Dental erosion potential of beverages and bottled drinking water in Bangladesh

Dental erosion is a growing health problem linked to the exceptional increase in the consumption of soft drinks, fruit juices, and sport drinks in many countries including Bangladesh. Dental erosion is the chemical dissolution of the dental hard tissues by acids without the involvement of microorganisms. Hydrogen ions (H⁺) from acidic solutions can replace the calcium ions (Ca²⁺) of the enamel, consequently breaking the crystal structure of the enamel and initiating dental erosion. Erosive tooth wear can lead to severe impairment of esthetics along with loss of hardness and functionality. Sources of the erosive acidic challenges can be intrinsic (i.e., gastroesophaegal reflux disease) and/or extrinsic (i.e., exposure from acidic foods and beverages). Continuous intake of drinks or food with pH lower than the critical erosive pH of enamel (5.2–5.5) and root dentin (~6.7) are considered to be responsible for dental erosion. Drinks with low pH and high titratable acidity (TA) have more potential to dissolved enamel and root dentin; on the other hand, drinks with low degree of saturation can stimulate leaching of minerals. In Bangladesh, there is limited scientific information available to assess the potential of dental erosion of the commercially available beverages and drinking water. This research aims to characterize the dental erosion potential of soft drinks, energy drinks, fruit juices, and bottled drinking water available in Bangladesh by determining their pH, TA, calcium (Ca²⁺), and phosphate (PO₄^3?). The degrees of saturation of the selected samples were calculated from the experimental results of pH, calcium, and phosphate levels. Soft drinks were found to have high erosion potential followed by energy drinks, fruit juices, and bottled drinking water. Most of the beverages locally available were found highly acidic. Phosphate levels were high in black cola drinks. Total TA was highest for the energy drinks, and moderate for soft drinks and fruit juices. Fruit juices contained high level of calcium compared with other beverages. The degree of saturation was moderate for fruit juices, and very low for few of the soft drinks and most of the bottled drinking waters. This study will be useful as a reference line for the health professionals and regulatory authorities for quality control of the beverages and bottled drinking water available in the local market.     

Structural,morphological, optical and electrical properties of spray deposited zinc doped copper oxide thin films

Nanostructured spray deposited zinc (Zn) doped copper oxide (CuO) thin films were characterized by employing X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) and ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy. XRD patterns of CuO and Zn doped CuO thin films indicated monoclinic structure with the preferred orientation along \(\left( {\bar 111} \right)\) plane. Maximum value of crystallite size is found about 28.24 nm for 5 at% Zn doped CuO thin film. In FESEM images, nanoparticles were observed around the nucleation center. EDX analysis confirms the presence of all component elements in CuO and Zn doped CuO thin films. Analysis by AFM of CuO and Zn doped CuO thin films figured out decrease of surface roughness due to Zn doping. UV–Vis–NIR spectroscopy showed that CuO and Zn doped CuO thin films are highly transparent in the NIR region. Optical band gap of CuO thin films decreased with substrate temperature and that of Zn doped CuO thin films increased with Zn concentration. Refractive index of CuO and Zn doped CuO thin films raised with photon wavelength and became constant in the NIR region. 5 at% Zn doped CuO thin film showed the highest optical conductivity and the lowest electrical resistivity at room temperature.     

The environmental stability of boron-containing titanium alloys for biomedical applications

Musculoskeletal and craniofacial implants, and their interactions with the human body, are a very important area of medicine today. Aging populations and rapidly escalating health care costs make the study of implant-body interactions increasingly urgent. One of the major impediments to long-term durability of implant materials is the issue of aseptic loosening, i.e., inflammatory response against the prosthetic metal and metal debris produced by its corrosion. In this research summary, we discuss the corrosion behavior of a new class of boron-containing titanium alloys in physiologically relevant media. In addition, the suitability of these alloys from a mechanical perspective will also be discussed along with implications for alloy design.     

Evaluation of Synurus deltoides for antioxidant,antimicrobial, and anti-proliferative activities using In vitro assays

The antioxidant, antimicrobial, and anti-proliferative activities of water and ethanol extracts from leaves of Synurus deltoides (SD) were investigated. Extracts showed strong reductive powers, nitrite-scavenging activities, DPPH, ABTS, hydroxyl, and superoxide radical scavenging activities, and DNA damage prevention activities. SD extracts also showed strong cellular antioxidant activities in a dose-dependent manner with IC₅₀ values of 0.93 and 0.65 mg/mL for water and ethanol extracts, respectively. Antimicrobial activities were evaluated against 4 microorganisms. SD extracts showed high inhibitory activities against Pseudomonas aeruginosa and Staphylococcus aureus. The anti-proliferative activity was dose-dependent against human colon adenocarcinoma (HT-29) and mouse rectum carcinoma cells (CMT-93). In addition, HPLC analyses of SD leaf extracts revealed the presence of different phenolic compounds. SD can be considered as a source of functional foods and pharmaceuticals.     

Comparative analysis and antibacterial properties of thermally sintered apatites with varied processing conditions

Hydroxyapatite (HA) and biphasic hydroxyapatite/beta-tricalcium phosphate (biphasic HA/β-TCP) were synthesized using thermal sintering. The parameters- sintering temperature (600°C, 900°C, and 1200°C), biological source used (fish bone, egg shells, and fish scales), and soaking time (2, 6, and 10 hours) were permuted to study their effects on the properties of the resultant apatite. Morphological study revealed that the smallest (60 nm) spherical particle and the largest (470 nm) irregular shaped particle were obtained from the fish bone sample sintered at 600°C and at 1200°C respectively. FTIR and XRD results showed that as the sintering temperature is increased, the phase transformation from HA to β-TCP takes place. Only the final products from fishbone sample at 600°C are pure carbonated HA. The crystallinity of synthesized particles ranged from 79% to 98%. Soaking time has no effect on phase composition of the apatite but has significant effect on crystallite size; increase in soaking time increases crystallite size and particle shape becomes more spherical. Interestingly, the fish bone sample sintered at 900°C has higher crystallinity and crystallite size compared to the fish scale sample sintered at the same temperature. EDX confirmed that non-stoichiometric apatite with Ca/P ratio ranging from 1.47 to 1.91 can be obtained by varying the sintering conditions. The antibacterial test revealed that both calcium apatite obtained from fish bones and fish scales have inhibited bacterial growth; apatite from fish bone works faster than fish scales. The in vitro cytotoxicity test ensured that all the calcium apatite except for eggshell are non-cytotoxic. Thus, apatite with excellent microbial activity can be obtained by using fish wastes, and by tuning the sintering parameters, the apatite with desired types and properties can be synthesized for different biomedical applications.