3 year old grey tooth

[itchyface14]

Today I noticed one of the front teeth looked a little grey. At first I thought maybe she colored it some how with a marker or a crayon because I just noticed out of no where. So bruhsed her teeth and looked closer, but it just has a grey tint to it. My mom said maybe it was from injuring it. She did fall on her face about 2 1/2 weeks ago, which resulted in a fat lip with a cut on it. She did't cut the inside of her lip on her tooth, but I guess her mouth could of been open and the tooth hit the floor. Could that be the reason for it? Would it of taken it that long to become discolored? It's possible she hit it on something else more recent that I was on aware of. The tooth and the surrounding gums don't hurt her. Her gums the normal color.
Random..but, she only will use those pink gel fruity toothpastes. I know they clean her teeth, but they don't really freshen her breath all that well. She says the childrens minty paste kind is spicy. I've tried to teeth her to use childrens mouth wash, but she would swallowed most of it. Does anyone have any suggestions?  

I left her dentists office a message, but they have't returned my call yet and I'm just curious.    

[drcm]

Trauma can cause the tooth to die.  When the tooth dies, the nerve in the middle of it dies and breaks down.  You have little tunnels in your teeth running from the nerve to the top layer of enamel.  The broken down nerve can run into these tunnels and ultimately bruise them leading to discolouration.  If this is a children's tooth it will fall out itself.  If this is an adult tooth you could eventually consider getting the root filled and then bleach the tooth from the inside.

[stateofconfusion]

Grey teeth usually signify trauma...maybe she fell or hit her self while playing or maybe was hit while playing.  if she's really young and the 'grey tooth' in question is a primary tooth, don't worry about it much, it will fall out and the permanent one will grow in... USUALLY with no problems.  Do keep watch of it though...all the NORMAL things can sometimes come with ABNORMAL things.   but I'm almost certain it's from the fall...