For bad breath, yellow teeth, sensitivity, and black stains, it is better to use a toothpaste that is specially designed for both sensitivity and stain control, as these help reduce sensitivity while gradually removing surface stains. Continue brushing twice daily with a soft-bristled brush, floss regularly, and use an antibacterial mouthwash to help control bad breath. However, black stains and heavy deposits are usually due to tartar buildup and cannot be removed by toothpaste alone, so a professional dental cleaning (scaling) by a dentist is the most effective solution. After cleaning, maintaining good oral hygiene and using the right toothpaste will help keep your teeth clean and reduce recurrence.