Demineralization Process Research Articles

The increased sensitivity of dentin: the mechanisms of remineralization using toothpaste with tin fluoride

The purpose of the study was clinical and laboratory analysis of the remineralizing properties and clinical efficacy of the course application of the Sensodyne Rapid Relief therapeutic and prophylactic toothpaste for sensitive teeth with tin fluoride. The study involved 50 overwise healthy patients aged from 18 to 25 years diagnosed with a localized form of hyperesthesia of hard dental tissues and no signs of acute inflammation of periodontal tissues. After 7 days of clinical observation and daily use of the toothpaste the hygienic condition of the oral cavity in all patients improved: oral hygiene index was 1.02±0.2 units; gum inflammation index (PMA) - 8.0±1.5%; the absence of hyperesthesia was diagnosed (1 point, p≤0.05). Examination of patients after 14 and 28 days confirmed the absence of pain in 100%, the organoleptic properties of the toothpaste under investigation were also highly appreciated by the participants. A laboratory study showed that patients have an increase in the pH value of mixed saliva and a decrease in its buffer capacity by 13.4±2.25%, which contributes to a more effective remineralizing effect of calcium ions by calcium-binding proteins of mixed saliva. The concentration of fluoride ions in the saliva of patients of both groups increased by average rate of 34±0.5% per week. The combination of tin and fluoride is more effective than fluoride alone. The presence of tin ions causes a higher ability of fluorides to bind with calcium ions on the surface of the dentin and dentinal tubules, inhibits the process of demineralization, enhances the additive interaction of the ions forming the acid-resistant layer on the surface of the dentin and dentinal tubules, leading to a decrease in hyperesthesia of the teeth.

Remineralizing Potential of Nano-Silver-Fluoride for Tooth Enamel: An Optical Coherence Tomography Analysis

Objective: To evaluate the use of nanosilver fluoride in the enamel remineralization process through optical coherence tomography. Material and Methods: All samples were submitted to demineralization process by pH cycling during 14 days and randomly distributed into three groups (n = 11): Nanosilver Fluoride (NSF), Sodium fluoride (NaF), and negative control. Optical coherence tomography images were acquired at three different moments: initial stage (T0), post caries formation (T1), and post pH cycling (T2). The integrity of the enamel surface and the measurement of the volume loss for the tissue after pH cycling in comparison to initial images were obtained from optical coherence tomography images. Results: After analyzing the exponential decay of A-scans from each group, it was possible to identify differences in light propagation among samples. In T1 it is not possible to visualize the dentin-enamel junction, probably due to the higher back scattering of the demineralized enamel, which does not allow light to reach the dentin. The decay curves obtained from NaF and nanosilver fluoride groups showed similar behavior, while the negative group showed lower extinction coefficient. Conclusion: Nanosilver fluoride showed the best effect against caries compared to conventional fluoride treatments.

Remineralization potential of dentifrice containing nanohydroxyapatite on artificial carious lesions of enamel: A comparative in vitro study

A carious lesion is the accumulation of numerous episodes of demineralization and remineralization, rather than a unidirectional demineralization process. Tooth destruction can be arrested or reversed by the frequent delivery of fluoride or calcium/phosphorous ions to the tooth surface. Nanohydroxyapatite particle-containing dentifrices are the newer generation of products which claim to remineralize enamel lesions effectively. The aim of this study was to evaluate and compare the remineralization ability of dentifrices containing nanohydroxyapatite, NovaMin, and amine fluoride on artificial enamel caries. In this in vitro study, extracted sound premolars were placed in a demineralizing solution to produce deep artificial carious lesions. The teeth were then sectioned longitudinally and divided into three groups (n = 16 in each group): Group A (nanohydroxyapatite), Group B (NovaMin), and Group C (fluoride). The sections were then subjected to pH cycling for 7 days. Polarized light microscopy was utilized to record the depth of the lesions before and after treatment with the selected dentifrices. Changes in the mean lesion depth were statistically analyzed by one-way ANOVA and t-test. The level of significance was assessed at P < 0.05. The lesion depth decreased significantly by 10.56% in Group A, 6.73% in Group B, and 9.58% in Group C (paired t-test, P < 0.001). When comparisons were made across the groups, no statistical significance was found between the Groups A, B, and C (ANOVA test, P > 0.05). All three dentifrices were found to be effective in remineralizing artificial carious lesions. Nanohydroxyapatite dentifrice produced significantly better results compared to fluoride- and NovaMin-containing dentifrices, instigating for its use in the management of early carious lesions.

