Hi,
Dental cavity is a very common issue now a days.
There is no such anti cavity toothpaste in the market, only your regular two times brushing and flossing, Eating healthy foods like fruits, green vegetables etc, Limiting the consumption of acidic foods and beverages like tea and coffee, fizzy drinks etc and most important Limiting the consumption of sticky foods like pizza, chocolates, toffee etc. Look for a fluoridated toothpaste as fluoride plays an important role in keeping your tooth healthy.
Visit your concerned dentist every 6 months so your oral diagnosis can be done and treatment can be planned accordingly.
Regards.