The uncomfortable feeling that your back teeth are shifting or “floating” is a serious sensation of pathological tooth mobility. While all teeth have a slight, barely perceptible movement, this feeling indicates movement that has exceeded normal limits. This abnormal looseness means the structures supporting the tooth within the jawbone are compromised, requiring immediate professional dental attention. The feeling is often more pronounced with back teeth due to the intense forces they manage during chewing.
Understanding Tooth Mobility
The most frequent cause of teeth mobility, particularly in back teeth, is the progression of chronic gum disease, known as periodontitis. This condition is an infection that causes inflammation, leading to the gradual destruction of the periodontal ligament fibers and the surrounding alveolar bone. These structures anchor the tooth firmly into its socket, and their loss creates the physical instability perceived as a floating tooth.
As periodontitis advances, the body’s inflammatory response results in the resorption of the jawbone, reducing the height of the tooth’s support. When the bone level drops significantly, the tooth root loses its rigid foundation and begins to move excessively in the socket, causing the “floating” feeling. The degree of mobility is inversely related to the amount of supporting bone remaining around the root.
Non-Disease Related Instability
Not all tooth instability is caused by long-term periodontitis; acute issues can also cause a sudden feeling of looseness. A localized dental abscess, originating from a severe infection at the root tip, can cause rapid and temporary bone loss in the immediate area. This localized destruction of the supporting bone quickly leads to increased tooth movement until the infection is resolved.
Excessive mechanical stress, known as occlusal trauma, is another common factor, often stemming from habits like bruxism, or chronic clenching and grinding. The strong, repetitive forces stress the periodontal ligament, causing it to widen as an adaptive response. This widening creates a cushioning effect that allows the tooth to move more than usual, contributing to the mobile sensation.
Diagnosis and Management
Diagnosis
A dental professional will begin by assessing the degree of mobility, often using a standardized grading system to measure movement in both horizontal and vertical directions. Diagnostic X-rays are used to visualize the root structure and determine the level of the supporting alveolar bone. A periodontal probe is also used to measure the depth of the gum pockets around the tooth, which helps gauge the extent of attachment loss.
Management
Management focuses on eliminating the cause of the instability and stabilizing the tooth. If periodontitis is diagnosed, treatment begins with deep cleaning procedures, known as scaling and root planing, to remove the bacterial deposits causing inflammation. For severe mobility, a dentist may temporarily or permanently stabilize the tooth by bonding it to an adjacent, firmer tooth in a process called splinting. This stabilization allows the surrounding tissues to heal.