Assessment of the Raman spectroscopy effectiveness in determining the early changes in human enamel caused by artificial caries.

Current diagnostic methods for enamel caries detection are unable to detect caries lesions at a very early stage. Previous studies indicated that Raman spectroscopy is a promising and effective tool for the detection of early caries. In our previous work, we showed that several independent parameters obtained during the analysis of the Raman spectra of enamel allow for the identification of carious lesions formed in the oral cavity (natural caries). The aim of this research was to estimate the effectiveness of Raman spectroscopy in the determination of specific changes in human enamel affected by artificial caries. The values of parameters obtained in a previous study were compared with those obtained in this work. Moreover, the direction of parameter value changes during caries formation was checked, and also compared with earlier results. The results show that Raman maps permit the determination of local variations in the enamel structure affected by the early demineralization process. As follows from these and previous results a few parameters such as depolarization ratio, polarization anisotropy, position, intensity and full width at half maximum of the Raman band allow for the identification of the enamel caries changes. This investigation contributes to the development of Raman spectroscopy for the identification of caries at a stage before visual changes in enamel.

Effect of demineralization process with voltage application on mechanical properties of bovine cortical bone

Effect of demineralization process with voltage application on mechanical properties of bovine cortical bone

Voltage spike and electroconvective vortices generation during electrodialysis under pulsed electric field: Impact on demineralization process efficiency and energy consumption

Abstract Electrodialysis (ED) with pulsed electric field (PEF) has never been tested on complex food system such as sweet whey. In this study, seven PEF pulse-pause combinations were compared with DC current to assess their impacts on whey demineralization. High-frequency PEF improved the demineralization rate by 81% while reducing the energy consumption by about 16%. This was explained by the emergence of electroconvective vortices (ECV) at the beginning of each pulse due to the appearance of a voltage spike. Since their lifetime are around 0.5 s, these ECV did not have time to fade off during the whole process in the case of high-frequency PEFs increasing consequently the mass transfer. Furthermore, PEF ratio of 1 decreased pH changes and thus could prevent scaling and organic fouling formation. Hence, ED with PEF is a new advantageous energy-efficient approach for the demineralization of whey that could be used in the dairy industries. Industrial relevance This study highlights the beneficial effects of using pulsed electric field (PEF) during ED in comparison to the DC current condition currently used everywhere in industry. First, for the same demineralization rate of sweet whey, PEF requires 16% less energy. This could allow the industries to better deal with the regulatory issues arising from the sustainable development goals. In addition, the use of PEF also prevents the fouling and scaling formation on the membrane, and thus could decrease the load of cleaning agent and the cleaning time required per amount of processed whey. High-frequency PEF such as 0.1 s-0.1 s is a promising greener alternative to conventional ED for demineralization of the million tons of whey generated by the cheese industry every year.

COMPARISON OF SALIVARY pH BEFORE AND AFTER CONSUMING A SOLUTION OF SUGAR AND PALM SUGAR IN DENTISTRY FACULTY’S STUDENT OF ANDALAS UNIVERSITY

