Is sealants or tooth grinding making my brackets come off?

A couple of weeks ago I had been babysitting and accidentely eaten a hard candy which my the the bracket on the right side of mouth on my molar come off....i can understand that but it does not have a wire on it and it did not come off until morning soooo? then i woke up this morning and the other sides bracket came off and i swear that i didn't do anything to mess it up...i had a chewy browny and pizza that was squishy and the crust wasnt hard...for lunch i had fries and chicken...and i didn't have breakfast...furthermore...i had tested each one b4 i went to bed to make sure they were on securely and i was not rough on them either...WHAT'S GOING ON?!! also do orthodontists make you pay for bracket replacement?