What is the direct answer?
Baking soda may scrub away some surface stain, but it cannot bleach the natural inner color of teeth or remove every cause of yellowing.
What does this question mean?
Yellow appearance can come from surface pigments, darker dentin beneath translucent enamel, tartar, decay, or enamel change. Treatment depends on the layer or condition involved.
What can you do next?
Use fluoride toothpaste and a soft brush, and have tartar removed professionally. Do not scrub hard or mix baking soda with acids, which can increase tooth wear.
When should you seek dental care?
See a dentist for one-tooth discoloration, injury-related darkening, pain, holes, sensitivity, or deposits that brushing cannot remove.
What should you ask the dentist?
Ask whether the color is stain, tartar, enamel, dentin, decay, or a restoration, and which whitening method suits your teeth and gums.

