Acidic Erosion Research Articles

Novel Root Conditioner Apple Cider Vinegar versus Citric Acid on Teeth with Periodontal Disease: A Pilot In-vitro SEM Analysis

Introduction: Root biomodification in periodontal therapy aims at removing the smear layer and enhances the clot stability necessary for periodontal regeneration. Citric Acid (CA), EDTA, fibronectin has been used routinely. But if used injudiciously acidic erosion of the periodontal tissues might occur. Apple Cider Vinegar (ACV) an organic acetic has been reported to possess antimicrobial, anti-inflammatory and antioxidant effects. Aim: To assess the effect of smear layer removal and fibrin clot adhesion of ACV in comparison to CA on periodontally affected teeth. Materials and Methods: This pilot study was conducted at Sri Venkateswara Dental College and Hospital, Chennai, India, for three months, starting in January 2024 and ending in March 2024. 8 Teeth extracted due to periodontal reasons were cleaned, scaled and root planed. From the extracted teeth 16 dentin block samples were obtained, of which eight underwent CA testing (Control group) and eight underwent ACV testing (test group). The SEM analysis was done to assess the efficiency of smear layer removal and fibrin clot adhesion. Results: Under qualitative Scanning Electron Microscope (SEM) analysis, though ACV (50%) and CA (50%) group exhibited significant level of smear layer removal, complete dentinal tubule opening (RMSI score 2) was observed only in ACV category. In regard to Blood Element Adhesion Index (BEAI) both the groups demonstrated moderate fibrin clot adhesion (BEA score 2) in 50% of their samples. Considering both the parameters, root conditioning effects of ACV was better than CA. Conclusion: Teeth treated with ACV had a comparable effect as the CA in terms of root biomodification. This novel agent with several medicinal effects can be considered for future studies to determine its regenerative effectiveness.

Data-driven prediction method for shear capacity of corroded rectangular reinforced concrete shear walls under varied failure modes

The physical and mechanical properties of rectangular reinforced concrete shear walls (RRCSW) will deteriorate over time due to acidic erosion, causing changes in damage characteristics and a reduction in shear capacity under seismic loading. The aim of this paper is to develop a failure mode-based prediction method for the shear capacity of corroded RRCSW, as the existing formulas for calculating shear strength become invalid in such scenarios. Initially, a total of 2403 RRCSW samples with various corrosion levels and main design parameters were generated and simulated using the authors' previous numerical method to obtain a comprehensive database of shear capacity. Subsequently, an efficient damage mode identification method for RRCSW was established using the Random Forest algorithm, and its accuracy and applicability in identifying damage modes of corroded RRCSW were verified. Finally, the existing calculation formulas for RRCSW in flexure-shear and shear failure modes were selected and modified to consider the corrosion effect based on the shear capacity database. The comparative analysis revealed that the proposed formulas provide accurate predictions of the shear capacity of corroded RRCSW, making the results of this study invaluable for seismic design of new structures and seismic performance evaluation of existing structures.

Effect of three different remineralising agents on prevention against acidic erosion of primary teeth: an in vitro study.

This study aimed to evaluate and compare the protective effect of fluoride varnish (Enamelast™, Ultradent Inc., Cologne, Germany), casein phosphopeptide-amorphous calcium phosphate fluoride/CPP-ACPF (MI Paste Plus, GC Corp., Tokyo, Japan) and self-assembling P11-4 peptide (Curodont™ Protect, Credentis AG, Windisch, Switzerland), against acidic erosion of primary teeth. Forty primary anterior teeth were randomly assigned to four groups (n = 10): group 1: control, group 2: fluoride varnish, group 3: CPP-ACPF and group 4: self-assembling P11-4 peptide. After applying remineralising agents, except for the control group, all specimens underwent an erosive challenge of carbonated soft drink and artificial saliva for 15 cycles of 6s each at 6-h intervals for a day. Groups were compared in terms of surface microhardness, roughness readings, and surface scanning with an extra-oral scanner (D800; 3Shape A/S) before and after the erosive process. All experimental groups showed superior results than the control group regarding microhardness, surface roughness, and substance loss. The fluoride varnish group showed significantly favourable results in microhardness change. There was no significant difference between the experimental groups regarding surface roughness and enamel loss measurements. 5% NaF fluoride varnish, CPP-ACPF and self-assembling P11-4 peptide protect the enamel of primary teeth against erosion compared to artificial saliva alone.

