All teeth in a 3 year old are primary milk teeth and are going to be succeeded by permanent teeth from 6 years onwards....

As these are milk teeth which you are taking about so they will replace by permanent teeth at a certain age by that time you have to take the child to the dentist or a pedodontist to remove the caries & restore the teeth for years

All the teeth in a 3 year old child's mouth are milk teeth which have two functions....to help the child chew and to maintain space for the permanent teeth until they are ready to erupt.  At age 6 without any tooth falling four new molars will erupt from behind these teeth. If your child's teeth are decayed and in bad condition these permanent molars may also get decayed soon. These are the 1st molars which do about 80 percent of you chewing. I would strongly recommend to get decays in milk teeth filled or treated. And do not take it lightly alter child's eating habits and hygiene habits.

Hi Ya from 6 years onwards the milk tooth in lower front will shed off followed by upper tooth. All molars too will shed subsequently. Advice for night brushing and mouth rinse to avoid cavity formation.

No teeth once destroyed by caries cannot regenerate themselves however these primary teeth will be replaced by permanent teeth from the age of 6 yrs to 12 yrs. Till then it is very important to undergo comprehensive dental treatment of all the decayed teeth for the physiological well being of the child.

Teeth do not regrow but after milk teeth are lost new set of permanent teeth will erupt from the age of 6 years onwards. But it is important to preserve milk teeth so that new teeth come in a proper position