Isfahan general dentist's awareness, attitude, and performance regarding prescription of new caries prevention materials containing calcium and fluoride components

BACKGROUND

Fluoride Ion can cause remineralization of primary caries lesions in the presence of calcium and phosphate. New compounds of calcium-containing casein phosphopeptides-amorphous calcium phosphate (CPP-ACP), make the remineralization more effective. This research has been done to evaluate the awareness, attitude, and performance of Isfahan general dentists regarding the prescription of new caries prevention materials containing calcium and fluoride components.

MATERIALS AND METHODS

This cross-sectional-descriptive-analytic study has been conducted on 152 general dentists in Isfahan ensuring confidentiality of information and obtaining informed consent. Isfahan general dental offices and clinics were selected using a simple random method. Data of this research were collected using a questionnaire from previous studies. The questions were divided into four sections, including demographic information, awareness, attitude, and performance towards products containing calcium and fluoride prescription. The significance level of P was considered 0.05. Data were analyzed using SPSS version 22, T statistical test, Pearson correlation coefficient, and one-way analysis of variance.

RESULTS

The mean score for dentists awareness was 46.3 (standard deviation [SD] = 15.4), the mean score of attitude was 91.4 (SD = 26.1) and the Mean Score of performance was 54.3 (SD = 27.3) (the scores range from 0 to 100). According to the Pearson correlation coefficient, there was no significant relationship between dentists' awareness, attitude besides performance, and their ages together with dentistry work experiences (P > 0.05).

CONCLUSION

According to the study results, dentists' awareness of compounds containing CPP-ACP is overall average. However, attending to their positive attitudes toward this context, providing appropriate training programs seem to stimulate them for optimum cooperation as well as using these products for patients.

Radiation-Induced Nucleation and Growth of CaSi2 Crystals, Both Directly during the Epitaxial CaF2 Growth and after the CaF2 Film Formation

The radiation-induced phenomena of CaSi2 crystal growth were investigated, both directly during the epitaxial CaF2 growth on Si (111) and film irradiation with fast electrons on Si (111) after its formation, while maintaining the specified film thickness, substrate temperature and radiation dose. Irradiation in the process of the epitaxial CaF2 film growth leads to the formation of CaSi2 nanowhiskers with an average size of 5 µm oriented along the direction <110>. The electron irradiation of the formed film, under similar conditions, leads to the homogeneous nucleation of CaSi2 crystals and their proliferation as inclusions in the CaF2 film. It is shown that both approaches lead to the formation of CaSi2 crystals of the 3R polymorph in the irradiated region of a 10 nm thick CaF2 layer.

Effect of Calcium Compound Type and Dosage on the Properties of Acid Rennet Goat's Milk Gels

The aim of this study was to determine the effect of adding calcium compounds to processed goat’s milk, and on the properties of acid rennet goat’s milk gels, which are a middle product obtained in the manufacture of acid rennet cheese. The properties of the gels directly affect the quality of acid rennet cheeses. The analysis of raw goat’s milk was carried out, then acid rennet gels were produced with the addition of six different calcium compounds (chloride, citrate, bisglycinate, gluconate, lactate, and carbonate). The dynamics of milk fermentation were performed by monitoring the pH value of milk during acidification. The pH, syneresis, color, and texture profile were determined in the formulated acid rennet gels. An organoleptic evaluation was also performed. The study demonstrated that, not only calcium chloride, but also calcium citrate, gluconate, lactate, bisglycinate, and calcium carbonate could be used in the production of goat’s milk acid rennet gels, or the middle product in the manufacture of acid rennet curd cheese from goat’s milk. Notably, the addition of citrate, bisglycinate, and calcium carbonate in doses of 20 mg Ca 100 g⁻¹ most effectively reduced syneresis compared to the control sample by 4.76% (citrate), 7.85% (bisglycinate), and 10.28% (carbonate). The hardness of the control gels ranged from 2.35 N to 2.99 N. The addition of chloride, citrate, gluconate, lactate, and calcium carbonate to the milk improved the acid rennet gel’s hardness. The addition of 20 mg Ca 100 g⁻¹ as gluconate increased the hardness the most (3.61 N). When increasing the calcium dosage in the form of all compounds, there was a tendency to increase the gel’s springiness. The addition of chloride, citrate, and bisglycinate to milk did not result in a darkening of the gel’s color. The addition of calcium compounds mostly reduced the intensity of goatish taste and odor. Calcium gluconate, in particular, reduced the goatish taste the most, a taste which is not always acceptable by the consumers.

