In 1979 I had braces put on my teeth. A few years back my dentist added cement to the side of the front bottom tooth because I have receding gum lines. I lost my retainer that I had on my teeth since 1979 in January 2010 and now the extra cement that was added on fell off. My tooth is still intact but the gum is now lower because when the dentist put the cement on he pushed the gum down further. Do I need to get this repaired right away?