Dear Lybrate user, apple cider vinegar is know to be used a s a mild mouthrinse but it does not cause teeth whitening
with single use. MOREOVER, IT IS VERY ACIDIC IN NATURE SO IT SHOULD NOT BE BROUGHT IN CONTACT WITH THE TEETH WITHOUT DILUTING. High acidic nature can lead to enamel damage and erosion. Use a very gentle/soft toothbrush for brushing after waiting for 30 minutes. You can dilute one part apple cider with 2-3 parts water and rinse your mouth with it. Be careful as to not to follow it as a long term daily routine. If you are not satisfied with the natural color of your teeth, better to go for proper treatment options like bleaching
rather than using a product whose use and benefits for teeth are not documented properly. Otherwise, it's very good for your body health.