A healthy mouth relies on the periodontium, the supporting structures around the teeth. These tissues include the gingiva (gum tissue), the periodontal ligament, and the alveolar bone that anchors the tooth root. In a healthy state, the gum tissue fits snugly around the tooth, forming a shallow groove called the gingival sulcus, typically measuring between one and three millimeters deep. A periodontal pocket is an abnormal deepening of this space, created when the gum tissue detaches from the tooth surface, signaling the breakdown of supporting structures.
How Periodontal Pockets Form
The process begins with the accumulation of bacterial plaque, a sticky film that constantly forms on the teeth and around the gum line. If this plaque is not removed through daily brushing and flossing, it can harden into a rough deposit called calculus, or tartar. The bacteria within this plaque and calculus release toxins that irritate the gingiva, triggering an inflammatory response known as gingivitis. The gums become red, swollen, and may bleed easily during oral hygiene.
Inflammation causes the gum tissue to swell and pull away from the tooth, deepening the sulcus and creating an environment for more bacteria to thrive. Once the inflammation progresses beyond the gum tissue to affect the underlying bone and connective fibers, the condition is diagnosed as periodontitis. Bacteria and their toxins destroy the periodontal ligament and alveolar bone. As attachment fibers and bone are lost, the space deepens further, becoming a true periodontal pocket.
Periodontal pockets are classified based on their relationship to the alveolar bone. A suprabony pocket is located above the level of the existing bone, while an infrabony pocket extends into the bone, lying below the bone level. This deepening space provides an ideal environment for harmful bacterial colonies to multiply, leading to an accelerating cycle of tissue destruction and bone loss. This progressive damage can ultimately result in tooth mobility and eventual tooth loss.
Understanding Pocket Measurement
Dental professionals use a periodontal probe to assess gum tissue health. This thin instrument has millimetre markings and is gently inserted into the space between the gum and the tooth. The measurement recorded is the probing depth, which is the distance from the gum margin to the base of the pocket.
A healthy probing depth is between one and three millimeters, indicating a well-attached gingival sulcus. A measurement of four millimeters or greater suggests a pathological pocket and the beginning of periodontal disease. Pockets measuring five to six millimeters indicate moderate disease, while depths of seven millimeters or more characterize advanced periodontitis. This measurement process, known as periodontal charting, is performed systematically around six sites on every tooth.
Pocket depth measurement is used with the position of the gum margin to determine Clinical Attachment Loss (CAL). CAL is a more accurate indicator of disease severity because it accounts for both pocket depth and any gum recession that may have occurred. Monitoring these measurements over time allows the dental team to track disease progression and evaluate treatment effectiveness.
Addressing and Treating Periodontal Pockets
The primary goal of treating periodontal pockets is to reduce their depth by eliminating the bacteria and calculus that fuel the disease process. For early to moderate cases, typically with pockets up to five millimeters, Scaling and Root Planing (SRP) is the first line of non-surgical treatment. Often referred to as a deep cleaning, SRP involves using specialized instruments to remove plaque and hardened calculus from tooth surfaces both above and below the gum line.
Scaling and Root Planing (SRP)
The scaling portion focuses on removing deposits, while root planing involves smoothing the tooth root surfaces. Smoother roots discourage bacterial colonization and encourage the gum tissue to reattach more firmly to the tooth. Local anesthesia is often used for comfort during this thorough procedure, which may require multiple appointments depending on the extent of the disease. Following this deep cleaning, the dental team re-evaluates pocket depths after four to six weeks to confirm the healing response.
Surgical Intervention
When non-surgical methods do not sufficiently reduce pocket depths, especially in cases of six millimeters or more, surgical intervention may be required. Pocket reduction surgery involves the periodontist gently lifting the gum tissue to gain direct access to the deeper root surfaces and underlying bone. This allows for the complete removal of disease-causing bacteria and calculus. The surgeon may smooth damaged bone surfaces to reduce spaces where bacteria can hide. Bone grafting or guided tissue regeneration procedures may also be utilized to encourage the regrowth of lost bone and tissue, helping to secure the tooth and reduce the pocket depth long-term.