It’s a common dental problem. Plz get your cavities filled so that they do not progress further abcs maintain your oral hygiene by learning proper brushing technique

Hi As you said there are 2 to 3 cavities in your mouth You need to maintain good oral hygiene first and then get all effected teeth treated so that they don't cause of pain and then follow all precaution Thanks Team Smmylo Dental & Implant care Gurgaon

Mostly coz of food habits Brush twice Wash mouth after having anything Use mouth wash

These can happen due to food habits, weak tooth structure (such as enamel dentine), improper brushing, excessive amount of fluoride taking, genetically inherited issues, general enamel hypoplasia etc. The less immunity is not the issue, once enamel is already made it cannot be developed again and tooth structure develops within the jaw bone within 15 year's old, as a result as immune treatment can't effect your teeth structure. If immunity falls then gum problems, ulcer of the mucus membrane etc develops but tooth structure can't be compromised so it's very unlikely of less immunity to cause cavities.

Hi, You need to get a routine dental check up every 6 months. Brush your teeth twice a day. Gargle your mouth with water after every meal.