Hard Substance Research Articles

The human fluorescence discrimination as precondition for the use of fluorescence-aided identification techniques (FIT)

ObjectivesThe fluorescence-aided identification technique (FIT) is based on the fluorescence properties of dental materials, specifically the intensity of their fluorescence compared to the autofluorescence of hard dental substances; this creates a perceived contrast between dental material and tooth. However, no studies to date have determined the extent to which the fluorescence intensity of tooth-colored dental materials must differ from that of natural autofluorescence to ensure reliable visual detection. The aim of this study was therefore to determine, for the first time, how pronounced the difference between fluorescence intensity and autofluorescence must be to reliably identify tooth-colored material. MethodsTen dentists assessed six different resin-based composite (RBC) samples of varying fluorescence intensity placed in the cavities of ten extracted teeth under standardized fluorescence-exciting illumination. The outcome variable was fluorescence perceptibility. Their assessments of the outcome variable were compared with measurements of the fluorescence intensities of the RBCs and the surrounding dental hard tissues, which were expressed as a fluorescence intensity ratio. Demographic data of the participants, including age, gender, and professional experience, were also recorded. ResultsNo significant differences were found for visual fluorescence perceptibility in relation to the explanatory variables of gender (p = 0.14), age (p = 0.13), and professional experience (p = 0.34). In contrast, the fluorescence intensity ratio was significantly different (p < 0.0001). SignificanceFor both clinicians and manufacturers, fluorescence intensity levels are important when selecting or developing FIT-compatible materials. Our results suggest that the fluorescence intensity levels of dental materials should be no more than 75% and no less than 200% of tooth natural autofluorescence to ensure reliable detection of tooth-colored materials.

Establishment of a Protocol for Viability qPCR in Dental Hard Tissues.

The aim of the study was to establish a live/dead qPCR with propidium monoazide (PMA) that can quantitatively differentiate between viable/non-viable microorganisms in dental hard tissues. Human premolars (n = 88) were prepared with nickel-titanium instruments and incubated with E. faecalis (21 d). Subsequently, the bacteria in half of the teeth were devitalized by heat inactivation (100 °C, 2 h). The following parameters were tested: PMA concentrations at 0 µmol (control), 50 µmol, 100 µmol, and 200 µmol; PMA incubation times of 30 min and 60 min, and blue light treatment for 30 min and 60 min. The teeth were ground using a cryomill and the bacterial DNA was quantified using qPCR, ANOVA, and p = 0.05. The qPCR of the control group detected a similar number of avital 9.94 × 106 and vital 1.61 × 107 bacterial cells. The use of PMA inhibited the amplification of DNA from non-viable cells during qPCR. As a result, the best detection of avital bacteria was achieved with the following PMA parameters: (concentration, incubation time, blue light treatment) 200-30-30; 5.53 × 104 (avital) and 1.21 × 100.7 (vital). The live/dead qPCR method using PMA treatment is suitable for the differentiation and quantification of viable/non-viable microorganisms in dentin, as well as to evaluate the effectiveness of different preparation procedures and antimicrobial irrigants in other biological hard substances.

Development of the wastewater treatment technology for the mine ‘Ternivska’ of the Kryvyi Rih iron ore plant

ABSTRACT Wastewater treatment in mining and mineral processing technology is a topical problem worldwide. The purpose of this study is to substantiate and develop the technology of complex wastewater treatment for the mine ‘Ternivska’ of the Public Joint Stock Company ‘Kryvyi Rih Iron Ore Plant’ with the production of highly purified water suitable for secondary use or ecologically safe discharge into surface water bodies. The proposed technology is based on the sequential application of the following stages: preliminary treatment of contaminated mine waters by coagulation and soda-lime softening methods to remove hardness, suspended solids, and colloidal substances; desalination via reverse osmosis; evaporation and crystallization of reverse osmosis concentrate in a vacuum evaporation unit; dehydration of salt sludge in a centrifuge with drying of salt crystals in a dryer. The treatment of mine water with an initial salinity of 80 g/L will give an annual effect of 1357 thousand m3 of desalinated water with a mineralization of up to 100 mg/L and 739.6 tons of mineral salt mixture. The purified water can serve as an additional source of fresh water for technological needs in industry or alternative purposes. The obtained solid salt product can be used as an alternative reagent for water-softening processes. In general, the proposed processing of mineralized mine water can be considered a zero-waste technology with clean water production and by-product utilization.

Foot, Toe, and Nail Changes: Are They Interdependent?

