Hung, Man

Kwok, Camy

Subramani, Karthikeyan

English

eCommons at Roseman University

printed bywww.postersession.comREFERENCESEvaluation of Remineralization of Artificial White Spot Lesions on Teeth Treated with Bioactive Glass Air Abrasion via SEM-EDXKwok C, DMD; Subramani K, BDS, MSc, MSPresented by Dr. Camy Kwok at Roseman Research Symposium, Henderson, NV on April 14, 2020.INTRODUCTION1. Arunachalam S, Sharan J, Sivakumar I, Jena AK. Orthodontic appliances and oral hygiene: Are we asking the right questions? Am J Orthod Dentofacial Orthop. 2018 Aug;154(2):155-156.2. Gwinnett AJ, Ceen RF. Plaque distribution on bonded brackets: a scanning microscope study. Am J Orthod. 1979;75:667–77.3. Imazato S, Ma S, Chen JH, Xu HH. Therapeutic polymers for dental adhesives: loading resins with bio-active components. Dent Mater. 2014 Jan;30(1):97-104.4. Milly H, Festy F, Watson TF, Thompson I, Banerjee A. Enamel white spot lesions can remineralise using bio-active glass and polyacrylic acid-modified bio-active glass powders. J Dent. 2014 Feb;42(2):158-66.5. Baino F, Hamzehlou S, Kargozar S. BAGes: Where Are We and Where Are We Going?. J Funct Biomater. 2018 Mar 19;9(1).MATERIALSPatients undergoing orthodontic treatment have greater difficulty maintaining adequate oral hygiene.1 There is an increased tendency for plaque accumulation around the brackets creating an environment conducive to growth of acid-forming bacteria.2 This acid subsequently results in the demineralization of the enamel resulting in WSLs.4 In severe cases, restorative treatment may be necessary after orthodontic treatment. • 40 Extracted Human Third Molars• Chemicals (Acetic Acid, Calcium Chloride, Potassium Chloride, Potassium Hydroxide, Potassium Phosphate, Sodium Phosphate)• 45S5 Bioactive Glass• Inert Epoxy• Diamond Polishing Paste• Air Abrasion Unit• Water Bath• Low Speed Saw• Variable Speed Grinder-Polisher• Sputter Coater• SEM-EDX• Electron Probe Microanalyzer• Scanning Electron MicroscopeRESULTS AND DISCUSSIONA statistically significant amount of remineralization was detected between the remineralized group and demineralized group, (t18)=-2.441, p=0.025. Bioglass air abrasion treatment was able to removethin layer of demineralized enamel. However, theGlass beads ranging from 30-90 microns could notbe retained on the surface of the enamel. Because of the mechanism by which bioactive glass functions;  the inability for retention therefore means that delivery via air abrasion is an ineffective means for initiating remineralization.However, as a coincidental finding, teeth treated with air abrasion were noted to be less susceptible to enamel fracture after the desiccation process necessary for microscopy. The additional therapeutic effect if curious and may have clinical value.Preparation of Samples1. 40 extracted human third molars were randomly divided into 4 groups (n=10/group) 1. Group 1 (Control), Group 2 (Demineralized), Group 3 (Air Abrasion), Group 4 (Remineralized)2. Group 1 was stored in Remineralization solution made of 1.5 mM calcium chloride (Sigma-Aldrich, US), 0.9 mM sodium phosphate (Sigma-Aldrich, US) and 0.15 M potassium chloride (Sigma-Aldrich, US) adjusted to a pH of 7.0 at intraoral temperature of 37°3. Group 2-4 were demineralized in 2.2. mM calcium chloride, 2.2 mM monopotassium phosphate (Sigma-Aldrich, US), 0.05 mM acetic acid (Sigma-Aldrich, US) adjusted to a pH of 4.4 using 1 M potassium hydroxide (Sigma-Aldrich, US) at intraoral temperature of 37°C for 96 hours in a laboratory waterbath (Fisher-Scientific, US). 4. Group 3-4 were then treated with bioactive glass (Velopex, UK) air abrasion. 1. Air abrasion was delivered at 2.6 bars at ¼ media output and ¾ water output from a distance of 5mm via an Aquacare air abrasion unit (Velopex, UK).2. 