Also known as periodontal disease. It affects gums and the supporting bone. It is caused by sticky plaque and hard deposits of tartar. Gum disease caused by several factors, including poor oral hygiene, genetics, smoking, diabetes and manty other. If gum disease left untreated, it could easily lead to bone loss and subsequently the teeth become loose and eventually lost. As a matter of fact in the western world more teeth are lost due to gum disease than loss due to caries. It starts with gingivitis which is an inflammation- redness and swelling, and bleeding when brushing gingivitis. It can be cured with good oral hygiene and scaling.
The next stage is called chronic periodontitis. Some of the bone that supports the teeth is lost and the teeth became loose until they eventually have to be taken out.