Search Results (335)

Objectives: This study compared the cyclic fatigue resistance and the mechanical, thermal, and metallurgical characteristics of SlimShaper^® and SlimShaper PRO^® instruments. Both sequences include three instruments (ZS1–ZS3) with identical geometries, although SlimShaper PRO features an apically modified thermal treatment. Methods: Cyclic fatigue tests were performed using a standardized metallic guide with a 45° curvature, on six instruments of each sequence type. Fractured segments were measured, and fracture surfaces were analyzed using optical microscopy and Scanning Electron Microscopy (SEM). Elemental composition was assessed by Energy-dispersive Spectroscopy (EDS), while Differential Scanning Calorimetry (DSC) was used to determine transformation temperatures and enthalpy. Results: ZS1 and ZS1 PRO exhibited comparable cyclic fatigue resistance, whereas ZS2 and ZS3 showed significantly higher resistance than their PRO counterparts. SlimShaper PRO^® instruments fractured with segments approximately 0.5–1 mm longer. EDS confirmed that both instruments were made of NiTi, with minor differences in surface composition, while DSC demonstrated similar enthalpy values but distinct transformation ranges. At room temperature (27 °C), SlimShaper^® ZS2 remained predominantly martensitic, whereas ZS2 PRO could be partially austenitic, explaining its observed reduced fatigue resistance. The results of the DSC allowed to deduce the microstructure and thus the fatigue behavior at the temperature of the oral cavity. Conclusions: SlimShaper ZS2 and ZS3 showed significantly greater cyclic fatigue resistance than their PRO counterparts, while DSC analysis revealed distinct differences in phase transformation behavior that explain their mechanical performance. Full article

Objectives: The aim of this study was to investigate the relationship between the diameter of iatrogenic root perforations and the fracture resistance (FR) of endodontically treated teeth. Methods: Sixty-five single-rooted teeth were sectioned at 13 mm from the anatomic apex. Their weight and the mesiodistal (MD) and buccolingual (BL) dimensions were recorded in order to ensure their allocation into five homogeneous groups (N = 13); Group 1 (control group): teeth remained intact, Group 2: teeth were instrumented but not perforated, Group 3: teeth were instrumented and perforated with a 2.1 mm bur, Group 4: teeth were instrumented and perforated with a 1 mm bur, and Group 5: teeth were instrumented and perforated with a 0.5 mm bur. All perforations were created at the same spot in the buccal surface of the roots. To further standardize the defects, an apparatus ensured that the cutting bur was positioned with a steady angle of 105° to the external root surface. A universal testing machine was used for fracture testing by applying a compressive vertical load at a speed of 1 mm/min until root fracture. The recorded forces were statistically analyzed with one-way analysis of variance (ANOVA) and post hoc Tukey test. Results: The mean fracture load was 342.68 ± 146.45 N for Group 1, 322.96 ± 98.62 N for Group 2, 214.65 ± 71.32 N for Group 3, 212.66 ± 77.89 N for Group 4, and 307.14 ± 109.16 N for Group 5. However, only the differences between groups 1–3 and 1–4 were statistically significant (p < 0.05). Conclusions: The teeth with 2.1 mm and 1 mm perforations were found to have significantly decreased FR. Full article

