Is it safe? Medical professionals are warning against using a DIY whitening trend that involves smearing a charcoal-derived black mixture on teeth. The method, which dentists say may lead to enamel deterioration and tooth erosion, became an online sensation this month after YouTube user Mama Natural posted a video that details its execution began striking fire online. As of Monday morning, it had amassed more than 1.5 million views. In the video the host Genevieve brushes her