Biological and mechanical evaluation of mineralized-hydrogel scaffolds for tissue engineering applications

Chitosan and gelatin have been extensively used in tissue engineering for a wide range of different applications, such as wound healing or bone regeneration, due to their advantages: excellent biocompatibility (promoting cell adhesion and proliferation), low price and biodegradability. Nonetheless, their main drawback is that they have poor mechanical properties, consequently restricting their use in bone tissue engineering. In previous studies, both materials were cross-linked, with added calcium minerals, which led to an improvement in both mechanical and biological properties. Therefore, this study carries out a mechanical and biological characterization of mineral-hydrogel scaffolds in order to find the best compositions. Different proportions of calcium compounds (CaCO₃ and CaHPO₄) are used to make up between 20% and 30% of the minerals used in a mineral-hydrogel mix. This addition of minerals enhances not only the mechanical properties, but also the biological ones. On the one hand, the higher the amount of minerals added to the composition, the better the mechanical properties obtained. Additionally, as the proportion of CaCO₃ in comparison with CaHPO₄ rises, the mechanical properties improve. On the other hand, both cell proliferation and mineralization are improved with the addition of calcium minerals.

Silk-based microcarriers: current developments and future perspectives

Cell-seeded microcarriers (MCs) are currently one of the most promising topics in biotechnology. These systems are supportive structures for cell growth and expansion that allow efficient nutrient and gas transfer between the media and the attached cells. Silk proteins have been increasingly used for this purpose in the past few years due to their biocompatibility, biodegradability and non-toxicity. To date, several silk fibroin spherical MCs in combination with alginate, gelatin and calcium phosphates have been reported with very interesting outcomes. In addition, other silk-based three-dimensional structures such as microparticles with chitosan and collagen, as well as organoids, have been increasingly studied. In this study, the physicochemical and biological properties of these biomaterials, as well as the recent methodologies for their processing and for cell culture, are discussed. The potential biomedical applications are also addressed. In addition, an analysis of the future perspectives is presented, where the potential of innovative silk-based MCs processing technologies is highlighted.

Automatic detection of calcium phosphate deposit plugs at the terminal ends of kidney tubules

Kidney stones are a common urologic condition with a high amount of recurrence. Recurrence depends on a multitude of factors the incidence of precursors to kidney stones, plugs, and plaques. One method of characterising the stone precursors is endoscopic assessment, though it is manual and time-consuming. Deep learning has become a popular technique for semantic segmentation because of the high accuracy that has been demonstrated. The present Letter examined the efficacy of deep learning to segment the renal papilla, plaque, and plugs. A U-Net model with ResNet-34 encoder was tested; the Letter examined dropout (to avoid overtraining) and two different loss functions (to address the class imbalance problem. The models were then trained in 1666 images and tested on 185 images. The Jaccard-cross-entropy loss function was more effective than the focal loss function. The model with the dropout rate 0.4 was found to be more effective due to its generalisability. The model was largely successful at delineating the papilla. The model was able to correctly detect the plaques and plugs; however, small plaques were challenging. Deep learning was found to be applicable for segmentation of an endoscopic image for the papilla, plaque, and plug, with room for improvement.

Evaluation of antibacterial property of hydroxyapatite and zirconium oxide-modificated magnetic nanoparticles against Staphylococcus aureus and Escherichia coli

In the first section of this research, superparamagnetic nanoparticles (NPs) (Fe3O4) modified with hydroxyapatite (HAP) and zirconium oxide (ZrO2) and thereby Fe3O4/HAP and Fe3O4/ZrO2 NPs were synthesised through co-precipitation method. Then Fe3O4/HAP and Fe3O4/ZrO2 NPs characterised with various techniques such as X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Brunauer-Emmett-Teller, Fourier transform infrared, and vibrating sample magnetometer. Observed results confirmed the successful synthesis of desired NPs. In the second section, the antibacterial activity of synthesised magnetic NPs (MNPs) was investigated. This investigation performed with multiple microbial cultivations on the two bacteria; Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Obtained results proved that although both MNPs have good antibacterial properties, however, Fe3O4/HAP NP has greater antibacterial performance than the other. Based on minimum inhibitory concentration and minimum bactericidal concentration evaluations, S. aureus bacteria are more sensitive to both NPs. These nanocomposites combine the advantages of MNP and antibacterial effects, with distinctive merits including easy preparation, high inactivation capacity, and easy isolation from sample solutions by the application of an external magnetic field.