Sugar ( sucrose ) is a carbohydrate compound which is soluble in water and directly absorbed by the body to convert into energy . Diet sugar ( sucrose ) can affect the pH of saliva , where the compounds have fermented in the mouth which produces acid to lower the pH of saliva and the results of this activity will initiate the process of demineralization of tooth structure. The palm sugar contains sucrose higher at 84 % compared with 20 % of sugar cane.8 The purpose of this study was to determine differences in comparison the pH of saliva before and after consuming a solution of sugar and palm sugar. This study was an experimental study using pre-test and post-test design. The samples used as many as 26 people. Each sample was given treatment consumes sugar and palm sugar solution. Salivary pH measurements using dental saliva pH indicator. Analysis of data using the Wilcoxon test. The result show an average difference in the pH of saliva after consuming a solution of sugar of 0.57 ± 0.32 while the average difference in the pH of saliva after consuming palm sugar solution at 0.67 ± 0.40. The value of p&gt; 0.05 so there is no significant difference. Based on the research that has been done, it can be concluded that consuming a solution of sugar and palm sugar solutions together can decrease the pH of saliva. &#x0D; Keywords : salivary pH , sugar solution , palm sugar solution

Chemometric analysis of the Raman spectra for determination of the composition of bones with different porosity

The results of application of the Raman spectroscopy method for evaluation of porosity influence on the process of bone fabric demineralization and for evaluation of component composition of bone grafts with different porosity in the process of their treatment are presented. The comparison has shown the difference in intensities of spectral lines of the mineralized samples on the wavenumbers 960 cm−1 and 1070 cm−1, corresponding to hydroxyapatite phosphate ion and carbonate ion, as well as of the demineralized samples on the wavenumbers 1000 cm−1 (phenylalanine aromatic ring) and 1167 cm−1 (GAG). The coefficients were implied and the two-dimensional analysis, showing the pore size influence on the demineralization process. This is due to the fact that the demineralization process doesn’t include acid mixing, so the areas of its non-uniform concentration appear in its interaction with the samples, particularly in the small-pored areas

Chemometric analysis of the Raman spectra for determination of the composition of bones with different porosity

The results of application of the Raman spectroscopy method for evaluation of porosity influence on the process of bone fabric demineralization and for evaluation of component composition of bone grafts with different porosity in the process of their treatment are presented. The comparison has shown the difference in intensities of spectral lines of the mineralized samples on the wavenumbers 960 cm−1 and 1070 cm−1, corresponding to hydroxyapatite phosphate ion and carbonate ion, as well as of the demineralized samples on the wavenumbers 1000 cm−1 (phenylalanine aromatic ring) and 1167 cm−1 (GAG). The coefficients were implied and the two-dimensional analysis, showing the pore size influence on the demineralization process. This is due to the fact that the demineralization process doesn’t include acid mixing, so the areas of its non-uniform concentration appear in its interaction with the samples, particularly in the small-pored areas

Antagonism of Bacteria from Dog Dental Plaque against Human Cariogenic Bacteria.

Dental caries are a process of demineralization and destruction of human teeth. They originate through many factors and are associated with biofilm formation, which consists of bacteria adhered to the teeth that form a structurally and functionally organized mass called dental plaque. Both the presence of Streptococcus mutans and the frequent consumption of sucrose correlate with a higher prevalence of caries in humans. In dogs, however, the incidence of this disease is low, due to factors such as differences in dental microbiota and/or their low consumption of sucrose. This work evaluated the antagonism of bacteria from dog's dental plaque against S. mutans, for the identification of producing strains of biotechnological products for use in preventing caries. This study used 95 bacterial isolates of canine dental plaque from the Veterinary Department at the Federal University of Viçosa, Minas Gerais, Brazil. A spot-on-the-lawn method was performed using Brain Heart Infusion agar with catalase for an initial identification of the antagonistic activity. Additional tests were conducted on the isolates classified as antagonists for confirmation of the activity, using modified Mann-Rogosa-Sharpe medium containing low dextrose concentration. These isolates were incubated at 37°C for 24 hours in anaerobiosis. The peptide nature of inhibition was evaluated using the following proteinases: proteinase K from Tritirachium album, bovine pancreatic trypsin, and type XII-A α-amylase from Bacillus licheniformis. In the initial identification of those strains exhibiting antimicrobial activity, 14 were classified as antagonists. One of the isolates (Bacillus sp.) indicated bacteriocinogenic activity, with a deformed inhibition halo on S. mutans by the addition of trypsin. These results suggest that this bacterial isolate may be applicable to biotechnological use to combat the main etiological agent of caries in humans. Further studies are needed to evaluate the bacteriocinogenic nature of the antimicrobial activities of the other 13 antagonistic bacterial isolates.

