IADR Abstract Archives
Activated Charcoal-Containing Toothpastes: Chemically-Available Fluoride and pH in commercial formulations
Objectives: Activated charcoal-containing toothpastes have emerged as a novel and attractive formulation due to their potential putative beneficial effects for oral health. Due to its unspecific adsorbent properties charcoal might reduce the concentrations chemically-available fluoride found in toothpastes as ion fluoride (F-) or ion monofluorophosphate (FPO32-), from sodium fluoride (NaF) or sodium monofluorophosphate (Na2FPO3) salts, respectively. Furthermore, a low pH has been described to increase the adsorption potential of charcoal. To test this hypothesis, we assessed the concentration of available F and pH in charcoal-containing toothpastes marketed in the USA and in Chile.
Methods: Toothpastes (n=16) were acquired in duplicate with different lot number. According to the label, toothpastes contained NaF (68.8%), or Na2FPO3 (31.2%) as the source of F. Silica was used as abrasive in all tested products. Chemically-available F (total soluble F; TSF), total F (TF), and ionic F (IF), were determined using a calibrated specific F electrode coupled to a potentiometer. pH was determined on slurries using a calibrated pH-meter. Mean values of F and pH (n=4) were calculated for each toothpaste.
Results: In agreement with the manufacturers, ion FPO32 was exclusively found in samples labeled as containing Na2FPO3.TSF ranged from 970.5 to 1170.2 ppm F (µg F/g toothpaste), with only one sample slightly below 1,000 ppm F, considered the lower threshold for an anticaries effect by toothpastes. TSF concentrations were similar to the measured and declared TF concentrations. Overall, the pH of the fluoridated charcoal-containing toothpastes was basic (6.45 to 8.14).
Conclusions: Although we found that activated charcoal contained in fluoridated toothpastes does not decrease the concentration of available F, their stability overtime needs to be checked. In the absence of scientific evidence supporting their effectiveness on caries or potential erosive effects, activated charcoal-containing toothpastes should not be recommended to replace currently used F toothpastes.
Methods: Toothpastes (n=16) were acquired in duplicate with different lot number. According to the label, toothpastes contained NaF (68.8%), or Na2FPO3 (31.2%) as the source of F. Silica was used as abrasive in all tested products. Chemically-available F (total soluble F; TSF), total F (TF), and ionic F (IF), were determined using a calibrated specific F electrode coupled to a potentiometer. pH was determined on slurries using a calibrated pH-meter. Mean values of F and pH (n=4) were calculated for each toothpaste.
Results: In agreement with the manufacturers, ion FPO32 was exclusively found in samples labeled as containing Na2FPO3.TSF ranged from 970.5 to 1170.2 ppm F (µg F/g toothpaste), with only one sample slightly below 1,000 ppm F, considered the lower threshold for an anticaries effect by toothpastes. TSF concentrations were similar to the measured and declared TF concentrations. Overall, the pH of the fluoridated charcoal-containing toothpastes was basic (6.45 to 8.14).
Conclusions: Although we found that activated charcoal contained in fluoridated toothpastes does not decrease the concentration of available F, their stability overtime needs to be checked. In the absence of scientific evidence supporting their effectiveness on caries or potential erosive effects, activated charcoal-containing toothpastes should not be recommended to replace currently used F toothpastes.