Periodontal pockets are areas of abnormal depth in the gingival sulcus, which is the small crevice of gum tissue that surrounds each tooth. The gingival sulcus teems with cellular material, chemicals, and food debris. When the periodontal tissues are healthy, the depth of the sulcus is shallow enough to allow it to be easily cleaned with a toothbrush and dental floss or other interdental cleaning tool. If gingivitis is present, inflammation may cause the sulcus to deepen, but this resolves when gingivitis is properly treated. When periodontitis is present, however, the connective fibers that usually hold the gums securely to the bones and teeth start to degrade and separate from the tooth, causing the pocket in the gingival sulcus to deepen. When the pocket deepens past a certain depth and is characterized by this clinical attachment loss of the connective fibers, it is known as a periodontal pocket.
Dentists diagnose periodontal disease, in part, with the use of a periodontal probe. This periodontal probe is gently inserted into the gingival sulcus and measures the depth of the sulcus. When a periodontal probe registers a depth of more than 3 millimeters below the gumline, a periodontal pocket may be present. If the attachment at the base of the sulcus has migrated, indicating the degradation of the connective fibers, and the pocket measures more than 3 mm, these factors in combination indicate the presence of a periodontal pocket. When pocket depths surpass 3 mm, it becomes increasingly challenging to clean the pocket with regular home care and professional treatment becomes necessary. When periodontal pockets deepen to reach 6 or 7 mm, however, the traditional clinical cleaning tools used by dentists and dental hygienists can no longer reach deeply enough into the pocket to thoroughly clean away bacteria; thus, periodontal pockets become breeding grounds for the proliferation of new bacteria and the maturation of existing bacteria. When deep periodontal pockets are present, it therefore may become necessary to undergo some type of surgery to thoroughly clean the area and to prevent further bacterial accumulation. If treatment is not performed, or if patients do not maintain their treatment, the teeth are likely to fall out over time.
In order for periodontal pockets to form, a number of interrelated elements must be simultaneously at play. Dental plaque is the most important of these elements. When bacteria that live in dental plaque are allowed to remain on the teeth and under the gumline for a prolonged period, they trigger an inflammatory response, which is a result of the immune system of the host interacting with enzymes and chemicals released by the bacteria. This inflammation gradually causes the destruction of the tissues of the periodontium, which is the set of tissues that surround and support the teeth. When plaque hardens as it accumulates, it calcifies and turns into calculus; calculus cannot be removed by home hygiene methods, and it also creates a sticky, textured surface that encourages the accumulation of even more plaque, which causes further inflammation. This cycle gradually leads to the degradation of periodontal tissue and bone, eventually causing the loss of the teeth. This cycle is also an indication of the importance of proper oral hygiene, which is the most effective way to manage the initial accumulation of bacterial plaque. Early detection and treatment of higher plaque levels can be instrumental in delaying or even halting the destructive processes that are indicated, in their earlier stages, by periodontal pockets.