Effect of acidic erosion on properties of solidified sewage sludge.

Solidified sludge can be regarded as a new type of earth cover material for domestic waste landfill. But the acidic environment result from the leachate in landfill is a potential threat to cement-based material. In order to evaluate the deterioration risk of solidified sludge in acidic environment, the leaching process of solidified sludge components under different pH conditions was investigated by taking Ni and Cr as the indexes of semi-dynamic leaching test. Under strongly acid environment (pH = 2), the leaching rate of Cr is significantly higher than that in the weakly acid environment or nearly neutral environment, and the diffusion coefficient increased by an order of magnitudes. The leaching and diffusion coefficients of Ni undergo a small influence from the adding amount of cement and pH value. Both Ni and Cr have relatively low migration ratio.

Corrosion failure analysis of hollow copper coil used in generator internal cooling water system operated at low-oxygen/neutral water chemistry

This paper reports the corrosion failure analysis of hollow copper coil used in generator internal cooling water (GICW) system operated at low-oxygen/neutral water chemistry in a nuclear power plant. Optical microscope, 3D surface profiler, SEM and tube endoscope were used to characterize the surface morphology of the copper coil. XRD, XPS, EDS and TOF-SIMS were used to identify the chemical composition of the corrosion products. The results show that the copper coil is seriously corroded and plugged. The corrosion products are mainly composed of CuO, Cu(OH)2, Cu2O and CuCO3·Cu(OH)2. This failure is attributed to O2 leakage and CO2 leakage during GICW system operation and shutdown. Their negative effects on the system are then revealed combined the thermodynamics analysis and the field evidences. The low-oxygen/neutral water chemistry requires stringently stable GICW water quality condition, whereas it was markedly changed by the leaked O2 and CO2. Thereby, the passive film was destabilized by phase transformation of the corrosion products and acidic erosion, resulting in the release of copper compound particles and subsequent system plugging. Further, suggestions for the field operation are drawn from this failure analysis. This case study can serve as a warning and a guidance for the safe management of GICW system.

Effect of citric acid erosion on enamel and dentin and possible protection by a novel bioactive borate adhesive system

ObjectivesThis study examined the ability of a borate adhesive to protect enamel/dentin surfaces from acidic erosion and its effect on the shear bond strength (SBS) of enamel/dentin to resin composite. Materials and methods180 human enamel/dentin specimens were utilized. Enamel buccal surfaces were etched with phosphoric-acid then divided into: (EBG) borate glass adhesive group; (ERS) resin-adhesive system group; (EF) fluoride gel 1.23% group, and enamel control (EC) group; followed by bonding to orthodontic-buttons. The dentin specimens were conditioned by EDTA (Ethylene-diamine-tetra-acetic acid) and divided into: (DBG) borate glass resin, (DRS) resin adhesive; (DDA) group had a dentin-desensitizing agent VivaSens (VivaDent, Liechtenstein) and (DC) control group. The treated enamel/dentin specimens had their SBS to composite. The enamel/dentin specimens were exposed to 1% citric acid (18 min). Enamel/dentin specimens were examined by (SEM/EDS) scanning-electron-microscope equipped with electron-dispersive-spectroscopy and (FTIR/ATR). Analysis-of-Variance (ANOVA) was used to compare the SBS and Wilcoxon-signed-rank test was used to compare the enamel/dentin areas protected by the applied agents before/after erosion (p = 0.05). ResultsThere was no significance difference in SBS among all groups except for (DDA) group that showed significant decrease p < 0.05. (EBG) and (DBG) groups were the only groups significantly protected enamel and dentin from erosion p < 0.05. FTIR/ATR showed that erosion altered the chemical structure of (DRS), (DDA), and (DC) groups but did not affect the other enamel/dentin groups. Degree of conversion of the borate-adhesive system was acceptable. ConclusionThe Borate adhesive system released calcium and phosphate compounds that decreased the erosive activity of the citric acid resulting in protecting simulated dentin-hypersensitive areas and enamel from erosion without affecting the SBS to resin-composite. Clinical significanceA Borate adhesive system can be adopted as a therapeutic agent in a fully integrated program for protecting dentin-hypersensitive areas and in enamel next to orthodontic fixed appliances.

