Loosening of teeth indicates a condition called periodontitis meaning inflamation of teeth and gums. U may require a periodontal flap surgery, to prevent further damage, where a dentist would reflect the gum flap, remove infected or week tissue and put a bone grafting if needed and suture it back. So that your gums and teeth with regain strength.
It's safe in concentration prescribed but advisable not to use for long avoid in between n than can b restarted. If accidentally ingestion in small quantities doesn't have any side effects. In research mice has shown carcinoma tic changes in higher concentration n long duration