Damage occurring at the gumline, known as the cervical area, is common and successfully treated. This damage can be true bacterial decay or non-decay-related wear, but restoration is usually straightforward. Treatment success depends on correctly identifying the specific type and cause of the lesion.
Understanding Lesions at the Gumline
The term “gumline cavity” encompasses two distinct types of structural loss: true tooth decay and non-carious cervical lesions (NCCLs). True decay, or cervical caries, is caused by plaque bacteria producing acid that demineralizes the tooth structure near the gum. Decay progresses rapidly because the exposed tooth root is covered by cementum, which is softer than enamel. Cementum is less mineralized, making it approximately twice as susceptible to acid attack.
Non-carious cervical lesions are physical or chemical defects not caused by bacteria. Abrasion appears as a flat, smooth loss of tooth structure, typically resulting from aggressive or horizontal toothbrushing with a hard-bristled brush. Erosion involves the chemical dissolution of tooth structure due to non-bacterial acid sources, often appearing broad and shallow. Abfraction is a unique, wedge-shaped notch caused by excessive forces, such as clenching or grinding. These forces create flexural stress at the neck of the tooth, causing microscopic fragments to chip away.
These lesions often occur simultaneously, creating a complex defect that exposes the sensitive dentin layer. Exposed dentin deepens quickly, leading to increased sensitivity to temperature changes. Distinguishing between causes is important because treatment must address both the existing damage and the underlying cause to prevent recurrence.
Treatment Methods for Gumline Damage
Filling is an effective treatment, though the approach varies based on the lesion type, size, and depth. For small lesions or minimal sensitivity, non-filling treatments like fluoride varnish or desensitizing agents may be used to encourage remineralization. If the lesion is caused by non-carious wear, restorative bonding is often the primary treatment to rebuild lost tooth structure.
The choice of restorative material is important due to the high biomechanical stress in the cervical area. Composite resin is frequently used for aesthetics but is relatively stiff. Glass Ionomer Cement (GIC) or Resin-Modified GIC (RMGIC) are favored alternatives because their modulus of elasticity is closer to natural dentin. This flexibility allows the filling to better withstand flexing forces without detaching or fracturing.
RMGIC also offers the advantage of releasing fluoride, which helps protect the remaining tooth structure from secondary decay. The procedure can be technically demanding due to the proximity to gum tissue, making moisture control difficult. Bonding to dentin and cementum is more challenging than bonding to enamel, requiring specific adhesive techniques to ensure the restoration remains sealed.
Specific Causes and Long-Term Prevention
Preventing gumline damage requires managing the mechanical and chemical factors causing structure loss. For abrasion, prevention centers on adopting a gentle technique. The Modified Bass Technique is recommended, involving a soft-bristled toothbrush angled at 45 degrees toward the gumline, using small, circular, or vibrating motions instead of horizontal scrubbing.
Managing the forces that lead to abfraction lesions is accomplished by addressing habits like clenching or grinding (bruxism). A custom-fitted night guard absorbs excessive forces, preventing harmful flexing of the tooth structure. For individuals with a misaligned bite, orthodontic treatment may be recommended to redistribute biting forces more evenly.
To mitigate erosion caused by acid, dietary and behavioral adjustments are necessary, especially concerning low pH beverages like sodas, sports drinks, and citrus juices. If acidic items are consumed, rinse the mouth with plain water immediately afterward to neutralize the acid. Brushing should be delayed for at least 30 minutes, as the enamel is temporarily softened and susceptible to abrasive wear.