Keep the oral cavity clean. After every feed clean the oral cavity. Since the child is 2 years of age a non operatory treatment approach can be employed (like fluoride varnish application) for the decayed tooth.

Check your feeding pattern.Dnt mix sugar into milk.Before bed Wipe teeth with a wet cloth.

Get it filled & it does not spread.but maintain ur oral hygiene by visiting a dentist once in 6 months..

Cavity in this tooth should be filled it solve the problem Regards

A cavity has to be filled else it keeps on spreading deep resulting in eventual pain and swelling. Considering the child's age, its best to get the filling done in the initial stages where the child doesn't feel by discomfort. To prevent cavities affecting other teeth you can brush her teeth at least once daily (twice best) after meals. Eliminate sticky sweets as much as possible from her diet. For further information and resolution you may visit a dentist at the earliest.