Aqueous extract of broccoli mediated synthesis of CaO nanoparticles and its application in the photocatalytic degradation of bromocrescol green

CaO nanoparticles have been prepared using CaCl₂ and aqueous extract of broccoli as a precursor and reducing agent, respectively. Different volumes of the aqueous broccoli extract were utilised to obtain Ca(OH)₂ and subsequent calcination gave CaO nanoparticles. The synthesised CaO was confirmed by powder X-ray diffraction (XRD). The morphology was studied using transmittance electron microscopy (TEM), and the surface composition of Ca(OH)₂ was explored using Fourier transform infrared spectroscopy. The major functional groups present in the capping material responsible for the reduction of the metal salt and the surface passivation of Ca(OH)₂ were identified. The XRD pattern revealed cubic phase for all the CaO nanoparticles, and the crystallite size was estimated using Scherrer's equation showed a variation which is dependent on the volume of the extract used. TEM analysis showed different shapes, while the selected area electron diffraction (SAED) results confirmed the crystallinity of the nanoparticles. Thermogravimetric analysis of Ca(OH)₂ showed the decomposition product to be CaO. Sample C3, which has the smallest particle size, was used as a catalyst for the degradation of bromocresol green via photo irradiation with ultraviolet light and the result revealed a degradation efficiency of 60.1%.

Development and characterisation of novel Ce‐doped hydroxyapatite–Fe3 O4 nanocomposites and their in vitro biological evaluations for biomedical applications

Hydroxyapatite (HAP: Ca₁₀ (PO₄)₆ (OH)₂) is extensively used in biomedical field because of its biocompatibility, osteoconductivity and non‐toxicity properties. However, HAP exhibits poor mechanical strength and bacterial restriction behavior. To overcome these drawbacks, various metal ions such as Ag⁺, Zn²⁺, Cu²⁺, Ti⁴⁺ and Ce^4+/3+ are incorporated in HAP matrix to increase the mechanical and biological properties. Among these, Cerium (Ce) is selected as antibacterial agent due to its high thermal stability and its applications in dental fillings, bone healing and catheters. Fe₃ O₄ nanoparticles were used in hyperthermia treatment, magnetic fluid recordings and catalysis. In this present study, we have synthesized nanocomposites consisting of 1.25% Ce doped HAP with various concentrations of Fe₃ O₄ NPs as 90:10 (C‐1), 70:30 (C‐2) and 50:50 wt% (C‐3) using ball milling technique. The obtained Ce@HAP‐Fe₃ O₄ nanocomposites were characterized by ATR‐FTIR, XRD, VSM, SEM‐EDAX and TEM analysis. Further, the fabricated Ce@HAP‐Fe₃ O₄ nanocomposites were tested for its antibacterial activity towards Staphylococcus aureus (S. aureus) and Escherichia coli (E.coli), where C‐3 composites exhibit the excellent pathogen inhibition towards E.coli. In addition, the cytotoxicity evaluation on C‐3 nanocomposites by in vitro biocompatibility study using MG‐63 cells shows the prominent viable cell enhancement up to 400µg/mL concentrations.

Nanofibrillated Cellulose Templated Membranes with High Permeance

One of the most challenging aspects of using nanofibrillated cellulose (NFC) for membranes production is their limited permeance. When NFC membranes are produced from aqueous suspensions, depending on their grammage, the permeances are in the range of a few decades of L/(hm²MPa) not matching satisfactory filtration times. We present a fast and sustainable solution to increase the permeances of such membranes through a combination of solvent exchange of the NFC suspension with ethanol and the use of a removable template, a mixture of calcium compounds (CC). The effect of the CC/NFC ratio was screened for various concentrations. The permeance of water could be increased by as much as 2-3 times as compared to nontemplated membranes. Further, the membranes showed the ability for penetration of water-soluble macromolecules, contaminant rejection of suspended solid particles, and thus fluids (such as orange juice) could be concentrated, with a view to applications in food industry.