Chemical initiator-free synthesis of Poly (acrylic acid-co-itaconic acid) using radiation-induced polymerization for application in dental cements

Glass ionomer cements (GICs) have been explored by the researchers around the world for their applications in dentistry because of numerous advantages such as their distinctive clinical properties e.g., anticariogenic properties, chemical adhesion to tooth surface and biocompatibility. However, the GICs prepared through the conventional chemical polymerization methods suffer from many disadvantages including release of unreacted monomer and toxic initiator into oral cavity. Therefore, in the present work, attempts were made to synthesize the polymer to be used in GICs using toxic initiator-free γ-irradiation technique. Different molar ratios of acrylic acid and itaconic acid were polymerized using Co-60 γ-source to produce Poly(acrylic acid-co-itaconic acid, PAA-co-IA). The synthesized copolymers, were characterized by FTIR, DSC and TGA. Compressive strengths of GIC specimens formed by incorporating fluoro-aluminosilicate (FAS) glass with synthesized copolymers, were investigated after storing for 1, 7, 14 and 28 days in distilled water. FESEM was performed to study the surface morphology of the cements. The working and setting time were determined as per ISO4049. The copolymers PAA-co-IA were synthesized via γ-irradiation method to form GIC. The results show that DC/PAA-co-IA/2:1 have higher Compressive Strength (CS) of 157.65 ± 4.02 M Pa as compared to control. High acidic erosion stability was observed, which was in agreement with the FESEM studies showing lower cracks and voids. Thus, γ-irradiation polymerization technique was initiator-free, facile and proficient for the synthesis of copolymers used in preparing GICs.

Experimental study of the sequential porosity evolution of sandstone under acid erosion

To comprehensively understand the evolution of sandstone porosity during sandstone matrix acidizing is of significance to the petroleum exploration. In this study, a self-designed experimental apparatus was applied to simulate the sequential water-rock reactions of sandstone under acidic erosion. A combination of methods, including the ultrasonic velocity measurement, low-temperature nitrogen absorption tests and high pressure mercury injection (HPMI) measurements, scanning electron microscopy (SEM) imaging and computed tomography (CT) scanning were used to analyze the characteristics of porosity. The X-ray diffraction (XRD) and X-ray fluorescence (XRF) was applied to analyze the variations of minerals and elemental content in the sandstone specimens, an acidity meter and coupled plasma mass spectrometry (ICP-MS) was used to measure the chemical parameters change in the reacted solution. The results show that, the acidic erosion significantly increased the porosity abundance and decreased the minerals and elements content in the sandstone specimens, and improved the aqueous elemental Ca, Na, K and Mg concentrations in the reacted solution. These effects of acidic erosion decreased with increasing reacted distance. The porosity enhancement can be primarily attribute to the depletion of minerals in sandstone, and the reduction of acidic effect is not only due to the acid consuming, but also associated with the different sensitivity of minerals in response to H+. This study can provide some experimental references to sandstone matrix acidizing, and recommend a useful tool for further research works.

Restorative Materials Exposed to Acid Challenge: Influence of Temperature on In Vitro Weight Loss.

Consumption of acidic beverages and foods could provoke erosive damage, both for teeth and for restorative materials. Temperatures of consumption could influence the erosive effects of these products. The aim of this in vitro study is to assess the influence of an acidic challenge on the weight loss of different restorative materials. Resin composites and glass-ionomer cements (GIC) were tested. The medium of storage was Coca-Cola (Coca-Cola, Coca-Cola Company, Milano, Italy) at two different temperatures, 4 and 37 °C, respectively for Group A and Group B. For each group, nine specimens were prepared for each material tested. After 7 days, weight was assessed for each sample, and the percentage weight loss was calculated. For all the resin composites (Groups 1–13), no significant weight losses were noticed. (<1%). Conversely, GICs (Groups 14 and 15) showed significant weight loss during the acidic challenge, which was reduced in the case of these materials that included a protective layer applied above. Significant differences were registered with intra-group analysis; weight loss for specimens immersed in Coca Cola at 37 °C was significantly higher for almost all materials tested when compared to specimens exposed to a cooler medium. In conclusion, all the resin composites showed reliable behaviour when exposed to acidic erosion, whereas glass-ionomer cements generally tended to solubilize.

