A relationship of tightening torque and initial load of dental implant of nano bio-silica and bamboo fiber-reinforced bio-composite material.

Due to entry of body fluid like saliva, blood, etc. in the dental implant assembly lowers the preload value, thus dental implant abutment tightening torque loses. In this article a novel chitosan-reinforced bamboo and nano bio-silica-reinforced five composite materials (CP, CF, C1, C2, and C3) are fabricated using the hand layup method, and their mechanical, biocompatible, and moisture absorption properties are observed and discussed. The present study examines the impact of friction and Young's modulus on the correlation between torque and starting load in dental implant abutment screws, utilizing the attributes of a bio-composite material. C2 bio-composite composite material exhibits the highest tensile strength (139.442 MPa), flexural strength (183.571 MPa), compressive strength (62.78 MPa), and a minimum value of 1.35% absorption of water. C3 is tested with no cytotoxicity, while C3 and CF exhibit weak biofilm resistance against S. aureus gram-positive bacteria. The C2 bio-composite material demonstrated a maximum initial load of 20 N with a tightening torque of 20 N-cm, under both 0.12 and 0.16 coefficients of friction. The simulated results were compared with several theoretical relations of torque and initial load and found that the Motos equation holds the nearest result to the obtained preload value from finite element analysis. Overall, the experimental findings suggest that the C2 bio-composite material holds significant potential as a prominent material for dental implants or fixtures.

3D Printed customized diabetic foot insoles with architecture designed lattice structures - a case study.

This study proposes a 3D printed, custom insole using an architectural lattice structure infill targeting diabetic patients at risk of foot ulcers. An analysis of five lattice configurations: Fluorite, Kelvin, Octet, Isotruss unit cells, and Truncated Octahedron was conducted to identify the most effective insole infill for plantar pressure and weight redistribution. The Kelvin lattice demonstrated minimal stiffness, suggesting its superiority in balancing plantar pressure and weight. Such lattice-structured insoles offer enhanced foot support and cushioning, crucial for ulcer-prone individuals. This research innovatively employs architectural lattice structures in designing insoles for diabetic patients, offering an insightful comparison of lattice designs for optimized foot care.

An Optimized Dental Implant Model Using Finite Element Analysis and Design of Experiment.

Purpose: To develop, analyze, and optimize a dental implant by considering square threads and varying the thread dimensions to obtain an optimal shape. Materials and Methods: For this study, finite element analysis (FEA) and numerical optimization method were integrated to develop a mathematical model. The critical parameters of dental implants were studied, and an optimized shape was obtained using response surface method (RSM) and design of experiment (DOE). The simulated results were then compared to the predicted values under optimal conditions. Results: Using the one-factor RSM design model for the dental implant and a vertical compressive load of 450 N for testing, the optimal depth to width ratio for the thread was 0.7 in order to achieve the minimum von Mises and shear stress. Conclusion: The buttress thread was found to be the optimal shape for achieving the lowest von Mises and shear stress compared to square threads, and the thread parameters were calculated accordingly, with a thread depth 0.45 times the pitch, a width 0.3 times the pitch, and a thread angle of 17 degrees. Also, due to the constant diameter of the implant, common 4-mm diameter abutments can be used interchangeably.

Characterization of raw and alkali treated cellulosic Grewia Flavescens natural fiber.

The physicochemical, mechanical, thermal as well as morphological characteristics of alkali treated cellulosic Grewia Flavescens are reported in this paper. Using standard test methods, the chemical constituents of Grewia Flavescens fiber (GFF) are evaluated. Fiber treated in 5% (w/v) NaOH for 45 min soaking time is regarded as optimally surface-modified fiber. After optimal alkalization, there is an enhancement of cellulose content from 58.46% to 68.31%. Mechanical properties of GFF are determined by single fiber tensile test and improved tensile strength is achieved after alkalization. Weibull statistical analysis is performed for diameter and mechanical parameters of raw as well as treated GFF. FTIR spectroscopy reveals the removal of amorphous material from the fiber post-treatment and XRD analysis confirms improvement in crystallinity index from 16.01% to 26.72% and crystal size from 62.90 nm to 68.43 nm after alkalization. Thermal stability and thermal degradation temperature are found to be improved after alkali treatment. Morphological analysis of raw and alkali treated cellulosic GFF shows enhanced rough surface of fiber after alkalization because of elimination of impurities and foreign particles from the fiber surface. Presently studied GFF seems to be a good substitute to the harmful man-made fibers for making of bio composites.

Synthesis of diamond crystal growth on tungsten carbide inserts by HFCVD using various seeding powders.

The hot filament chemical vapor deposition (HFCVD) process is used to synthesize diamond crystals on cemented carbide (WC-Co) SPUN inserts. Diamond (Dia.), carbon (GC-glassy spherical form), iridium (Ir), molybdenum (Mo), palladium (Pd), platinum (Pt), tungsten (W), and tantalum (Ta) powders were used as seeding materials for crystal growth. Scanning electron microscopy (SEM) data revealed the development of a few diamond crystals in platinum, iridium, and tungsten powders. The seeding with carbon, tantalum, and diamond powders formed clustered microcrystalline diamond (MCD) crystals, although other powders produced discrete crystals. Tantalum and diamond-seeded powders produced the most significant number and size of crystals. According to micro-Raman spectroscopy (µ-RS), tantalum powder had the lowest I D/I G ratio and the most excellent sp 3 bonding. X-ray diffraction (XRD) revealed the maximum diamond intensity in the (111) plane. According to atomic force microscopy (AFM), diamond and molybdenum powders had the largest grains, whereas tantalum powder had the smallest root mean square roughness value with a homogeneous grain distribution. The Vickers microhardness (VHN) test confirmed the highest hardness value for diamond and tantalum seeded powder coatings with the least amount of radial cracking. Field emission scanning electron microscopy (FESEM) revealed that both powders had higher film thickness values.