1) Gingivitis ("inflammation of the gums") (gingiva) around the teeth is a general term for gingival diseases affecting the gingiva (gums). As generally used, the term gingivitis refers to gingival inflammation induced by bacterial biofilms (also called plaque) adherent to tooth surfaces. ...

1) Gingivitis ("inflammation of the gums") (gingiva) around the teeth is a general term for gingival diseases affecting the gingiva (gums). As generally used, the term gingivitis refers to gingival inflammation induced by bacterial biofilms (also called plaque) adherent to tooth surfaces.

2) Periodontitis, formerly known as Pyorrhea alveolaris, is the name of a collection of inflammatory diseases affecting the tissues that surround and support the teeth. Periodontitis involves progressive loss of the bone around teeth which may lead to loosening and eventual loss of teeth if untreated. Periodontitis is caused by bacteria that adhere to and grow on tooth surfaces (microbial plaque or biofilms), particularly in areas under the gum line. Periodontitis is very common in most populations but the severe forms of the disease are less common.
Important "risk factors" include smoking, poorly controlled diabetes, and inherited (genetic) susceptibility.