Lemon spoils your teeth because the enclosed acids attack the hard surface of the tooth enamel, corroding it. This process is called acid erosion and is one of the major reasons for dental sensitivity. If you really can’t do without lemon, you must be careful to drink it through the use of a straw, in order to minimize direct contact of the juice with your teeth. Then, importantly, the teeth should not be brushed immediately after eating lemon because the combination of lemon juice-toothbrush-toothpaste, especially if you use a paste that contains whiteners or granules, can be very harmful to tooth enamel.
It is therefore better to wait at least twenty minutes before brushing your teeth, making sure to rinse your mouth with water first. This is because drinking acidic drinks decreases the buffering power of saliva which tends to support tooth enamel from acid attack and lemon juice is a somewhat acidic food, as already mentioned, with a pH equal to 2.3 when it is identified that up to a pH equal to 6 we are dealing with acidic foods.
Therefore, although the consumption of water and lemon is a widespread custom and there are numerous people willing to say that we are talking about a drink capable of producing effects bordering on the miraculous, we must not minimize the possible negative effects it could generate on our body also in other cases than that of respect for the teeth.