Question about teeth?

my mother's teeth are very yellow, thats not the biggest problem though. I'm sure she has tons of cavities, but she has one tooth that has broken off a little and she says it feels like its about to fall out. Does that mean its rotten? We do not have enough money to go to the dentist, or no dental insurance. Is there anyway we can prevent it from falling out, or her getting that horrible disease, periodontitis. Please help
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It may be hard to search for, but try checking your area for local dental schools, as they usually run free clinics. In the meantime, I would recommend to her listerine, and if possible, some peridex (an oral mouth rinse that is generally prescribed to patients with abcess in the gums, usually its prescribed, sometimes not), and brushing and flossing twice a day.
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