Pyrolysis behavior of raw/torrefied rice straw after different demineralization processes

This study aims to evaluate the effects of different demineralization processes on the pyrolysis behavior and pyrolysis product properties of raw/torrefied rice straw. To achieve this target, different demineralization pretreatment processes with deionized water, acetic acid and hydrochloric acid solutions of rice straw were carried out, and the detailed information of fuel characteristics, alkali and alkaline earth metals (AAEMs) concentration, thermal degradation behavior and pyrolysis product properties were figured out. The results indicated that demineralization processes improved the fuel characteristics. The removal efficiencies of AAEMs increased in the order hydrochloric acid > acetic acid > deionized water. Torrefied samples exhibited lower removal efficiencies of AAEMs than that of raw samples because of the speciation transformations of AAEMs during torrefaction. More obvious effect of alkali metals on the pyrolysis process can also be obtained than that of alkaline earth metals. Compared with raw rice straw, the effects of demineralization processes on the changes of cellulose crystallinity of torrefied rice straw can be ignored. All the demineralization processes enhanced the bio-oil yield at the expense of biochar and non-condensable gases for raw/torrefied samples. They also have important promoting influence on the properties of bio-oil and biochar by enhancing the sugars formation and improving the fuel characteristics of biochar. The obtained results can be helpful for understanding the pyrolysis behavior of raw/torrefied rice straw after different demineralization processes and for further utilization of biomass resources with high contents of silica and potassium.

EVALUATION OF CARIOGENIC SITUATION IN CHILDREN WITH TYPE 1 DIABETES MELLITUS GIVEN THE MINERALIZING POTENTIAL OF SALIVA AND ENAMEL RESISTANCE

Aim.This study was conducted to evaluate the caries resistance of hard tooh tissues and the state of the calcium and phosphorus metabolism in children with type 1 diabetes mellitus given the mineralizing potential of saliva and antimicrobial protection of the oral cavity.Materials and methods. There was conducted a general clinical, dental, laboratory examination of 127 children with type 1 diabetes mellitus aged 7 to 12 years with the endocrinopathy experience from eight months to ten years. The obtained data were compared with the results of the examination of 37 "healthy" and "practically healthy" children of this age category. When assessing the dental status of children, were used the hygienic index (Y.A. Fedorov, V.V. Volodkina, 1970), the CFE/ cf index (WHO Expert Committee, 1962), the simplified hygienic index OHI-S (Green, Vermillion, 1964). The intensity of the enamel demineralization processes was assessed using the enamel resistance test (V.R. Okushko, L.I. Kosavera, 1984) and vital staining (L.A. Aksamit, 1978). The electrometry of hard tooth tissues was carried out by the electrodiagnostic apparatus "Dent Est" (V.K. Leontiev, G.G. Ivanova, 1985).The laboratory diagnostics of the salivary indicators included the study of calcium (total, ionized), inorganic phosphorus, alkaline phosphatase, osteocalcin, parathyroid hormone, 25-hydroxyvitamin D3, lactoferrin. The microcrystallization and mineralizing potential of saliva were determined according to Leus P.A. (1997).Results.At the early stages of type 1 diabetes mellitus development children have a compensated and subcompensated form of the carious process, the increase in the enamel permeability, a slight predominance of the demineralization processes over the remineralization processes in solid tooth tissues. It indicates that self-regulation of the mineral metabolism mechanisms takes place while maintaining the physiological remineralizing properties of saliva. At a late stage of type 1 diabetes mellitus development a high intensity and decompensated form of the carious lesions are established as well as low structural and functional enamel resistance and pronounced processes of hard tooth tissues demineralization. The emergence of this complex in children with the experience of endocrinopathy for more than five years indicates the depletion of salivary gland functionality, the disturbance of mobilization salivary systems in response to the occurrence of the cariogenic situation in the oral cavity, the change in calcium homeostasis, the decrease in enamel resistance to organic acids and the absence of saliva crystallization.Conclusion.The growing positive dynamics of index growth in children with long-term type 1 diabetes mellitus, indicating the deterioration of the dental status, requires adherence to the principles of rational nutrition, quarterly professional caries preventive measures using modern and effective oral care products, the introduction of active forms of hygienic training and education taking into account the mineralizing potential of saliva as well as careful monitoring of the acquired manual skills.