In Vitro Weight Loss of Dental Composite Resins and Glass-Ionomer Cements Exposed to a Challenge Simulating the Oral Intake of Acidic Drinks and Foods

Specific conditions of the oral cavity, such as intake of acidic drinks, foods, and drugs, represent a damage both for teeth as well as restorative materials. The aim of this in vitro study is to assess the influence of an acidic challenge on the weight loss of biomimetic restorative dental materials (composite resins and glass-ionomer cements, respectively). Seven products recently available in the marked have been tested in this study for the two kinds of materials, respectively. Resin composites were divided into Groups 1A–7A, whereas glass-ionomer cements into Groups 1B–7B. A total of six samples was considered for each group, among which two were stored into distilled water (control samples) whereas the other four were immersed into soft drink (Coca-Cola, Coca-Cola Company, Milano, Italy) for 7 days. Respectively, after 1, 3 and 7 days, weight was assessed for each sample and the percentage weight loss was calculated. For all the composite resins (Groups 1A–7A), no significant intergroup or intragroup differences occurred for the weight loss values (p &gt; 0.05). Conversely, all glass-ionomers (Groups 1B–7B) showed a significant and progressive weight loss after 1, 3, and 7 days of acid challenge (p &lt; 0.05) (intragroup differences). This reduction was significantly lower in case of GC Equia Forte + Coat and ChemFil Rock, with respect to the other cements (p &lt; 0.05) (intergroup differences). In conclusions, all the biomimetic composite resins showed a reliable behavior when exposed to acidic erosion, whereas glass-ionomers cements generally tended to solubilize. However, the additional use of a protective layer above these latter materials could reduce this event. Despite these results appear to be interesting from a clinical point of view, future morphological evaluations should be conducted to evaluate the superficial changes of the materials after acidic explosion.

The Efficiency of Fluoride Bioactive Glasses in Protecting Enamel Surrounding Orthodontic Bracket

Objectives The aim of this study was to evaluate the protective effect of using four different fluoride bioactive enamel sealers against an acidic erosion challenge. Materials and Methods A sample of 50 freshly extracted sound upper premolars had their buccal surface bonded to 50 orthodontic brackets using Transbond PLUS color change adhesive; the first four groups had four compositions of fluoride bioactive glasses based on 37 mol% SiO2, 43.9-53.9 mol% CaO, 6.1 mol% P2O5 and CaF2, and 0-10 mol% of Na2O applied to their surfaces and the fifth group served as control (which was not treated by any bioactive sealer). All specimens were challenged by 1% citric acid for 18 minutes which was stirred by a magnetic stirrer. The enamel surfaces next to the orthodontic brackets were examined by SEM. The Wilcoxon signed-rank test was used to compare the area covered by the fluoride bioactive pastes before/after erosion (p < 0.05). Samples from the layer formed on top of the examined teeth were tested before/after erosion to be examined by the attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR/ATR). Results The FTIR/ATR test showed that fluoride bioactive pastes' applications resulted in the formation of a hydroxyapatite-rich layer; the SEM analysis showed that the aforementioned layer significantly resisted erosion challenge when compared to the control group (p < 0.05). Conclusions Fluoride bioactive pastes can efficiently protect the enamel surfaces next to orthodontic brackets from acidic erosion challenges.

Effects of temperature and acid solution on the physical and tensile mechanical properties of red sandstones.

