Investigation of Fluoride Release from Orthodontic Acrylic Plate

Abstract

Objective: This study aimed to investigate fluoride release, flexural strength and surface characteristics of three orthodontic acrylic resins (A) blended with (1) sodium fluoride powder (NaF), (2) calcium fluoride powder (CaF2), and (3) glass ionomer cement powder (GIC). Material & Methods: Acrylic resin was blended with NaF, CaF2 , and GIC to make orthodontic acrylic plates. Each sample group was divided into subgroups at fluoride concentrations 5%, 10% and 20%. The acrylic resin was cured in a round stainless steel mold and kept in a bottle with 10 ml. deionized water then kept in an incubator at 37oC. The deionized water, changed every day, was tested for fluoride release up to six mo by Orion machine. For the flexural strength test, the samples were cured in a stainless steel mold, 64 mm. long, 10 mm. wide and 3.3 mm. high according to standard of ISO 20795-2 and testing was done up to 6 mo in deionized water. Scanning electron microscope determined surface characteristics after being blended. Results: Fluoride release was observed from orthodontic acrylic plates blended with NaF, CaF2 and GIC. The results of the A-NaF and the A- CaF2 group decreased fluoride level greatly at day 2, but the A-GIC group was observed at day 7. The A-NaF group and the A-GIC group could not detect fluoride level after mo 4 and 2, respectively. The A-CaF2 group found greater long term fluoride release than the A-NaF and the A-GIC group especially at 20% concentration (up to six mo). Significant differences (p<0.05) of fluoride release level (ppmF) among the A-NaF, A-GIC, and A-CaF2 groups at 5% concentration in every time point from day 1 to the mo 5, but not significant in mo 6 similar to the 10% concentration comparison. Whereas, comparing the 20% concentration among groups, significant differences (p<0.05) were found between groups in all periods of time (from the day 1 to mo 6). When comparing the different concentrations of 5%, 10%, and 20% in each group, significant differences (p<0.05) were found in every concentration at every time period of the A-GIC group from day 1 to mo 2, in the A-CaF2 group from day 1 to mo 6 and in the A-NaF group from day 1 to mo 4. Conclusion: Fluoride release was observed from orthodontic acrylic plates blended with NaF, CaF2 and GIC. The longest duration of fluoride release from orthodontic acrylic plates was found in the CaF2 group followed by the NaF and GIC groups. The flexural strength in every group decreased over time. This result implied that the flexural strength decreased during fluoride release. The acrylic surface was seen to be porous in every period of the fluoride release process.

Evaluation of Fluoride release from orthodontic acrylic resin by using two different polymerizations techniques: An InVitro Study

“…They mixed NaF with orthodontic acrylic resin in three different amount of fluoride 5%,10% and 20% They detected that high level of fluoride release on the day 1, and fluoride level decreased greatly at day 2 in every concentration. The similar results "burst effect" was also reported by Upadhyay et al 2013 19 and Prapansilp et al 2017. 17 The mechanism by which fluoride release into an aqueous environment from all experimental materials supported the twophase diffusion theory.…”

“…12,14 The burst effect of fluoride release is crucial for inhibiting enamel and dentin demineralization as well as for the reduction of viability of bacteria that may have been left in the inner carious dentine. 19 The fluoride release is higher in 20% NaF than 10% for both polymerization type this is due to a higher amount of NaF that dissolved to fluoride ions. NaF is a very soluble salt and it is easily dissolved to free Na and F ions this is in agreement with previous study.…”

Microbiome-friendly PS/PVP electrospun fibrous membrane with antibiofilm properties for dental engineering

“…Also, fluoride can inhibit the activity of enolase, which can influence glycolysis and the production of phosphoenolpyruvate in S. mutans [ 44 ]. Moreover, calcium fluoride is less soluble than sodium fluoride, and CaF 2 becomes more soluble due to the formation of HF when pH decreases, maintaining the concentration of fluoride for a longer time [ 45 , 46 ]. Considering the widespread application of fluoride and high specific surface areas and porous structures of electrospinning materials, PS/PVP electrospun fibrous membrane carrying calcium fluoride nanoparticles was prepared to achieve slow fluoride release for better caries prevention and increase fluoride release during microenvironment acidification.…”

Assessment of the surface roughness and hardness of acrylic resin after incorporation of sodium fluoride salts (An In-vitro Study)

“…Forty-disc shapes of heat-cured samples of acrylic resins have been prepared by conventional methods. A silicon mold with a diameter of (12±0.1) mm and a thickness of 2(±0.1) mm (14) was used for the waxing of specimens that have been flasked Fig. (1,2).…”