Gingivitis promoting bacteria and sore gums

http://www.oramd.com/gingivitis/3-cureforgingivitis.htm
The classic signs and symptoms of gingivitis include red, swollen, tender gums that may bleed when you brush. The direct cause of gingivitis is bacteria found in dental plaque, which are soft deposits that form a biofilm adhering to the tooth surface or other hard surfaces in the oral cavity.