the mixed dentition stage in orthodontic patients. Careful and attentive radiographic evaluations may facilitate early detection and follow-up of the lesions’ possible dimensional changes, especially when resorption influences orthodontic extraction therapy.
Conductive polymer composites are commonly present in flexible electrodes for neural interfaces, implantable sensors, and aerospace applications. Fused filament fabrication (FFF) is a widely used additive manufacturing technology, where conductive filaments frequently contain carbon-based fillers. In this study, the static and dynamic mechanical properties and the electrical properties (resistance, signal transmission, resistance measurements during cyclic tensile, bending and temperature tests) were investigated for polylactic acid (PLA)-based, acrylonitrile butadiene styrene (ABS)-based, thermoplastic polyurethane (TPU)-based, and polyamide (PA)-based conductive filaments with carbon-based additives. Scanning electron microscopy (SEM) was implemented to evaluate the results. Cytotoxicity measurements were performed. The conductive ABS specimens have a high gauge factor between 0.2% and 1.0% strain. All tested materials, except the PA-based conductive composite, are suitable for low-voltage applications such as 3D-printed EEG and EMG sensors. ABS-based and TPU-based conductive composites are promising raw materials suitable for temperature measuring and medical applications.
Maxillofacial bone defects can have a profound impact on both facial function and aesthetics. While various biomaterial scaffolds have shown promise in addressing these challenges, regenerating bone in this region remains complex due to its irregular shape, intricate structure, and differing cellular origins compared to other bones in the human body. Moreover, the significant and variable mechanical loads placed on the maxillofacial bones add further complexity, especially in cases of difficult-to-treat medical conditions. This review provides a brief overview of medication-related osteonecrosis of the jaw (MRONJ), highlighting the medication-induced adverse reactions and the associated clinical challenges in treating this condition. The purpose of this manuscript is to emphasize the role of biotechnology and tissue engineering technologies in therapy. By using scaffold materials and biofactors in combination with autologous cells, innovative solutions are explored for the repair of damaged facial bones. The ongoing search for effective scaffolds that can address these challenges and improve in vitro bone preparation for subsequent regeneration in the maxillofacial region remains critical. The primary purpose of this review is to spotlight current research trends and novel approaches in this area.