Recent infrastructure development in China and other developing countries has attracted global attention. As a control project of traffic engineering, tunnels also have rapidly increased. However, fire accidents induced by traffic accident or gas explosion frequently occur in tunnels, causing irreversible damage to the tunnel rocks. Moreover, the corrosive effects of acid rain or polluted groundwater have a long-term effect on the tunnel and surrounding rocks. In this paper, physical and thermophysical properties tests as well as Brazilian splitting test were conducted on red sandstone specimens after heating at a variety of different temperature and acidic solution erosion. The responses of surface features, mass, P wave velocity, porosity and thermal conductivity, and the tensile strength of the red sandstone were compared and analyzed. In addition, the effects of high temperature (25-1000°C) and acidic solution on microscopic structures, defect morphology, and mineral reaction of the red sandstone were observed and analyzed. The experimental results show that high temperature and acidic chemical solution significantly affects the physical and mechanical properties of the rock mass. The typical parameters, such as surface features, mass and P wave velocity, porosity, thermal conductivity, and tensile strength, are closely affected by acidity. In addition, we observed that the physical properties of red sandstones change with temperature and can be divided into three stages, and at 300-800°C stage, they significantly declined. The results provide a basis for rock damage and failure induced by fire and acidic groundwater seepage in tunnels.

ХАРАКТЕР РАСПРЕДЕЛЕНИЯ РЕДКОЗЕМЕЛЬНЫХ ЭЛЕМЕНТОВ В МЕЗОЗОЙСКИХ ОСАДОЧНЫХ ПОРОДАХ НИЖНЕГО ПРИАМУРЬЯ

The article presents original data on the contents of rare earth elements (REE) and characterizes their distribution in Mesozoic sedimentary rocks of the Lower Amur region. The author compares various parameters of the studied rocks with similar parameters in the standards of the same rocks. The stratigraphic divisions made on the M-54-I sheet of the 1:200,000 scale State Geological Map belong to the Amur (or Chayatyn) subzone (SFPZ) of the West Sikhote-Alin Structural-Formation Zone (SFZ). Among them, the Zhorminsky (K1 zm) strata, Silasinsky (K 1-2 sl) and Utitsky (K2 ut K2) formations are distinguished. The stratons are composed of sandstones and siltstones in different ratios. They also contain conglomerates, tuffs of different composition, and andesites. The REE content in siltstones is higher than in sandstones. Higher concentrations of elements were found in the studied rocks relative to the rocks of the Caucasian Folded System (CC). Compared to the aleuropes of the Russian platform, the sandstones of Priamurye subzone have less REE content, and the siltstones have more. Compared to PAAS (post-Archean Australian shale), the REE content is less. Chondrite normalized REE contents. The trend of the charts is negative. The same behavior of elements is characteristic of the distribution spectra in the studied sandstones, siltstones, RAAS, aleuropesstones of the Russian platform, and rocks of the Caucasian SS. In most of the rocks presented, the LRSE/TRSE is higher than 8, this indicates that the sedimentation basin of detrital material has a predominantly acidic composition. There is a significant negative europium anomaly – from 0.34 to 0.71 in sandstones, and from 0.47 to 0.75 in siltstones. It also indicates the acidic rocks erosion. Consequently, a set of parameters determines the rocks acidic composition in the demolition areas.

HAP Coatings for Biomedical Applications: Biocompatibility and Surface Protection Against Corrosion of Ti, Ti6Al4V and AISI 316L SS

The implants used as cardio stents, orthopedic and dental implant may be subjected to biological corrosion. Uncoated implants can be corroded in various parts of the body due to acidic erosion and oxidation. This paper presents the findings of a coating technique for the deposition of hydroxyapatite (HAP) coatings on Ti, Ti6Al4V and AISI 316L stainless steel substrates (316L SS). HAP synthesized using the sol–gel technique have been successfully produced. The corrosion behaviors of uncoated and HAP coated substrates were investigated in Ringer’s and 0.9% NaCl solutions. The HAP coatings obtained by the sol gel method are effective in preventing corrosion and increased the polarization resistance values compared to the uncoated samples. Surface structures and chemical composition of the coatings were investigated by scanning electron microscopy (SEM) and energy diffraction X-ray (EDX) methods. SEM images of HAP coated substrates show cauliflower-like structures on the surface. Furthermore, the HAP coatings formed do not completely cover the surface. EDX analysis of HAP coated substrats were determined that there were Ca, O and P as well as oxides on the surface. The obtained HAP powder was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods. In XRD analysis, it was analysed that HAP powder consisted of CaP and HAP structures. In addition, FTIR spectrum was determined that characteristic HAP absorption bands.