Due to the complex anatomical structure of the distal humerus, elbow joint, and the soft tissue mantle (the triceps brachii muscle, large nerves, and vessels), fractures of the distal humerus and humeral condyle are difficult to treat. In most cases, strong instrumentation is needed to stabilize the fractures. To improve exposure of the distal humerus and humeral condyle, we proposed a caudolateral approach that involves elevating the anconeus muscle and splitting the triceps brachii. This study presents the results of using this approach in 16 canine cadavers. After exposing the distal humerus and maximally flexing the elbow joint, photographs were taken of the condyle from the same distance before and after olecranon osteotomy. The visible surface area of the articular cartilage was then calculated in square pixels after calibrating the photographs. It was possible to reach the distal and middle humerus in all cases. The only vital structure that could be easily identified and protected in all cadavers was the radial nerve. The visible area of the articular surface of the humeral condyle increased after olecranon osteotomy. The A₀ (visible area before osteotomy) was significantly smaller than the A₁ (visible area after osteotomy) in all dogs (p < 0.001). The ratio of A₀ to A₁ ranged from 57% to 67% in 15 dogs (median: 64%, interquartile range (IQR): 61–66%), with a very high value of 85% observed in one dog. This experiment used cadavers with intact elbows. This could limit the study’s findings because the effectiveness of the proposed access in reducing T-Y fractures was not assessed. The caudolateral approach is a valuable alternative to other methods for treating T-Y humeral fractures in dogs. Olecranon osteotomy widens access to the condyle. Further studies are needed to evaluate the necessity of olecranon osteotomy in clinical cases. Full article

This study analyzed how different downward loads and rotational kinematics influence NiTi rotary instrumentation outcomes. Heat-treated NiTi instruments were used to prepare extracted human single-rooted premolars with a moderate canal curvature. Instrumentation was performed using an automated endodontic instrumentation device with controlled downward loading and torque/force sensing, under different downward load settings (1, 2, and 3 N), employing either continuous rotation (CR) or optimum torque reverse (OTR) motion, which is a torque-sensitive reciprocation. Instrumentation was completed without instrument fracture or ledge formation in all six groups. OTR-3N specimens displayed a significantly lower upward force (i.e., screw-in force) than OTR-2N specimens (p < 0.05). OTR-1N specimens required a significantly longer instrumentation time than CR-1N specimens and the other OTR specimens (p < 0.05). At 1 mm from the apex, CR-2N specimens showed a significantly larger canal-centering ratio (i.e., larger deviation) than OTR-2N specimens (p < 0.05). Overall, applying a downward load of 2–3 N in OTR mode provided shaping efficiency similar to CR, but with a reduced screw-in force and enhanced canal-centering in the apical region, supporting the use of OTR as a promising alternative to CR for curved canal preparation using heat-treated NiTi instruments. Full article

Asymmetric friction, that is, different friction forces resisting sliding in opposing directions, works as a rectifier, transferring the applied oscillations into unidirectional motion. Locomotion of devices based on asymmetric friction is investigated by considering a model system consisting of an asymmetric friction block connected to a symmetric friction block by a spring. The symmetric friction block models the resistance to the movement by the environment. It is found that under harmonic oscillation, the system displays two distinct types of motion: Recurrent Movement (stick-slip-type movement) and Sub-Frictional Movement. The Recurrent Movement occurs when the inertia force is sufficient to overcome the frictional force. In this case, the system with asymmetric friction exhibits unidirectional locomotion, while the system with only symmetric friction oscillates about a fixed point. The Sub-Frictional Movement occurs when the inertia is insufficient to overcome the frictional force. Then the symmetric friction block moves against the asymmetric friction block and sufficiently loads the spring to enable some movement of the system. Thus, motion is generated even when the external forces are below the static friction threshold. These types of motion have been found to exhibit different types of spectral fallout: while the Recurrent Movement produces a typically observed frictional fallout 1/ω, where ω is the frequency, the Sub-Frictional Movement produces a stronger 1/ω² fallout, only observed in the development of an oblique fracture in rocks under compression. This discovery can shed light on mechanisms of rock failure in compression. Understanding of the unidirectional movement induced by asymmetric friction can be instrumental in designing novel locomotion devices that can move in narrow channels or fractures in the Earth’s crust or in extraterrestrial bodies utilising the (renewable) energy of external vibrations. Full article