Plain Language SummaryThe foot of man is a strong organ consisting of 26 bones, 33 joints, of which 20 are actively movable, and more than 100 muscles, tendons and connective tissue bands keeping this complex body part together. The foot is usually divided into three parts, the hind, mid, and forefoot. The latter contains the toes as their most forward-pointing parts. They are covered by the nails, which are plates of hard horn substance. The toes increase the weight-bearing surface of the foot and are thus important for balance while standing and walking, for running and jumping. If the foot is not healthy this will seriously influence its function and also change the toenails. An examination of more than 1,600 persons’ toenail photographs was performed to find out, whether foot anomalies can be found in patients with toenail changes. This was in fact the case in a very high number of the patients.

Teeth can Tell a Story About Childhood!

Tooth enamel is the hardest substance in the human body. It begins forming during pregnancy and the way it forms can provide valuable information about early life. The cells that produce enamel are extremely sensitive to disturbances, so when a child experiences some kinds of stress during enamel development (childhood diseases, fever, or low concentration of oxygen in the blood for example), layers of enamel may contain “scars” reflecting the stressful experience. The type of enamel scars can tell dentists a story about what may have happened before the person was born or shortly after birth. Understanding enamel development is important for knowing the difference between normal enamel and abnormal changes, and such knowledge can help dentists to diagnose and treat enamel issues, to keep the teeth healthy.

Denticles: dental pulp calculi

Denticles (pulp stones) are round to oval hard substance formations of various sizes that occur in the dental pulp or in the area of the pulpal dentin wall. They can occur free, without connection to the pulp wall (free denticles), fused to the pulp wall (adherent denticles) or embedded in the pulp wall (interstitial denticles).

In Vitro Comparative of the Cutting Efficiency and Smear Layer of Ceramic Burs, Conventional Tungsten Carbide Burs and Diamond Stone

Purpose: To compare the cutting efficiency and the smear layer of three different types of burs ceramic, tungsten carbide and diamond stone. Materials and Methods:135 mica-based glass ceramics (Vita blocs Mark II) blocks were used to valuate cutting efficiency by weight loss method. Five points from each type of burs: Cera Bur (komet, Brasseler, Germany): K59, Tungsten Carbide tapered Bur (komet, Brasseler, Germany): H2 010 and diamond points (komet, Brasseler, Germany): 957AM 314 010, were used for cutting procedures. Each bur had made 30 seconds duration cut, each bur was used three times. Cutting was performed under standardized protocol using a specially designed machine for this purpose. Twelve unerupted human third molars were used to obtain Dentin slabs. Cutting was performed using the same protocol and the smear layer created was observed by means of scanning electron microscope. Results: The values of weight loss were: 0.18 ± 0.08 gm, 0.40 ± 0.07 and 0.50 ± 0.07 gm for each bur respectively. Less dense smear layer was observed with the Cera Bur when compared to the tungsten carbide and diamond burs. Conclusion: The new tapered fissure ceramic bur can be considered a promising tool for minimally dentistry, while providing a minimal reduction of the sound, hard tooth substance.

Physical and Mechanical Properties of CrN/AlN Coating Obtained by Vacuum-Arc Deposition with Alternative Separation of Hard Substance Flows

Physical and Mechanical Properties of CrN/AlN Coating Obtained by Vacuum-Arc Deposition with Alternative Separation of Hard Substance Flows

Research and development of demineralised dentin-derived collagen granule bone regeneration materials using animal teeth

The enamel that forms the outer layer of a tooth is the hardest substance in the human body and the structure of the teeth present an opportunity for investigation. For example, Dr Naoto Okubo, who has expertise in dentistry, is interested in the raw material from which the teeth are composed ‐ dentin. Dentin has a special structure known as â–˜ivory tubulesâ–™ that only exists in teeth and can be said to be a communicating porous structure. There is potential that it could be used in the development of new implantable biomaterials. Okuboâ–™s current research is exploring whether dentin can be used as a material for building bioregenerative scaffolds. He is based in the Faculty of Pharmaceutical sciences, Department of Molecular and Cellular Medicine, Hokkaido University, Japan, and is Project Leader of the Bovine Demineralized Dentin Matrix (B-DDM) projects. One of the reasons that dentin is suitable as a material for bioregenerative scaffolds is because the most important quality for bioregenerative scaffolds is that they do not interfere with the blood supply when they have been implanted. In addition, it has the strength needed to be used for bioregenerative scaffolds. In their work to use dentin and its tubule structure for the development of bioregenerative scaffolds Okubo and the team are using dentin in such a way that enables them to remove some or all the inorganic components at the same time as maintaining the tissue structure. This means the foundation of the scaffold is mainly composed of type 1 collagen, which has excellent blood permeability and high natural strength.

