Chronic periodontitis is an inflammatory disease that causes the destruction of the tissues that support the teeth. It is caused by bacterial plaque accumulating at and below the gumline. The disease is characterized by pocket formation, attachment loss, and bone loss. It is usually slowly progressive and can range from mild to severe. Diagnosis involves measuring pocket depths, attachment levels, bleeding, and bone loss visible on radiographs. Risk factors include poor oral hygiene, smoking, diabetes, and genetic factors. Treatment aims to eliminate plaque and bacteria through nonsurgical methods like scaling and root planing or sometimes surgical procedures to reduce pocket depths and regenerate lost tissues.