Background and Objectives: Polypharmacy is common among older adults and its impact on the onset of dynapenia, reduced muscle strength and function, is largely unknown. Older adults hospitalized for either post-fracture or elective orthopedic surgery (knee, femur, or hip) and undergoing rehabilitation were included to investigate the association between polypharmacy and dynapenia. A further aim is to investigate associations between polypharmacy and dynapenia with outcomes including mortality, falls, and hospitalizations. Materials and Methods: On the fifth day following surgery, medical doctors administered a structured questionnaire along with physical and instrumental assessments. Polypharmacy was defined as the concurrent and regular use of 5 or more medications, dynapenia was assessed by measuring handgrip strength. The association between dynapenia and polypharmacy was detected with logistic regression, and their impact on adverse outcomes was assessed using Cox models, Kaplan–Meier curves and log-rank tests. Results: A total of 205 older adults (mean age 77.5 years; 79.5% women) were enrolled. After adjusting for sex, age, and the presence of multidimensional frailty, dynapenia was significantly associated with increased adverse outcomes such as mortality, falls, and hospitalizations (HR 2.96, 95% CI 1.22–7.20, p = 0.016). Similarly, polypharmacy was independently linked to a higher risk of mortality, falls and hospitalizations (HR 2.23, 95% CI 1.24–4.10, p = 0.007). At 6 months follow-up, polypharmacy showed a strong and significant association with dynapenia (adjusted OR 2.63, 95% CI 1.21–4.63, p = 0.019). Conclusions: These findings suggest that polypharmacy is strongly associated with dynapenia, both conditions are associated with adverse clinical outcomes in older hospitalized patients. Close monitoring and tailored interventions are recommended to mitigate these risks and improve rehabilitation outcomes in this vulnerable population. Full article

Frailty has emerged as a critical determinant of clinical outcomes in elderly patients, shaping postoperative recovery in crucial orthopedic events, such as hip fractures. The purpose of the present study is to examine the impact of frailty syndrome on muscle strength and joint range of motion in the non-fractured lower extremity and upper extremities of hospitalized older adults following hip fracture surgery. The sample consisted of 60 elderly patients recovering from either intracapsular or extracapsular hip fractures. Participants were categorized into either a frail or non-frail group, determined by the Clinical Frailty Scale. The outcome measures of muscle strength and range of motion of the upper and lower extremities were assessed by valid instruments, including a hand-held dynamometer, the Medical Research Council scale, and a digital goniometer. Statistical comparisons between groups were conducted using the independent samples t-test and the Mann–Whitney U test. The results showed that the non-frail group demonstrated greater active range of motion in the shoulder bilaterally (right: t = −2.85, left: U = 628.00, p < 0.05), elbow flexion bilaterally (right: U = 589.50, left: U = 592.50, p < 0.05), hip flexion (U = 679.50, p < 0.01), knee extension (t = −3.07, p < 0.05), and ankle dorsiflexion (t = −2.36, p < 0.05). Regarding the muscle strength, the non-frail group showed significantly higher grip strength bilaterally (right: U = 754.50, left: U = 713.50, p < 0.001), as well as greater strength in hip flexion (U = 641.00, p < 0.01) and ankle dorsiflexion (U = 619.50, p < 0.01). Frailty may negatively influence the muscle strength and joint mobility in non-fractured extremities, thereby hindering postoperative physical recovery in older adults with hip fractures. Further research involving a larger and more homogeneous sample may predict falls in elderly patients after hip or knee surgery using the Clinical Frailty Scale. Full article

