Hi, teeth become loose if they loose support from the surrounding tissue called periodontium which includes the bone & gums surrounding the teeth. Usually it is a result of progressive disease affecting the periodontium. I will advise you to visit a periodontist (dentist specializing in gum diseases) who will be able to advise you appropriately. All the best.
Health Tips
Start taking exceptional care of your oral hygiene by regular brushing, flossing & rinsing.