Remineralization Potential of Lacto se- free and Plant based milk on Enamel surface of Human teeth subjected to Energy Drinks

Objective: Multiple etiological factors contribute to the process of erosion and destructionof enamel. Among which, carbonated soft beverages and energy drinks are the most aggressiveextrinsic causes. The consumption of milk whether bovine or plant based highly contributes to theremineralization process.Design: Thirty five freshly extracted sound human maxillary first premolars were used andrandomly divided into the following groups; Group I (Control group): included 5 teeth immersedin distilled water. Group II (Power Horse group): 15 teeth were immersed in 330ml of the drink.Group III (Cornelius group): 15 teeth were immersed in 330ml of the energy drink. After 10 days,the teeth were further randomly divided as follows (5 teeth each); Group IV (Power Horse +Lactosefree milk), Group V (Power Horse +Almond milk), Group VI (Cornelius +Lactose free milk) andGroup VII (Cornelius +Almond milk). Teeth of groups IV-VII were placed in both types of milk for5 days where the milk was changed every 2 hrs. The remaining teeth from groups II and III (5 teetheach) were kept in distilled water. At the end of the experimental period, the teeth were prepared forSEM examination, EDX and statistical analyses.Results: SEM examination showed that surface erosion was more aggressive in Power Horsegroup (II) when compared to Cornelius group (III). Furthermore, the results revealed betterremineralizing effect in groups IV and VI (lactose free treated) rather than those treated withalmond milk (groups V and VII ). EDX results presented statistically significant decrease in Caand P wt % in group II compared to group III . Statistically significant increase in Ca and P wt % ingroup IV in relation to group V and similarly, significant increase in group VI compared to groupVII were also detected.Conclusion: Energy drinks produce erosive defects of varying intensity on the enamel surfaceof human teeth. The intake of remineralizing agents; such as milk, immediately following everymeal containing acidic diet is mandatory to reverse the demineralization process.

Reducción de la variabilidad de un proceso de desmineralización de agua por intercambio iónico; para elaboración de bebidas gaseosas.

El enfoque del presente trabajo consistió en encontrar las soluciones necesarias para reducir la variabilidad, aumentar la capacidad y establecer un plan de mejora del proceso de desmineralización de agua para elaboración de bebidas. Para esto se realizó el diagnóstico del proceso y se reconocieron físicamente los elementos, insumos y equipos, desde la toma de la fuente hasta la fabricación de las bebidas. Las variables críticas de calidad las determinó control de calidad de acuerdo con pruebas realizadas en laboratorio y datos históricos. Se estableció dentro de la problemática que las dos variables críticas de calidad eran la dureza y alcalinidad del agua; se estudió el proceso con la referencia en estas dos variables para conocer las causas raíz que ocasionaban los problemas, se realizó mediciones para calcular la capacidad del proceso y realizar análisis de estabilidad, y se determinó las causas raíz del problema. La mejora incluyó la capacitación al personal, manual de arranque y manual de regeneración del equipo, además de controles en el proceso mediante cartas de control del tipo X-R. Se consiguió la reducción de la variabilidad, el aumento de la capacidad y mejora del proceso.