This study examines Phase B of the GREENERGY project focusing on the seismic performance and structural health monitoring of a renovated single-story RC frame with brick masonry infills that received significant strategic structural interventions. The columns were confined with basalt fiber ropes (FR, 4 mm thickness, two layers) in critical regions, the vertical interfaces between infill and concrete were filled with polyurethane PM forming PUFJ (PolyUrethane Flexible Joints), and glass fiber mesh embedded in polyurethane PS was applied as FRPU (Fiber Reinforced PolyUrethane) jacket on the infills. Further, greenery renovations included the attachment of five double-stack concrete planters (each weighing 153 kg) with different support-anchoring configurations and of eight steel frame constructions (40 kg/m²) simulating vertical living walls (VLW) with eight different connection methods. The specimen was subjected to progressively increasing earthquake excitation based on the Thessaloniki 1978 earthquake record with peak ground acceleration ranging from EQ0.07 g to EQ1.40 g. Comprehensive instrumentation included twelve accelerometers, eight draw wire sensors, twenty-two strain gauges, and a network of sixty-one PZTs utilizing the EMI (Electromechanical Impedance) technique. Results demonstrated that the structure sustained extremely high displacement drift levels of 2.62% at EQ1.40 g while maintaining structural integrity and avoiding collapse. The PUFJ and FRPU systems maintained their integrity throughout all excitations, with limited FRPU fracture only locally at extreme crushing zones of two opposite bottom bricks. Columns’ longitudinal reinforcement entered yielding and strain hardening at top and bottom critical regions provided the FR confinement. VLW frames exhibited equally remarkably resilient performance, avoiding collapse despite local anchor degradation in some investigated cases. The planter performance varied significantly, yet avoiding overturning in all cases. Steel rod anchored planter demonstrated superior performance while simply supported configurations on polyurethane pads exhibited significant rocking and base sliding displacement of ±4 cm at maximum intensity. PZT structural health monitoring (SHM) sensors successfully tracked damage progression. RMSD indices of PZT recordings provided quantifiable damage assessment. Elevated RMSD values corresponded well to visually observed local damages while lower RMSD values in columns 1 and 2 compared with columns 3 and 4 suggested that basalt rope wrapping together with PUFJ and FRPU jacketed infills in two directions could restrict concrete core disintegration more effectively. The experiments validate the advanced structural interventions and vertical forest renovations, ensuring human life protection during successive extreme EQ excitations of deficient existing building stock. Full article

Premixed bioceramic sealers represent a recent advancement in endodontic obturation, combining bioactivity, moisture-induced mineralization and favorable handling properties. When used with warm gutta-percha techniques, these calcium silicate-based sealers are exposed to elevated temperatures that may influence their physicochemical behavior and interfacial performance. This review aimed to summarize current evidence on premixed bioceramic sealers used in conjunction with thermoplastic obturation techniques. A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science for studies published between January 2020 and July 2025 evaluating the physicochemical properties, bioactivity, sealing ability, fracture resistance, clinical outcomes and retreatability of premixed bioceramic sealers under warm obturation conditions. No meta-analysis was performed—this review provides a narrative synthesis of the available evidence within this scope. Twenty-five studies met the inclusion criteria. In vitro and ex vivo data indicate that premixed bioceramic sealers generally maintain chemical stability and bioactivity when exposed to clinically relevant heating protocols, with favorable dentinal tubule penetration, interfacial adaptation and the formation of calcium silicate hydrate, and hydroxyapatite at the sealer–dentin interface. These characteristics are associated with improved filling homogeneity, potential reinforcement of root dentin and high rates of periapical healing reported in limited short-term clinical studies. However, the evidence also highlights important challenges, including technique-sensitive retreatability, material remnants after re-instrumentation and concerns regarding overextension, and long-term dimensional stability. Within the limitations of predominantly in vitro and short-term clinical evidence, premixed bioceramic sealers used with warm gutta-percha techniques appear to be promising functional materials that combine mechanical sealing with bioactive and mineralizing potential. Standardized protocols and robust long-term clinical studies are needed to confirm their durability, retreatability and prognostic impact in routine endodontic practice. Full article