2 passes over treated surface Δ5 seconds.5. Group 4 was finally stored in remineralization solution consisting of 1.5 mM calcium chloride, 0.9 mM sodium phosphate and 0.15 M potassium chloride adjusted to a pH of 7.0 at intraoral temperature of 37°C for 7 days.Scanning Electron Microscope1. Forty enamel specimens were prepared one from each of the extracted molars. 2. Cut via low-speed diamond discs (Buehler, US) and refined with carbide burs (Komet, US) to 4 mm x 3 mm x 1 mm pieces. 3. Specimens were then gold coated for SEM-EDX to allow for electron dispersion. Gold coating was done via a Cressington Sputter Coater 108 Auto (Cressington Scientific Instruments, UK). 4. SEM-EDX was carried out via a Jeol JSM-5600 Scanning Electron Microscope (Jeol, USA). Measuring time was 60 seconds at resolution of 4.954 keV. 5. Elemental mapping was carried out in 1024x800 pixel matrix with 512 frames using INCA Microanalysis Suite (Oxford Instruments, UK). A 1 mm x 1 mm area analysis was done on each specimen.Electron Probe Micro-Analyzer1. One extracted human third molar from the demineralized and remineralized group each were selected2. Samples were mounted in inert epoxy (Buehler, US)3. Samples were bisected via low-speed diamond discs (Buehler, US)4. Samples were verified under light microscopy for smooth polish5. Carbon coating was done with a Denton DV-502A Vacuum6. Samples were mounted into a JXA-8900R Electron Probe Micro-Analyzer (Jeol, US)7. Configuration was set for analysis of Ca, P, F and Si8. Analysis was ran for 20 hours to complete mappingMETHODSFig. 2 Mechanism of bioactive glass induced bone regeneration5Ever since the introduction of bioactive glass into the market, researchers have attempted to incorporate it into various types of restorative materials like adhesives and resin restoratives.3Researchers have demonstrated that they are capable of devising a formulation for orthodontic adhesive incorporating bioactive glass that has clinically accepted bond strength while simultaneously increase the local pH.3 By increasing local pH, this bioactive glass resin has shown promise in mitigating the damage done by acid-forming bacteria and creating an environment more conducive to remineralization.3-4Fig. 1 White spot lesions post-orthodontic treatment as a result of acidogenic bacteriaFig. 3 Aquacare Air Abrasion Handpiece (Velopex, UK)Fig. 4 JXA-8900R Electron Probe Microanalyzer (Jeol, USA)Fig. 5 JSM-5600 Scanning Electron Microscope(Jeol, USA)Table 1: Boxplot of Ca:P content by groups: Control, Demineralized, Air Abrasion, Remineralized. The average ratio decreases with demineralization but increases through the course of treatment.CONCLUSIONWhile remineralization did occur during our study, it did not seem to be a direct result of bioactive glass treatment. The enamel remineralization potential via air abrasion delivery does not seem to be significant due to its inability to be retained on the surface of enamel. Remineralization seen was more a result of the natural process and removal of a thin demineralized layer.a bc dFig 6: SEM images of various samples (1 mm by 1mm images)a. Control, b. Demineralized, c. Air Abrasion, d. RemineralizedFig 7: EPMA images of Enamel Specimens. A. Remineralized, B. Demineralized

C11: Evaluation of remineralization of enamel of teeth treated with bioactive glass air abrasion via scanning electron microscopy with energy dispersive x-ray analysis and electron probe microanalysis

https://ecommons.roseman.edu/cgi/viewcontent.cgi?article=1096&amp;context=researchsymposium

C11: Evaluation of remineralization of enamel of teeth treated with bioactive glass air abrasion via scanning electron microscopy with energy dispersive x-ray analysis and electron probe microanalysis

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