Non-invasive and Locally Invasive Hypercellular Peripheral Odontogenic Fibroma in 20 Dogs.

Medical records of dogs with an initial histopathological diagnosis of odontogenic sarcoma were reviewed for information on signalment, body weight, medical history, clinical signs, physical examination and diagnostic imaging findings, surgical procedure performed, and histologic characteristics. Twenty dogs were deemed to fit the criteria following the rigorous histology review process. These tumors were characterized by hypercellularity of the spindle cell component with less intervening stroma, mitotic activity, and variable presence of odontogenic epithelium and hard substance (cementum/dentin/bone). Non-invasive or locally invasive hypercellular peripheral odontogenic fibroma is suggested by the authors to describe these tumors. There were no signs of recurrence of any of the masses following surgical excisions with varying margins.

Direct adhesive reconstructions for restoration of posterior teeth with erosive tooth wear

The restorative treatment of dental hard tissue loss, e.g., due to erosion, and the rehabilitation of the original vertical bite dimension confronts the dentist with problems when implementing the therapy. Traditionally, this therapy is conducted with laboratory-fabricated workpieces made of ceramics which usually require a preparation of the remaining tooth substance and also causes high costs for the patient. Therefore, alternative methods should be considered. This article presents the use of direct adhesive composite restorations as a way of reconstructing a dentition severely altered by erosion. To reconstruct the occlusal surfaces, transfer splints are used that are made on the basis of individual wax-up models. The procedure described is a well-researched and proven method for restoring teeth with erosion-related loss of hard tooth substance. As with all new procedures, there will be a certain learning curve for the practical dentist after which high-quality restorations can be implemented with this technique.

The erosive effect of various drinks, foods, stimulants, medications and mouthwashes on human tooth enamel

Two forms of non-carious dental disorder - erosive tooth hard tissue loss and dental erosion - have been increasingly observed in recent years. Dental erosion is the chemical loss of dental hard substances caused by exposure to acids not derived from oral bacteria. Mechanical forces from, for example, the tongue, the cheeks or toothbrushing, increase loss of partly-demineralized tooth surfaces and the cumulative loss of dental hard tissue is defined as erosive tooth wear (ETW). Dental hard tissue losses which occur because of very frequent acid exposure, such as through increased vomiting, but without mechanical stress, are also assigned to tooth erosion. Without prior softening, practically no loss of enamel takes place due to abrasion with the modern Western diet. The present work is a continuation of earlier work. A total of 226 beverages, food, stimulants as well as medicines and mouthwashes were tested for their erosive potential on premolars and deciduous molars covered with a human pellicle. The influence of temperature, phosphate and calcium was also investigated in additional experiments. The change in hardness before and after immersion in the respective test substance was measured and the erosive potential was classified. For each test product, we determined pH and other properties which were possibly related to erosive potential. There were considerable and sometimes surprising differences between the tested products. The addition of phosphate did not influence the erosive potential of the liquids, but calcium did. A modified erosion scheme is presented, which incorporates these and other new findings.&#x0D; Accepted for publication: February 6, 2023&#x0D; Published online: February 21, 2023

The erosive effect of various drinks, foods, stimulants, medications and mouthwashes on human tooth enamel.

Two forms of non-carious dental disorder - erosive tooth hard tissue loss and dental erosion - have been increasingly observed in recent years. Dental erosion is the chemical loss of dental hard substances caused by exposure to acids not derived from oral bacteria. Mechanical forces from, for example, the tongue, the cheeks or toothbrushing, increase loss of partly-demineralized tooth surfaces and the cumulative loss of dental hard tissue is defined as erosive tooth wear (ETW). Dental hard tissue losses which occur because of very frequent acid exposure, such as through increased vomiting, but without mechanical stress, are also assigned to tooth erosion. Without prior softening, practically no loss of enamel takes place due to abrasion with the modern Western diet. The present work is a continuation of earlier work. A total of 226 beverages, food, stimulants as well as medicines and mouthwashes were tested for their erosive potential on premolars and deciduous molars covered with a human pellicle. The influence of temperature, phosphate and calcium was also investigated in additional experiments. The change in hardness before and after immersion in the respective test substance was measured and the erosive potential was classified. For each test product, we determined pH and other properties which were possibly related to erosive potential. There were considerable and sometimes surprising differences between the tested products. The addition of phosphate did not influence the erosive potential of the liquids, but calcium did. A modified erosion scheme is presented, which incorporates these and other new findings.

Shaking Things from the Ground-Up: A Systematic Overview of the Mechanochemistry of Hard and High-Melting Inorganic Materials.

