1. Charcoal dentifrices: A laboratory study of their safety and efficacy.
- Author
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BOWERS, ASHLEY N., TYRAKOWSKI, CHRISTINA M., YUKIKO KOIZUMI, SHAH, RAYHAN, GOPAL, PRERNA, and DUARTE, SIMONE
- Subjects
INDUCTIVELY coupled plasma mass spectrometry ,SODIUM fluoride ,HYDROFLUORIC acid ,METALS testing ,CYTOTOXINS - Abstract
Purpose: To compare charcoal-containing dentifrices (CDs) to non-charcoal containing dentifrices (NCDs) through the following experiments: potentially available fluoride, 1-minute fluoride release, pH, cytotoxicity, heavy metals, enamel fluoride uptake (EFU) and relative dentin abrasivity (RDA). Methods: Nine fluoride dentifrices; six CDs and three NCDs were tested (n= 3) for available fluoride, the amount of fluoride released within 1 minute, pH cytotoxicity, heavy metals, EFU and RDA. Four CDs and 1 NCD contained sodium fluoride (NaF) as the active ingredient whereas two dentifrices contained stannous fluoride (SnF2; 1 CD and 1 NCD), and two dentifrices contained disodium monofluorophosphate (Na
2 FPO3 , Or Na2 MFP; 1 CD and 1 NCD). Available samples were homogenized and diluted to l-in-100 in deionized water (DIW). Release samples were prepared as l-in-4 homogenized dilutions by mass in DIW. Available and release samples were measured in triplicate (n= 3) via fluoride ion-selective electrode (F-ISE) and ion chromatography (IC). ANSI/ADA 130 was followed for pH. L929 cells were cultured using the lactate dehydrogenase (LDH) assay and ISO 10993-5 Annex C MTT cytotoxicity test. Heavy metals testing was performed using a hydrofluoric acid digestion sample preparation method followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. EFU was performed on enamel specimens that underwent treatment with a CD slurry (l-in-4 dilution) following Test Method #40 of FDA Monograph 21. RDA was performed following ISO 11609 Annex A and the Hefferren method. Data was analyzed using one-way ANOVA followed by post-hoc tests (α= 0.05). Results: Available fluoride for all nine dentifrices was between ~93-102% of the labeled amount. The amount of fluoride released after 1 minute of homogenous mixing ranged between 75-107% of the labeled amount. The pH values of the nine dentifrices ranged from 6.5 to 7.7. Charcoal did not significantly contribute to cytotoxicity in L929 cells. The concentrations of each heavy metal (Hg, Cd, As and Pb) present in each of the nine dentifrices were < 1 ppm, indicating trace amounts. The CDs were not significantly more abrasive than the NCDs. The SnFi CD had the highest EFU value (644.2 ±131.7 ppm) followed by the NaF CD and the NaoMFP CD at 492.2± 69.5 ppm and 140.1± 28.1 ppm, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2024