A dead tooth — typically evident by its grayish color — is more than just a visual concern. If you don't deal with this dental issue promptly, you're apt to experience a multitude of problems. When a tooth ties, it has a lot of harmful bacteria around it. The bacteria can multiply to affect the health of your gums and even your jawbone. Teeth can sometimes die as a result of longtime neglect, but a traumatic injury is just as likely to result in dead tooth.