We provide a systematic overview of the mechanochemical reactions of inorganic solids, notably simple binary compounds, such as oxides, nitrides, carbides, sulphides, phosphides, hydrides, borides, borane derivatives, and related systems. Whereas the solid state has been traditionally considered to be of little synthetic value by the broader community of synthetic chemists, the solid-state community, and in particular researchers focusing on the reactions of inorganic materials, have thrived in building a rich and dynamic research field based on mechanically-driven transformations of inorganic substances typically seen as inert and high-melting. This review provides an insight into the chemical richness of such mechanochemical reactions and, at the same time, offers their tentative categorisation based on transformation type, resulting in seven distinct groupings: (i) the formation of adducts, (ii) the reactions of dehydration; (iii) oxidation-reduction (redox) reactions; (iv) metathesis (or exchange) reactions; (v) doping and structural rearrangements, including reactions involving the reaction vessel (the milling jar); (vi) acid-base reactions, and (vii) other, mixed type reactions. At the same time, we offer a parallel description of inorganic mechanochemical reactions depending on the reaction conditions, as those that: (i) take place under mild conditions (e.g., manual grinding using a mortar and a pestle); (ii) proceed gradually under mechanical milling; (iii) are self-sustained and initiated by mechanical milling, i.e., mechanically induced self-propagating reactions (MSRs); and (iv) proceed only via harsh grinding and are a result of chemical reactivity under strongly non-equilibrium conditions. By elaborating on typical examples and general principles in the mechanochemistry of hard and high-melting substances, this review provides a suitable complement to the existing literature, focusing on the properties and mechanochemical reactions of inorganic solids, such as nanomaterials and catalysts.

Experimental Investigation of Microstructure and Phase Characterization of Rice Hush Ash (RHA) for Potential Utilization in Metal Matrix Composites

Recent trends in material research and development of composite materials are geared towards reducing cost, recycling and ensuring environmental sustainability. Agricultural waste derivatives have proven to be an alternative or complimentary reinforcement material in the development of metal matrix composites. The current work is an investigation of the microstructure and phase characterization of rice husk ash (RHA) obtained through open air burning. Scanning electron microscopy (SEM) equipped with electron dispersive spectrometry (EDS) was used for the microstructural examination, X –ray fluorescence (XRF) forthe mineralogical composition and X –ray diffraction (XRD) for the determination of phases present. Results revealed that RHA is highly siliceous with 93.8% SiO2, highly porous and fibrous material with a wide surface area. EDS profile confirmed the presence of SiO2and Al2O3. The XRD pattern revealed the presence of quartz, crystabalite and anorthite phases in the RHA. Silica is a hard substance with strong covalent bonds similar to diamond with hardness rating of 7 on Mohs scale and melting point of 1713OC. Thus,RHA can be suitable used as a reinforcing material in the development of metal matrix composites for automotive components

Effect of Almond Milk on Tooth Enamel Surface Hardness

Introduction: Enamel is the hardest substance in the human body and serves as the wear-resistant outer layer of the dental crown. Demineralization releases mineral ions which cause a decrease in the enamel surface hardness. Demineralization could be neutralized to recover minerals, and this process is called remineralization. Almond milk was an alternative to cow’s milk, supporting tooth enamel surface remineralization. Purpose: To determine the effect of almond milk on enamel hardness. Methods: Twenty maxillary premolars were divided into group A (control) and group B (almond milk). Before treatment, samples were soaked in 1% citric acid. Enamel hardness was tested with Vickers Hardness Tester. The statistical tests used in this study were Paired t-test and Independent Sample t-Test. Results: The results of the paired sample test got significant results in groups A and B in the comparison of pretest - 1% citric acid, and 1% citric acid - posttest, which means that there was a significant difference in enamel hardness values. However, the results obtained were not substantial in groups A and B in the posttest- pretest comparison. There was no significant difference between Group A and Group B in the independent sample test results. There was an increase before and after, but it was not much different when compared to the control. Conclusion: Almond milk can increase enamel surface hardness but cannot reverse the initial enamel surface hardness value.