Background/Objectives: Vitamin D deficiency contributes to pathological vertebral fragility (path-VF), including fragility fractures and early pedicle screw loosening after posterior instrumented spinal fusion (PISF). Supplementation practices remain inconsistent. This retrospective study evaluated whether patients with path-VF receive appropriate vitamin D3 (Vit.D3) supplementation and assessed the dose–response relationship between daily intake and path-VF risk, particularly in older adults. Methods: A total of 210 patients treated with kyphoplasty or PISF (2022–2023) were classified into a path-VF or control group. Daily oral Vit.D3 intake was categorised as Zero- (0 IU), Low- (<2000 IU), or High-Dose (≥2000 IU). Statistical analyses were performed for each dosage group, including subgroup analyses for patients aged ≥67.5 years. Vertebral BMD was estimated using mean Hounsfield Units (HU) from T11–L5. Results: Patients in the path-VF group received significantly lower Vit.D3 doses than controls (1431.4 ± 1055.7 vs. 2366.7 ± 1186.7 IU/day, p < 0.001). Low-dose supplementation was associated with a markedly increased risk of path-VF compared with high-dose in the overall cohort (OR = 6.5, p = 0.003) and in patients aged ≥67.5 years (OR = 8.6, p = 0.008). Logistic regression identified a threshold of 1900 IU/day (AUC = 0.805). Mean vertebral HU values were significantly lower in the path-VF group than in controls (71.9 ± 29.1 vs. 133.5 ± 52.6, p < 0.001), and no consistent HU gains were observed with increasing Vit.D3 dosage. Conclusions: Low-dose Vit.D3 supplementation was associated with increased path-VF risk, especially in patients aged >67.5 years. Patients without path-VF had received significantly higher doses, suggesting broader benefits of adequate Vit.D3 beyond bone density. A daily intake above 1900 IU may serve as a practical threshold for at-risk elderly patients. Full article

Background/Objectives: Distal radius fractures are common upper extremity injuries requiring reliable outcome measures for accurate clinical assessment. This study aimed to validate the Croatian versions of the Disabilities of the Arm, Shoulder and Hand (DASH), Patient-Rated Wrist Evaluation (PRWE), and Mayo Wrist Score (MWS) in patients with distal radius fractures. Methods: DASH, PRWE, and MWS Croatian versions were evaluated in 128 patients using standardized translation, cultural adaptation, factor analysis, and internal consistency (Cronbach’s α). Results: PRWE-Cro and DASH-Cro demonstrated excellent validity and internal consistency (α > 0.95). QuickDASH-Cro showed high reliability and is recommended as a practical alternative. MWS was validated for the first time, showing good validity and acceptable internal consistency (α = 0.71). Conclusions: PRWE-Cro and DASH-Cro are validated, reliable instruments suitable for both clinical practice and research in Croatian-speaking populations while MWS can be used as a quick screening tool. Full article

EMFIT, also referred to as EMFi, is a ferroelectret film related to polyvinylidene fluoride (PVDF) sensors. It is an electroactive polymer (EAP) based on a polyolefin structure and consists of three layers of polyester film. Its application in geophysical monitoring has not been reported in the literature. At present, EMFIT is mainly employed in ballistocardiography and medical sleep monitoring, as developed by the manufacturer Emfit Ltd. (Vaajakoski, Finland). Within the multidisciplinary monitoring network of the National Institute for Earth Physics (NIEP), EMFIT is used as a pressure sensor in combination with infrasound transducers and microphones deployed in seismic areas. The primary aim of this study is to evaluate its suitability for detecting seismic noise that precedes earthquakes, generated by rock fracturing associated with crustal deformation. Although similar studies have been reported, they have not involved the use of EMFIT sensors. The novelty of this approach lies in the large surface area and mechanical flexibility of the material. Beyond seismic forecasting, the research also examines whether this type of sensor can contribute to seismic monitoring as a complement to conventional instruments such as accelerometers, seismometers, and microbarometers. Data analysis relies primarily on spectral time-series methods and incorporates measurements from other acoustic sensors (microphones and microbarometers) as well as a weather station. The working hypothesis is the potential correlation between the recorded data and the presence of enhanced noise prior to the detection of seismic waves by standard seismic sensors. The target area for this investigation is Vrancea, specifically the Vrâncioaia seismic station, where multidisciplinary monitoring includes infrasound, radon, thoron, soil temperature, and atmospheric electrical discharges. Preliminary tests suggest that the EMFIT sensor may function as a highly sensitive device, effectively serving as an “ear” for detecting ground noise. Full article

