Effect of Cold Atmospheric Pressure Plasma Coupled with Resin-Containing and Xylitol-Containing Fluoride Varnishes on Enamel Erosion

Abstract

Purpose. Considering the suggested advantages of cold atmospheric plasma (CAP) in increasing the fluoride uptake by the enamel, this study aimed to assess enamel erosion following the application of helium CAP and two types of fluoride varnishes. Methods. The microhardness of 70 bovine enamel specimens was measured using a Vickers hardness tester. The specimens were randomly divided into 7 groups (n = 10): control, CAP (P), resin-containing fluoride varnish (RF), CAP + resin-containing fluoride varnish (PRF), fluoride varnish (F), CAP + fluoride varnish (PF), and erosion (E). The specimens in the control and erosion groups did not receive CAP or fluoride varnish. All specimens underwent erosive challenge 4 times/day using hydrochloric acid and artificial saliva except for the control specimens that remained in distilled water during the course of the study. After 5 days of erosive challenge, microhardness was measured again, and the percentage of microhardness change was calculated. Surface roughness of two specimens in each group was assessed by atomic force microscopy (AFM). Data were analyzed using one-way ANOVA followed by Tamhane’s post-hoc test. Results. The percentage of microhardness change in all groups was significantly higher than that of the control group. All groups showed significantly lower percentage of microhardness change compared with the E group except for the P group; no significant difference was noted in microhardness change of P and E groups. Other experimental groups had no significant difference with each other. Surface roughness was the highest in PRF and the lowest in the F group. Conclusion. CAP application had no significant effect on increasing the enamel resistance to erosion. However, enamel resistance to erosion increased significantly after fluoride varnish application alone or fluoride varnish application combined with CAP. No significant difference was noted between the two types of varnishes in this regard. CAP increased the surface roughness while fluoride varnish application alone decreased the roughness.

Xylitol Fluoride Varnish: In Vitro Effect Analysis on Enamel by Atomic Force Microscopy

“…These results are consistent with the results of other studies [ 37 , 38 , 39 , 40 , 41 , 42 ] which have shown that varnishes containing sodium fluoride are effective in modifying the roughness of the enamel surface. Other studies that have used the AFM analysis technique [ 42 , 43 , 44 ] have found that the hardness of dental hard tissues decreases after the use of fluoride varnishes. Additionally, fluoride varnish is effective in reducing enamel demineralization [ 45 , 46 ].…”

Vickers micro-hardness study of the effect of fluoride mouthwash on two types of CAD/CAM ceramic materials erosion

“…Microhardness is usually related to materials' mechanical properties and is an essential property of dental materials associated with compressive strength and resistance to softening [ 10 ]. Low cost and being easy application may cause this method to be popular in evaluating dental erosion [ 11 ].…”

Atmospheric Pressure Plasma Activation of Hydroxyapatite to Improve Fluoride Incorporation and Modulate Bacterial Biofilm

“…In 2018, Kim et al showed that using a cold atmospheric plasma (CAP) device, the fluoride uptake and retention from a 1.23% acidulated P fluoride gel, along with the acid resistance, were improved on enamel specimens [ 10 ]. In 2021, Khoubrouypak et al [ 28 ] reported the effects of helium CAP on enamel erosion when testing two fluoride varnishes (Enamelast and FluoroDose), both having concentrations of 22600 ppm F. Based on the mechanisms reported in the literature regarding the improvement of fluoride varnishes’ efficiency by CAP, two assumptions were considered at the beginning, but only the second was assumed for their study. The first one was previously reported by Kim et al [ 10 ].…”

“…Their results showed that for an argon plasma, the wettability of the dentin substrates increases, but with no differences in the contact angle values for different input powers or for treatments longer than 30 s. For the enamel surface, the contact angle values decreased from 24.0 ± 5.5° to 3.3 ± 1.0° after 30 s of plasma treatment. Based on the study results, Khoubrouypak et al concluded that the CAP treatment did not significantly increase the enamel erosion resistance, which was mainly assigned to the fluoride varnish application [ 28 ].…”