Potential Methods for Limiting the Consumption of Machine Components Exposed to Abrasive Wear

The analysis of the behavior in exploitation of the extraction, transportation and utilization of hard rock type mineral substances proved that one of the most extended and aggressive forms of wear is abrasive wear. The effects of abrasive wear on the machine components and their economic implications are significant, especially due to the operational pauses coming up in the technological flows that serve specific activities. This study presents two ways of limiting the consumption of tamping tools for the railway machines that are submitted to abrasive wear, namely, by reconditioning with the help of electrodes for overlaying welding with alloys of preestablished characteristics; by executing cast cleats from composite material in which metal carbides were infiltrated by diffusion. The great number of cast cleats tested in exploitation allowed a reliability and maintainability analysis to be made using the Weibull++ program, including the determination of the necessary number of cleats for 5000 h of functioning. The results of the experiments performed to this end demonstrated that both the reconditioning and execution of spare parts, with the help of reusable materials, could be solutions for sustainability in several economic fields, especially in those where the production costs are high.

Influence of plant protein‐dietary fiber composite gel and Lactiplantibacillus plantarum XC‐3 on quality characteristics of Chinese dry fermented sausage

To explore the reuse of brewer's grains and develop novel Chinese fermented sausage with healthy characteristics, the influences of the addition of plant protein-dietary fiber composite gel and Lactiplantibacillus plantarum XC-3 on Chinese dry fermented sausages were studied. The results showed that the addition of Lactiplantibacillus plantarum XC-3 reduced the pH, water activity, total volatile base nitrogen, residual nitrite, and thiobarbituric acid of fermented sausages while increasing the hardness, springiness, chewiness, and total volatile flavor substances of the fermented sausages (p < 0.05). In all, 69 volatile flavor substances were identified in the fermented sausages. The addition of plant protein-dietary fiber composite gel resulted in a significant increase in the acids and esters content of fermented sausages (p < 0.05), but the increase in gel addition resulted in a decrease in the total content of volatile flavor substances in fermented sausages (p < 0.05) (still much higher than in the fermented sausage without gel addition). Novelty impact statement The addition of plant protein-dietary fiber gel and inoculation with Lactiplantibacillus plantarum XC-3 effectively reduced harmful carcinogens in fermented sausages while promoting the production of flavor substances and adding some new ones. The novel fermented sausage developed in this study is delicious and healthy, which provides theoretical support for the development of healthy foods in the meat processing industry.

Correlation of ECG Values to the Behavior of Heart Attack Sufferers

Abstract: Heart attack is among one of the deadliest of cardiovascular diseases. It happens as circulation or blood flow to heart muscle is interrupted, causing the heart muscle to damage or die. The essential reason for most heart assaults could be a blockage which causes blood stream to one of the coronary courses, imperative channels through which blood voyages to the heart muscle, to become reduced or obstructed. When blood stream is discouraged or decreased, the heart muscle is quickly denied of ruddy blood cells which carry the fundamental oxygen basic for supporting life and awareness in the human body. It takes as few as six to eight minutes without oxygen to cause the heart muscle to capture, driving to the individual’s passing. And the cause of most heart attacks is plaque, a hard substance which builds up over time in the coronary arteries. Plaque, a substance made up of numerous cells and cholesterol (fat), draws platelets, etc., which increase over time, causing a blockage large enough to diminish or block blood flow to heart muscle. Cardiac disease medications are regularly being subjected to the securing and investigation of tremendous amount of advanced cardiac information. The objective of the project is to make the analysis on the digital ECG dataset is made on the various medical terminologies that correlates towards Heart Attack. To implement a Deep Learning Model that correlates what digital ECG values maps to the abnormal patterns which leads to Heart Attack. To analysis further on gender, age group and lifestyle of a Heart Attack Patients.

Oral rehabilitation of a patient using a digital protocol

To explore the possibilities of oral rehabilitation in fixed prosthetics using a digital protocol. A 55-year-old patient came to our clinic because of functional and aesthetic problems in the oral cavity, which were mainly related to the wear of the hard dental substance and the consequent reduction of the vertical dimension of the occlusion. In rehabilitation, we use a digital single-lens reflexe (DSLR) Canon EOS 5D Mark IV (Ota City, Tokyo, Japan) and an intraoral scanner (IOS) 3 Shape -Trios (Copenhagen, Denmark). We used a DSLR camera to take preoperative photographs of the patient, which were sent to the dental laboratory via We Transfer program, while scans of the upper and lower jaws, as well as a bite scan, were also sent to the laboratory via the Internet connection in 3 Shape Dental Desktop (v.1.7.3). In the digital dental laboratory, the entire work from planning to cementation was fully digitally created in the 3 Shape Dental Designer program (v. 19.0.3). We completely restored the function and aesthetics of the orofacial system of the patient in a faster, more predictable, and precise way than we could have done by using conventional techniques. In dentistry today, there are still no standardized protocols for oral rehabilitation of patients completely using digital technology. Therefore, we would like to show one possibility of oral rehabilitation in fixed prosthetics with a digital workflow.