"We think of hot water and lemon as being the ultimate in health, but citrus fruits like lemon and lime are very acidic and can erode teeth enamel," explains Dr Thorley. This reveals yellow tissue below the surface, hence the appearance of yellow teeth.

Is lemon bad for teeth whitening?

Some people advocate brushing or rinsing with lemon juice to whiten teeth. But, lemon juice is actually citric acid and can harm teeth, causing them to lose calcium—which gives teeth some of their off-white color.

Does lemon juice stain teeth?

Lemon acidity can cause tooth erosion

As dentin is yellower in colour than enamel, tooth erosion also often leads to the appearance of stained or yellow teeth. As your enamel erodes it becomes thinner and this allows the yellower dentin that lies below the enamel to be more visible.