Toddler with black dental stains

Hello,

When my son was 1.5 yr old, he got some Antibiotics . Shortly after that, he started having black stains in his teeth. Now, he is about 2.5 yr old and many of his teeth have black stains. We have tried many types of natural toothpastes, including baking soda. But not much success. Kindly suggest what we can do, I'm very worried about his teeth. Want to prevent dental procedures at any cost.

He doesn't have pain in his teeth. He eats variety of foods, and is generally happy. But the stains are bothering me.

Bill Thompson in his book "Candida - Killing so sweetly" suggests using Turpentine for killing dental biofilms. He mentioned that his teeth did great after treatment with Turpentine. Could these black stains be some candida/fungus ?

Anyone used Turpentine for such dental stains ?

Thanks!!!