Impact of brushing with charcoal on tooth color and enamel loss: An in vitro study.

PURPOSE: To evaluate the whitening efficacy of charcoal powder compared to a whitening toothpaste and the surface loss using scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM). METHODS: 60 human extracted teeth were randomly assigned to two groups: Treatment (T, charcoal group: Premium Nature) and Control (C, whitening toothpaste group: Colgate Optic White). Teeth in the treatment group were brushed with a charcoal paste. Teeth shade was evaluated before and after the intervention. Lightness was assessed using both VITA classical shade guide and VITA Easyshade V. Changes within and between the group were evaluated by the paired-sample t-test and independent sample t-test. Surface roughness (Ra) of samples was performed using SEM, and to assess surface loss a CLSM was used. RESULTS: At baseline, there were no significant differences in teeth lightness, chroma, or hue between both the charcoal and the whitening toothpaste groups (P> 0.05). After 21 days of brushing, teeth brushed with the whitening toothpaste were significantly lighter (VITA Easyshade mean score: 78.34, SD: 8.397; VITA classical A1-D4 shade mean: 8.90, SD: 4.475) than the charcoal group (VITA Easyshade mean: 69.70, SD: 6.364; VITA classical A1-D4 shade mean: 11.77; SD: 3.421) (P< 0.001). In addition, there was a significant reduction in lightness (i.e., increase in darkness) within the charcoal group after the intervention (P< 0.001). There was no significant difference in chroma and hue between the charcoal and the whitening toothpaste groups (P> 0.05). There was no significant tooth loss nor roughness change (P= 0.867) for both groups when compared with natural tooth structure. Brushing teeth with the charcoal paste tested for 21 days had no effect on tooth lightness, chroma, or hue. Charcoal powder had no significant effect on tooth surface roughness. CLINICAL SIGNIFICANCE: The Premium Nature charcoal toothpaste tested had no tooth whitening effect.

Vitamin D modulates human macrophage response to Mycobacterium tuberculosis DNA.

Mycobacterium tuberculosis (Mtb) is a facultative intracellular pathogen that infects macrophages where it avoids elimination by interfering with host defense mechanisms, including phago-lysosome fusion. Endosomal Toll-like receptors (TLRs) generate Type I Interferons (IFNs), which are associated with active tuberculosis (TB). We aimed to explore if DNA from different Mtb lineages lead to differences in the inflammatory response of human monocytic/macrophage cells. THP-1 cells which express two inducible reporter constructs for interferons (IFNs) as well as for NF-κB, were stimulated via endosomal delivery of Mtb DNA as a nanocomplex with PEI. DNA from different Mtb phylogenetic lineages elicited differential inflammatory responses in human macrophages. An initial relatively weak IRF-mediated response to DNA from HN878 and H37Rv increased if the cells were pre-treated with Vitamin D (Vit D) for 72 h. RNAseq of THP-1 under different transformation conditions showed that pre-treatment with Vit D upregulated several TLR9 variants, as well as genes involved in inflammatory immune response to infection, immune cell activation, Type I IFN regulation, and regulation of inflammation. Vit D appears to be important in increasing low IRF responses to DNA from certain lineages of Mtb. Variations in the IRF-mediated response to DNA derived from different Mtb genotypes are potentially important in the pathogenesis of tuberculosis since Type I IFN responses are associated with active disease. The role of Vit D in these responses could also translate into future therapeutic approaches.