When a dental professional calls out a series of numbers during an examination, they are performing dental probing, also known as periodontal charting. This routine procedure is a quick, non-invasive way to assess the health of your gums and the underlying bone structure. It is designed to detect and monitor the earliest signs of gum disease, which often go unnoticed by the patient. Tracking these measurements over time helps the dental team identify changes before they lead to significant issues.
The Procedure and Tools Used
The primary goal of the procedure is to measure the depth of the gingival sulcus, the small space between the tooth surface and the surrounding gum tissue. When inflammation or disease is present, this space deepens and becomes a periodontal pocket. The measurement is taken using a specialized instrument called a periodontal probe, a thin, calibrated metal tool marked in millimeters.
The dental professional gently inserts the blunted tip of the probe into the pocket until it reaches the point where the gum tissue is firmly attached to the tooth root. Measurements are typically taken at six distinct points around every tooth. A consistent, light pressure of about 25 grams is applied to ensure accuracy.
If the gums are healthy, the patient should feel minimal sensation during probing. If the gums are inflamed due to bacterial buildup, the tissue may feel sensitive and might bleed slightly upon contact. This bleeding on probing (BOP) is recorded alongside the depth measurements and is a sign of active inflammation.
Interpreting the Pocket Depth Measurements
The numbers called out during probing correspond directly to the measured depth in millimeters (mm) and serve as a diagnostic map of gum health. Shallow readings signify a healthy environment where the gum is tightly secured to the tooth. A measurement between one and three millimeters with no bleeding is the standard for healthy gum tissue.
When a measurement reaches four or five millimeters, it suggests the gum tissue has started to detach from the tooth root, indicating gingivitis or early periodontitis. These deeper pockets allow bacteria and hardened plaque (calculus) to accumulate beyond the reach of home cleaning tools. Bleeding along with a four or five-millimeter reading confirms active inflammation and an early stage of gum disease.
Measurements of six millimeters or greater signal moderate to advanced periodontitis. At this depth, significant bone loss has likely occurred, threatening the tooth’s stability. These high numbers require immediate and often intensive intervention to halt the disease progression.
Follow-Up Care Based on Results
The treatment plan following periodontal charting is determined by the measured pocket depths and the presence of bleeding. If readings are within the healthy one to three-millimeter range with no bleeding, the recommendation is to maintain your current home care routine and schedule regular professional cleanings, typically every six months.
For measurements in the four to five-millimeter range, the dental professional may recommend scaling and root planing, often called a “deep cleaning.” This procedure involves removing plaque and tartar deposits from below the gumline and smoothing the root surfaces to encourage reattachment and reduce pocket depth. Patients with these measurements are often placed on a more frequent cleaning schedule, such as every three or four months.
If multiple sites show depths of six millimeters or more, or if pockets do not improve after initial treatment, a referral to a periodontist may be necessary. The periodontist can evaluate the need for advanced treatments, including surgical procedures to reduce pocket depth, regenerate lost bone, or correct gum recession. The goal of all follow-up care is to stabilize the health of the supporting tissues.