The right time to brush your teeth is after dinner? Yes and no.
Some foods that are high on carbohydrates and sugars, such as soda, bread or cookies, cause certain bacteria in your mouth that can attack the tooth enamel. Brushing right after eating such foods can help to prevent this bacteria from building up.
But there is another strong reason why you would not want to brush your teeth right after eating. If you have eaten anything acidic, such as wine or citrus fruit, you should wait for 30 minutes before you brush your teeth. Brushing earlier can actually damage the enamel as it is in an already weakened state. Enamel doesn’t grow back. Brush your teeth before having acidic foods and drink a glass of water later to wash away the acids from your mouth.
Information courtesy: www.livestrong.com