Effects of ammonium hexafluorosilicate application on demineralized enamel and dentin of primary teeth

Abstract

Silver diamine fluoride (Ag(NH 3 ) 2 F)arrests caries but stains teeth black. To overcome this drawback, we applied ammonium hexafluorosilicate (AHF; (NH 4 ) 2 SiF 6 ) and observed changes in the color and structure of demineralized enamel and dentin of extracted primary teeth. Enamel and dentin were demineralized in 10% EDTA solution for 90 s followed by 35% phosphoric acid gel for 60 s, then soaked in AHF solution for 60 s. Before analysis by scanning electron microscopy (SEM) and energydispersive X-ray spectrometry (EDS), enamel and dentin were demineralized in 10% EDTA for 90 s. Teeth were divided into 4 groups according to AHF application and artificial saliva immersion status and then examined. The data were statistically analyzed using one-way ANOVA and Fisher's PLSD test at a significance level of P < 0.05. AHF treatment did not cause visible discoloration. Enamel prisms and dental tubules appeared by demineralization were covered with precipitates by AHF application. A sphere-filled membranous structure was observed in the saliva immersion groups. EDS analysis showed that AHF application had no effect on enamel; however, F% and Ca/P ratio were significantly higher on dentin surfaces after AHF application without artificial saliva immersion. Further study on arresting caries treatment is required. (J Oral Sci 54, 267-272, 2012)

Effect of ammonium hexafluorosilicate application for arresting caries treatment on demineralized primary tooth enamel

“…However, the present results show that Ca/P ratio in groups C and D (i.e., those with AHF application) was significantly higher than in groups A and B (those without AHF application) (Tables 2 and 3). Both unground and ground enamel were more heavily demineralized by a 6-min period of phosphoric acid etching as compared with a 3-min period of phosphoric acid etching, as reported in a previous study (12). The 6-min exposure resulted in clearer and deeper enamel etching patterns (Figs.…”

“…Discoloration after SDF treatment resulted from silver phosphate precipi- tate that turned black after exposure to sunlight (5). Conversely, AHF-treated enamel and dentin of primary teeth did not show visible discoloration (12). Although long-term color change due to AHF application should be investigated in future studies, evidence indicates that AHF treatment alleviates behavioral problems related to SDF-induced tooth discoloration in children.…”

“…In a previous study (12), AHF application on enamel did not significantly affect the elemental content of enamel. However, the present results show that Ca/P ratio in groups C and D (i.e., those with AHF application) was significantly higher than in groups A and B (those without AHF application) (Tables 2 and 3).…”

“…It was hypothesized that AHF was dissolved by artificial saliva. As compared with dentin, the demineralized enamel surface was smooth, and the capacity of enamel as a reservoir for calcium fluoride and calcium fluoride-like minerals after AHF treatment might be low (12). Therefore, to produce a rougher enamel surface, and thus an effective reservoir, a longer etching time was used in the present study for both unground and ground primary tooth enamel.…”

“…In a preliminary study (12), AHF treatment did not cause visible discoloration on primary teeth. After AHF application, enamel prisms and dental tubules of partially demineralized primary teeth were covered with precipitates.…”