WHAT ARE THE VARIOUS REASONS FOR TEETH TO BECOME LOOSE: The most frequent cause in adults for loose teeth is secondary trauma from periodontal (gum) disease. Bacterial plaque built up on teeth from poor oral hygiene causes a chronic infection that eventually weakens gum attachment to the teeth. A loose tooth is a late sign of this damage. Can a loose tooth tighten back up? Teeth naturally tighten themselves back up over a short period of time. If the affected tooth does not firm -up itself then you need to make an appointment at your dentist for an examination. Regular hygiene appointments will decrease the likelihood of your teeth getting loose. How can I prevent my teeth from being loose? Tips for tooth and gum health include: brushing the teeth thoroughly twice a day. flossing once a day. refraining from smoking. attending dental checkups and cleanings as often as recommended. wearing a properly fitted mouth guard while playing sports. wearing a bite splint, when nighttime grinding or clenching is an issue.