Objective: To assess the predictive value of systemic inflammatory markers for postoperative complications in older adults undergoing posterior spinal instrumentation for either lumbar spinal stenosis (LSS) or osteoporotic vertebral fractures (OVFs). This study design as a retrospective observational study. Methods: Fifty-four patients aged ≥ 55 years who underwent posterior spinal instrumentation between 2020 and 2023 were retrospectively analyzed. Patients were grouped into LSS (n = 27) and OVF (n = 27) cohorts. Preoperative, early postoperative, and 6-month follow-up systemic inflammatory marker levels, including the Systemic Inflammatory Response Index (SIRI), Systemic Immune-Inflammation Index (SII), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Monocyte-to-Lymphocyte Ratio (MLR), were recorded. The primary outcome was the occurrence of postoperative infectious complications. ROC curve analysis was conducted to evaluate the discriminatory power of each marker. Results: SIRI values were significantly higher in the OVF group than in the LSS group at all time points (p < 0.05). Postoperative complications occurred in 7.4% of patients, equally distributed between groups. ROC analysis showed that preoperative SIRI had the highest predictive value (AUC = 0.743), with a cutoff value of 2.69 yielding 100% sensitivity and 65.3% specificity. Other indices showed poor predictive accuracy (AUC < 0.70). Conclusions: Preoperative SIRI is a promising, easily obtainable biomarker for identifying older patients at higher risk of postoperative complications following posterior spinal instrumentation. Its implementation may improve preoperative risk stratification in spine surgery. Full article

Sapphire crystals, owing to their outstanding mechanical and optical properties, which are widely used in advanced optics, microelectronic devices, and medical instruments. The manufacturing precision of sapphire optical components critically affects the performance of advanced optical systems. However, the extremely high hardness and low fracture toughness of sapphire make it a typical hard-to-machine material, prone to brittle surface fractures and subsurface damage during material removal. Improving the machinability of sapphire remains a pressing challenge in advanced manufacturing. In this study, surface modification and enhanced ductility of C-plane sapphire were achieved via ion implantation, and the machinability of the modified sapphire was further improved through laser-assisted diamond machining (LADM). Monte Carlo simulations were employed to investigate the interaction mechanisms between incident ions and the target material. Based on the simulation results, phosphorus ion implantation experiments were conducted, and transmission electron microscopy observation was used to characterize the microstructural evolution of the modified layer, while the optical properties of the samples before and after modification were analyzed. Finally, groove cutting experiments verified the enhancement in ductile machinability of the modified sapphire under LADM. At a laser power of 16 W, the ductile–brittle transition depth of the modified sapphire increased to 450.67 nm, representing a 51.57% improvement over conventional cutting. The findings of this study provide valuable insights for improving the ductile machining performance of hard and brittle materials. Full article

Telerehabilitation is an effective, accessible addition or alternative to conventional rehabilitation for fracture management, especially in older adults after hip fractures, leveraging video visits, mHealth apps, virtual reality (VR), and wearable sensors to deliver exercise, education, and monitoring at home with high satisfaction and adherence. Across non-surgical and surgical contexts, telemedicine shows feasibility and cost benefits, with mixed superiority but consistent non-inferiority for functional outcomes versus in-person care. In hip fracture populations, randomized and non-randomized studies indicate improvements in functional independence measure (FIM), Timed Up and Go test (TUG), Activities of Daily Living/Instrumental Activities of Daily Living (ADLs/IADLs), and quality of life, with some evidence for reduced anxiety and depression, while effects on mobility, pain, and adverse events remain uncertain overall. In patients with upper-limb fractures, telerehabilitation appears to improve function and pain, though strength gains may lag compared with in-person therapy in some trials; adjuncts like motor imagery and virtual reality may enhance outcomes and motivation. Application is facilitated by user-friendly platforms, caregiver involvement, and simple modalities such as structured phone follow-up. Limitations include small samples, heterogeneous protocols, scarce long-term data, and a predominance of non-inferiority or complementary designs, warranting larger, definitive trials. This technology can lead to improved patient management at home, effortlessly verifying treatment compliance, efficacy, and safety, while simultaneously reducing the need for hospitalization, promoting a more peaceful recovery. Here, we have undertaken a narrative review of the medical–scientific literature in this field. Full article