once you have cavity filled, do you have to have it refilled later?

hi, im 19, and today, i got my 1st cavity out. i thought that was one of the worst experiences ever. luckily, it's made me really care for my teeth more, and i brush my teeth like 3x a day for like 3 min, and abstain from candy and soda. anyways, so since i got this cavity filled, i wont have to have it refilled later, would i? once you get it filled, it's permanent for life, and won't come off, assuming you take really good care of your teeth, etc, right? any dentists, dental assistants, or anyone that can help me with this? i cant believe i forgot to ask my dentist that earlier. im very curious. thanks
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A filling should be permanent, but sometimes they come out. You shouldn't chew ice or jawbreakers.
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