Report Abuse. Braces, I guess are in a way bad for your'e teeth because of the glue and metals in your mouth that can make you bleed unnaturally. But they are helpful and good because they straighten your teeth and can maybe even make ways to help you eat better.eport Abuse. Braces are not at all bad for your gums unless you don't brush them properly and floss. Braces do make your teeth looser because they are moving out of their normal position into a new position.