Remineralizing Effect of Xilitol, Juniperus Communis and Camellia Sinensis Added to a Toothpaste: An In Vitro Study

The aim of this study was to explore the remineralizing effect of toothpastes based on Xilitol, Camellia Sinensis and Juniperus Communis. An in vitro experimental study was carried out in an 18 human premolars sample, which were treated with one of the 3 evaluated toothpastes and a control fluoride one. The atomic percentages of Ca and P were evaluated by Energy Dispersive X-ray Spectroscopy (EDS). In addition, the enamel surface of treated teeth was visualized by Scanning Electron Microscopy (SEM). The evaluations were carried out in three stages: pre-treatment, after an artificial demineralization process and after the treatment with the toothpastes. In the statistical analysis, the one-way ANOVA and Pearson correlation tests were used. Xilitol and Juniperus Communis showed the greatest gain of P ions compared to the control group (p&lt;0.01). As for Ca, the group treated with xylitol-based toothpaste showed more ion gain compared with the control group (p&lt;0.01). In the Pearson correlation test between Ca and P, statistically significant correlations were observed in all groups (p&lt;0.01), ranging between r=0.7413 (Xylitol Group) and r=0.9510 (Control Group). We concluded that Xylitol paste showed the highest remineralizing property, both in the EDS analysis and in the SEM images.

Water Demineralization by Membrane Distillation Utilizing Cooling Water From Municipal Waste Incinerator

Abstract The membrane distillation performance was studied for production of demineralized water from surface water (river). Hot water from cooling water system of municipal waste incinerator was considered as an energy source for membrane distillation. The integration of membrane installation with such cooling water system allows to re-use up to 18 kW per 1 m2 of the membranes. The studies were performed with the application of polypropylene capillary membranes Accurel PP S6/2. The membrane modules were supplied with the feed heated to a temperature of 310 K and 330 K. The permeate fl ux obtained for these temperatures was 2.8 and 9.7 L/m2 h, and the distillate conductivity was 6 and 4 S/cm, respectively. The water demineralisation process was carried out for 1200 h without module cleaning. The behaviour of the permeate fl ux and distillate conductivity indicate that used membranes maintained their non-wettability over tested period. The performed SEM-EDS examinations confi rmed, that the deposits did not fi ll the pores and were mainly formed on the membrane surface. The scaling intensity was defi nitely smaller for lower temperature (310 K) of the feed. The amorphous deposits containing beside Ca also substantial amounts of the Si were mainly formed under these conditions, whereas at higher feed temperature dominated CaCO3 scaling.

Application of optical and spectroscopic technologies for the characterization of carious lesions in vitro.

The detection of the beginning demineralization process of dental hard tissue remains a challenging task in dentistry. As an alternative to bitewing radiographs, optical and spectroscopic technologies showed promising results for caries diagnosis. The aim of the present work is to give an overview of optical and spectroscopic properties of healthy and carious human teeth in vitro by means of Raman spectroscopy (RS), optical coherence tomography (OCT) and hyperspectral imaging (HSI). OCT was able to represent microstructural changes below the enamel surface and revealed increased scattering for white spot lesions and a white scattering trail for deeper lesions. HSI showed similar absorbance characteristics for healthy and demineralized enamel over the entire spectrum and a characteristic absorbance peak at 550 nm for discolored lesions. Already at early carious stages (white spot), we found a distinct loss of hydroxylapatite-related intensity at 959 cm-1 in demineralized regions with RS. Healthy and demineralized tooth surfaces can be distinguished at different signal levels by means of RS, OCT and HSI. The presented modalities provide additional information to the current clinical diagnosis of caries such as microstructural changes, quantification of the demineralization and imaging of caries-related chemical changes.

