Currently, polymethylmethacrylate (PMMA) is the most popular denture base material. Most fractures of dentures that occur during function are due to its insufficient mechanical strength. The major drawbacks of PMMA are insufficient ductility, strength, and viscoelastic behavior. The purpose of this study was to evaluate a polymethylmethacrylate denture base material modified with TiO₂ nanoparticles in terms of nanomechanical, creep-recovery, and relaxation. Additionally, the effects of addition TiO₂ nanoparticles on the thermal and antimicrobial adhesion behaviors were investigated. Differential scanning calorimetry and thermogravimetric analysis indicated that the effect of small amounts of TiO₂ nanoparticles (1 wt. %, 2 wt. %, and 3 wt. %) on the degradation behavior of PMMA denture bases was insignificant. The nanomechanical test results of the PMMA and PMMA/TiO₂ nanocomposites indicated that the hardness and modulus in the nanoscale range improved due to TiO₂ addition. At a 1200-nm penetration depth, the modulus increased by 10%, 16%, and 29% and hardness increased by 18%, 24%, and 35% with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. Furthermore, the creep-recovery and relaxation behaviors of PMMA were significantly improved due to the addition of TiO₂. The creep strain decreased from 1.41% to 1.06%, 0.66%, and 0.49% with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. The relaxation test results showed that the initial stress under 1% strain improved to 19.9, 21.2, and 22 MPa with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. The improvement in the nanohardness, modulus, creep recovery, and relaxation behavior of PMMA due to the addition of TiO₂ nanoparticles indicated the role of the nanoparticles in increasing the PMMA matrix stiffness by reducing its mobility and free volume. TiO₂ nanoparticles also improved the antimicrobial behavior of PMMA by significantly reducing bacterial adherence with increasing TiO₂ ratio.

Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.

Background: COVID-19 vaccines were made available to the public by the end of 2020. However, little is known about COVID-19 booster dose (CBD) vaccine perception among healthcare workers (HCW) worldwide. The present study aims to assess the perception of CBD vaccines among healthcare workers in India and Saudi Arabia (SA). Methods: A cross-sectional study was conducted among HCWs in two countries, India and SA. Data were gathered through the use of a self-administered questionnaire. A convenience sampling technique was utilized to collect the data. Results: A total of 833 HCW responses were collected from the two countries, with 530 participants from India and 303 participants from SA responding to the questionnaire. Among them, 16% from India and 33% from SA were unwilling to take a CBD (p < 0.005). The primary reasons for not being willing were concerns about whether the vaccine would be effective (32%) and concerns about probable long-term side effects (31%). Concerns about not knowing enough about the vaccination (30%) and the possibility of long-term side effects (28%) were the primary concerns in SA. Regression analysis showed that males, urban residents, and post-graduates were more willing to take the CBD. Conclusion: There is a good perception of CBD and some hesitancy in receiving the booster dose among HCWs in both countries. The introduction of personalized education, risk communication, and deliberate policy could help to reduce the number of people who are unwilling to take a booster shot.

Syzgium cumini (L.) Skeels powder (S. cumini powder), also known as Jamun, is well-known for its various medical and health benefits. It is especially recognized for its antidiabetic and antioxidant properties. Thus, S. cumini powder is used in various industries, such as the food and cosmetic industries. In this work, the fruit of S. cumini was utilized; its seeds were extracted, dried, and ground into powder. The ground powders were subjected to various techniques such as physicochemical tests, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), particle size analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antioxidant analysis. From the physicochemical tests, it was revealed that the jamun seed filler contained cellulose (43.28%), hemicellulose (19.88%), lignin (23.28%), pectin (12.58%), and wax (0.98%). The FTIR analysis supported these results. For instance, a peak at 2889 cm⁻¹ was observed and associated with CH stretching, typically found in methyl and methylene groups, characteristic of cellulose and hemicellulose structures. The XRD results demonstrated that the crystallinity index of the jamun seed filler was 42.63%. The particle analysis indicated that the mean (average) particle size was 25.34 μm. This observation was ensured with SEM results. The EDX spectrum results showed the elemental composition of the fillers. Regarding thermal degradation, the jamun seed filler had the ability to withstand temperatures of up to 316.5 °C. Furthermore, endothermic and exothermic peaks were observed at 305 °C and 400 °C, respectively. Furthermore, the antioxidant property of the powder displayed a peak scavenging activity of 91.4%. This comprehensive study not only underscores the viability of S. cumini powder as a sustainable and effective particulate filler in polymer composites but also demonstrates its potential to enhance the mechanical properties of composites, thereby offering significant implications for the development of eco-friendly materials in various industrial applications.

This study evaluated dental implant stability, vertical bone gain, bone density, and crestal bone loss using different crestal sinus lift techniques (osteotomy, Densah burs, and piezosurgery). A total of 21 patients were randomly divided into three groups: Group 1: patients were treated using a Densah drill crestal sinus lift, Group 2: patients were treated using a piezoelectric crestal sinus lift and Group 3: patients were treated using an osteotome crestal sinus lift. The patients in all three groups underwent bone grafting and implant placement. An Osstell device was used to determine the implant stability by recording the values of the implant stability quotient (ISQ). CBCT was performed before and 6 months after implant placement for radiographic evaluation and comparison among the groups. All dental implants were completely successful, and statistically significant differences from baseline to 6 months were noted in all groups (p < 0.05). The Densah burs technique resulted in the best implant stability of all groups, while the osteotome technique demonstrated better vertical bone augmentation. However, the values for bone density and crestal bone loss showed no significant difference among all treated groups (p > 0.05). All three techniques were successful for crestal sinus lifts with good clinical outcomes at a 6-month follow-up. The Densah group demonstrated better implant stability, shorter surgery time, and fewer complications; however, the vertical bone gain was greater with the osteotome technique.