Reduction of Acidic Erosion and Oral Bacterial Adhesion through the Immobilization of Zwitterionic Polyphosphoesters on Mineral Substrates

Phosphotriester- or phosphodiester polyphosphoesters (PPEs) bearing phosphorylcholine (PC) groups were newly synthesized and coated on hydroxyapatite (HAp) to form nonfouling mineral substrate surf...

Strength and Surviving Probability in Grain Crushing under Acidic Erosion and Compression

AbstractSingle-grain crushing tests were carried out on limestone with nominal particle sizes of 2.5, 5, and 10 mm to investigate the effect of particle size and acidic erosion on grain strength, c...

45S5 Bioglass paste is capable of protecting the enamel surrounding orthodontic brackets against erosive challenge.

OBJECTIVES:This study aimed at evaluating the effect of using a 45S5 bioglass paste and a topical fluoride as protective agents against acidic erosion (resembling acidic beverage softdrinks intake) for enamel surrounding orthodontic brackets.MATERIALS AND METHODS:Sample of 21 freshly extracted sound incisor and premolar teeth was randomly divided into three equal groups: a bioglass group (Bioglass) (NovaMin, 5-mm average particle, NovaMin Technology), a Fluoride group (Fluoride) (Gelato APF Gel, Keystone Industries), and a control group (Control). Orthodontic brackets were bonded to the utilized teeth usingMIP (Moisture Insensitive Primer) and Transbond PLUS color change adhesive. All specimens were challenged by 1% citric acid for 18 min. The top enamel surfaces next to the orthodontic brackets were examined by SEM-EDS. Wilcoxon Signed-Rank test was used to compare the area covered by the 45S5 bioglass paste before/after erosion P < 0.05.RESULTS:45S5 bioglass paste application resulted in the formation of an interaction layer that significantly resisted erosion challenge P < 0.05. The fluoride and control specimens showed signs of erosion of the enamel next to the orthodontic brackets (P < 0.05).CONCLUSION:45S5 bioglass paste can efficiently protect the enamel surfaces next to orthodontic brackets for acidic erosion challenges.

Chitosan-coated filter paper with superhydrophilicity for treatment of oily wastewater in acidic and alkaline environments

ABSTRACTThe separation of oil and water mixtures is an important issue in acidic and alkaline conditions. In this paper, the chitosan (CS)-coated filter paper was successfully fabricated for application in the field of oil/water separation by crosslinking filter paper with hydrophilic chitosan through a simple Schiff’s base reaction. The surface of the prepared CS-coated filter paper maintains superhydrophilic and low adhesive ability to oil in water. Besides, this filter paper can resist highly acidic erosion even concentrated sulfuric acid. Surprisingly, CS-coated filter paper can be efficiently applied on the separation of different types of oil/water mixtures in wide pH range conditions and exhibits excellent recyclability and antibacterial property. The antibacterial rate of CS fiber pure textile can reach 99%. The antibacterial rate of blended fabric is about 75%. This separation process has high potential for industrial oilfield wastewater treatment and separation in extreme environments.

Advising patients about acidic exposure and dental erosion

Advising patients about acidic exposure and dental erosion

Damage evolution mechanism and constitutive model of freeze- thaw yellow sandstone in acidic environment

The study on the damage evolution mechanism of freeze-thaw of rock sample in acidic environment is of great theoretical and practical significance to the analysis and prevention of freeze-thaw disasters in cold area. Taking the yellow sandstone as the research object, the freeze-thaw cycle experiments, the NMR system experiments, the chemical composition analysis experiments and the uniaxial compression experiments under acidic environments with different pH are carried out to analyze the physical and chemical characteristics of the yellow sandstone. The damage evolution equation and constitutive model of rock are studied based on statistical strength theory, Lemaitre strain equivalent assumption and damage mechanics. In this paper, the damage evolution equation of chemical freeze-thaw sandstone under load is established. The damage correction coefficient is introduced to modify the total damage of chemical freeze-thaw sandstone under load. The constitutive model is deduced and the model parameters are deduced by the combination of theoretical derivation and experiment. The results show that the rock damage is the result of the coupling of freeze-thaw cycles and acid erosion, and the freeze-thaw cycle is the main reason and acidic erosion is the secondary reason. The experimental parameters are brought into the constitutive model, and the reliability of the model under uniaxial stress is verified by comparing with the experimental curve.