Employing different types of phytoestrogens improve bone mineralization in bisphenol A stimulated osteoblast

AimsPhytoestrogens and xenoestrogens act as agonists/antagonists in bone formation and differentiation. Strong bones are depending of the ability of osteoblasts to form new tissue and to mineralize the newly formed tissue. Dysfunctional or loss of mineralization leads to weak bone and increased fracture risk. In this study, we reported the effect of different types of phytoestrogens (daidzein, genistein and equol) on mineralization in hFOB 1.19 cells stimulated with bisphenol A (BPA). Main methodsCell mineralization capacity of phytoestrogens was investigated by evaluating calcium, phosphate content and alkaline phosphatase activity. Bone related markers, osteocalcin and osteonectin, responsible in maintaining mineralization were also measured. Key findingsBPA is significantly interfering with bone mineralization in hFOB 1.19 cells. However, the enhanced mineralization efficacy of daidzein and genistein (particularly at a dose of 5 and 40 μg/mL, respectively) was evidenced by increasing calcium and phosphate content, higher ALP activity, compared to the untreated BPA group. The quantitative analyses were confirmed through morphological findings. Osteocalcin and osteonectin levels were increased in phytoestrogens-treated cells. These findings revealed the potential effect of phytoestrogens in reverting the demineralization process due to BPA exposure in hFOB 1.19 cells. SignificanceWe found that osteoblast differentiation and mineralization were maintained following treatment with phytoestrogens under BPA exposure.

HYGIENIC ASPECTS OF ENDO- AND EXOGENIC METHODS OF PREVENTION OF CARIES AND THEIR EFFICIENCY IN THE REMINERALIZATION OF TEETH ENAMEL

According to the dental survey, the prevalence of caries in 33-45 years aged adults amounts to 98%. Studies of the effectiveness of prevention of tooth decay have shown the effectiveness of this direction. But the exogenous methods do not guarantee the restoration of the balance between the processes of demineralization and remineralization of the enamel. Demineralizing factors will prevail if the concentration of essential minerals in the mixed saliva is reduced. Therefore, it is necessary to develop endogenous techniques that will promote the process of remineralization of enamel and normalization of the ion-molecular balance. The aim of the study was to compare endogenous or exogenous methods in order to saturate mixed saliva with mineral complexes in preventing the development of primary demineralization of hard tooth tissue. Material and methods. The chemical composition of the mixed saliva sediment in 27 patients was analyzed by IR spectroscopy. To record the measurement of IR spectra, a Vertex-70 spectrometer (Bruker, Germany) and a PLATINUMATR full internal reflectance attachment with a diamond prism were used, as well as a clinical determination of the enamel remineralization rate (COSRE test) was performed. Results and Discussion. The relationship between the use of endogenous and exogenous methods of saturation of mixed saliva with mineral complexes and changes occurring in its molecular composition has been revealed, in favor of the effectiveness of endogenous methods.

Monitoring bone changes due to calcium, magnesium, and phosphorus loss in rat femurs using Quantitative Ultrasound

Bone mineral density is an important parameter for the diagnosis of bone diseases, as well as for predicting fractures and treatment monitoring. Thus, the aim of the present study was to evaluate the potential of Quantitative Ultrasound (QUS) to monitor bone changes after calcium, phosphorus, and magnesium loss in rat femurs in vitro during a demineralization process. Four quantitative ultrasound parameters were estimated from bone surface echoes in eight femur diaphysis of rats. The echo signals were acquired during a decalcification process by Ethylenediaminetetraacetic Acid (EDTA). The results were compared to Quantitative Computed Tomography (QCT) and inductively coupled plasma optical emission spectrometry measurements for validation. Integrated Reflection Coefficient (IRC) reflection parameters and Frequency Slope of Reflection Transfer Function (FSRTF) during demineralization tended to decrease, while the backscattering parameter Apparent Integrated Backscatter (AIB) increased and Frequency Slope of Apparent Backscatter (FSAB) showed an oscillatory behavior with no defined trend. Results indicate a clear relation between demineralization and the corresponding decrease in the reflection parameters and increase in the scattering parameters. The trend analysis of the fall curve of the chemical elements showed a better relationship between IRC and QCT. It was possible to monitor bone changes after ions losses, through the QUS. Thus, it is an indication that the proposed protocol has potential to characterize bone tissue in animal models, providing consistent results towards standardization of bone characterization studies by QUS endorsing its use in humans.