Thank you for your question and welcome to Just Answer.
The fact that your two bottom front teeth are loose is a sign that you have periodontal disease which is a chronic, low grade infection of the gums surrounding the teeth. It is caused by bacterial plaque which lives in your mouth and attaches to the surface of the teeth both above and below the gum. If enough plaque accumulates under the gum, and remains for enough time, an infection will start. This infection starts in the small spaces between your teeth and gums. The gums react to this process by swelling up and loosening their grip around the individual teeth. This loosening opens up deeper spaces between the gum and tooth allowing for more debris, plaque and food to work their way into the deeper spaces. As the disease progresses, it slowly dissolves the bone around your teeth and, as it shrinks away, the gums can follow and your teeth can become loose. Many times, the patient is unaware of this disease because there is no pain involved until it gets to the advanced stage. Other symptoms of periodontal disease are bleeding gums (when brushing, or spontaneously), bad breath and receding gums. Many times, by the time an individual notices these symptoms, the disease has been active for quite some time, even years.
Periodontal disease can be treated and many of the symptoms can be reversed.
You need to go to a dentist that specializes in this disease, namely a Periodontist. He will diagnosis the severity of your condition and recommend treatment. Many times this disease can be treated with a thorough dental cleaning and root debridement. Once the plaque, infection and inflammatory toxins are removed from between your teeth and gums, any bad breath should go away, your gums will tighten back up and any bleeding should stop. In severe conditions, the pariodontist can splint or "glue" your loose teeth to the adjacent strong oned and bridge them together. Keep in mind that periodontal disease can not be cured; only treated.
After the initial treatment from the Periodontist, you will need to return a few times a year to him/her or to your regular dentist for regular dental cleanings. This will keep the disease at bay and prevent it from escalating to the degree that causes bone loss and further gum shrinkage.
Outside of keeping your teeth and gums as clean as possible, there is nothing you can do at home to tighten them back up.
I hope you find this information helpful. If you have any concerns regarding this issue that I have not addressed, please let me know and I will get back to you with more information.
George McKee DDS