Determine the Effectiveness of Anacardic Acid and Stannous Fluoride as an Anti-erosive Agent

Background: The key goal of the study is to find out the effectiveness of anacardic acid and the stannous fluoride as an anti erosive agent. Objectives: To evaluate the erosive effect of Bio vinegar and antierosive effect of Anacardic acid and Stannous Fluoride. Methodology: The extracted teeth were collected for in vitro study. Three solutions were selected Bio vinegar, Anacardic acid, Fluoride to treat the extracted teeth to study and compare the anti-erosive effect. The sets of extracted teeth of ten each were grouped to be treated with different solutions. The set was immersed in Bio vinegar for 8 hours for erosive action. The second set of ten extracted teeth were immersed in anacardic acid for four days. The same set of teeth were treated with vinegar for 8 hours. The cross sectional view of stained teeth was viewed under Scanning Electron Microscope. The third set of teeth was immersed in stannous fluoride for four days and then treated with Bio vinegar for 8 hours. The cross sectional view of stained teeth was viewed under Scanning Electron Microscope. A comparison of anti-erosive effect of anacardic acid and stannous fluoride were studied under Scanning Electron Microscope. Expected Results: Determining a better effectiveness of Anacardic acid antierosive agent than stannous fluoride. Conclusion: Reduction in the level of erosion by the application of anacardic acid and stannous fluoride on extracted teeth exposed to carbonated drinks and assessment of erosive effect of carbonated drink on tooth.

Rapid destruction of planetary debris around white dwarfs through aeolian erosion

ABSTRACT The discovery of numerous debris discs around white dwarfs (WDs) gave rise to extensive study of such discs and their role in polluting WDs, but the formation and evolution of these discs is not yet well understood. Here, we study the role of aeolian (wind) erosion in the evolution of solids in WD debris discs. Aeolian erosion is a destructive process that plays a key role in shaping the properties and size distribution of planetesimals, boulders, and pebbles in gaseous protoplanetary discs. Our analysis of aeolian erosion in WD debris discs shows that it can also play an important role in these environments. We study the effects of aeolian erosion under different conditions of the disc and its erosive effect on planetesimals and boulders of different sizes. We find that solid bodies smaller than $\sim \! 5 \, \rm {km}$ will be eroded within the short disc lifetime. We compare the role of aeolian erosion in respect to other destructive processes such as collisional fragmentation and thermal ablation. We find that aeolian erosion is the dominant destructive process for objects with radius $\lesssim \! 10^3 \, \rm {cm}$ and at distances $\lesssim \! 0.6 \, \mathrm{R}_\odot$ from the WD. Thereby, aeolian erosion constitutes the main destructive pathway linking fragmentational collisions operating on large objects with sublimation of the smallest objects and Poynting–Robertson drag, which leads to the accretion of the smallest particles on to the photosphere of WDs, and the production of polluted WDs.

Enhancing the Anti-Erosive Properties of Fluoride and Stannous with the Polymer Carbopol

This in vitro study investigated whether Carbopol 980 polymer could potentiate the anti-erosive effect of solutions containing sodium fluoride (F) and sodium fluoride associated with stannous chloride (FS). The dissolution of hydroxyapatite treated with the experimental solutions (F [500 ppm F–], F + Carbopol [0.1%], FS [500 ppm F– + 800 ppm Sn2+], FS + Carbopol) was evaluated. Deionized water was the negative control, and a commercial mouth rinse (AmF/NaF/SnCl2; 500 ppm F + 800 ppm Sn2+; Elmex® Erosion Protection) was the positive control. The solutions were also evaluated in an erosion-rehardening protocol, with two treatments per day, using bovine enamel specimens (n = 15) and human saliva. The acid challenge was performed using 0.3% citric acid (pH 2.6) for 2 min. Microhardness was measured at different times: baseline, after the first erosive challenge, after treatment, and after the second erosive challenge. Based on microhardness values, the demineralization, rehardening, and protective potentials were calculated. The alkali-soluble fluoride on enamel surfaces was also measured. Data were analyzed using ANOVA and Tukey tests (α = 0.05). Groups treated with FS + Carbopol showed the lowest hydroxyapatite dissolution and the highest rehardening and protective potentials. The measurement of alkali-soluble fluoride on enamel surfaces was also higher in the FS + Carbopol group. Carbopol was able to significantly increase the protective effect of the fluoridated solutions in addition to optimizing the adsorption of fluoride on the enamel surface.

In Vitro Assessment of Erosive Effects of Some Common Soft Drinks on Dental Hard Tissues

Summary Background/Aim: The chemical nature of soft drinks is acidic, so they possess the capacity to cause hard tissue erosion. The aim of this study is to assess the potentially erosive effect linked to pH and titratable acidity of some common soft drinks on dental hard tissues in prolonged time exposure. Material and Methods: Seven types of soft drinks in Romanian market were selected for this study. The pH and Titratable acidity were determined. Twenty one human dental hard tissue specimens were immersed in 5 ml solution each for 336h. Every 48h weight loss was determined for each specimen and after 336h volume changes were calculated. Enamel microhardness was determined using a Microhardness Tester model HV-1000 and compared to normal enamel microhardness. Results: The pH values of beverages ranged from 2.37 to 3.1, showing no significant differences. All specimens presented color and surface texture modifications, weight loss and volume reduction. There were found significant differences between the mean values of weight loss and enamel microhardness of each type of specimens and type of beverages tested. The most representative findings were achieved by indentations done in specific zones on Sprite® immersed specimen. This result suggest that microhardness near the eroded surface was significant lower than in other zones. Conclusions: Data obtained have shown that all the soft drinks tested had an erosive effect, causing dental hard tissue dissolution. For prolonged time exposure titratable acidity may be a major predictor for erosive potential. Dental erosion may affect different levels of enamel causing decreased enamel microhardness.

Flow Erosion Resistance of Concrete - Interaction of High-Speed Water Jet and Concrete

In the paper, the resistance of concrete to the erosive effect of water from a water jet was monitored. The tests were performed on concrete without the addition of fibres and on concrete with the addition of polypropylene fibres and steel fibres. The water flow hit the concrete surface at an angle of 90°. The water flow rate was 1.1 l/min and the water pressure was 80 MPa. After blasting the concrete with water jet, no cracks in the concrete were observed and the intended rugged surface relief was created. Steel fibres remained firmly anchored into the cement matrix.