A dental filling is a restorative material used to repair a tooth damaged by decay or fracture, restoring its shape, function, and integrity. Fillings are designed to withstand chewing forces, but they are not permanent. Their longevity depends heavily on consistent maintenance and care. By understanding the common reasons for filling failure and adopting preventative measures, you can maximize the lifespan of your restoration and protect your oral health.
Understanding Why Fillings Fail
Fillings fail for three main reasons: secondary decay, material degradation, and mechanical trauma. Secondary decay (recurrent decay) is new tooth decay that forms around the edges of an existing filling. Bacteria and acid penetrate the microscopic gap between the filling and the tooth structure, dissolving the material beneath the restoration and causing the filling to loosen.
Material degradation involves the breakdown of the filling material or the adhesive bond over time. Composite resin fillings, for example, can experience wear and hydrolysis, weakening the bond due to the constant presence of water and enzymes in the mouth. This degradation is a natural process accelerated by the oral environment.
The third cause is trauma or stress, often resulting in a fracture of the filling or the surrounding tooth. This occurs from biting down on something hard or from chronic, excessive forces like teeth grinding. Fillings can chip, crack, or dislodge when subjected to intense mechanical stress.
Daily Oral Hygiene and Dietary Adjustments
The longevity of a filling is significantly impacted by consistent daily oral hygiene, especially focusing on the restoration’s margins. When brushing, use a soft-bristled toothbrush and fluoride toothpaste, paying deliberate attention to the area where the filling meets the tooth enamel. This precise cleaning prevents plaque accumulation, which is the primary cause of secondary decay.
Flossing is important to remove food particles and bacteria from between teeth and along the filling’s contact points. Gently slide the floss into the interdental space to clean the sides of the filled tooth without snapping it down, which could jar a loose restoration. Using a fluoride mouthwash provides an additional layer of protection by strengthening the enamel surrounding the filling.
Dietary habits also play a large role in a filling’s lifespan. Minimize highly acidic foods and drinks, such as citrus fruits, vinegars, and sodas, which can erode the enamel and the bonding material. Frequent sugar exposure feeds bacteria that produce damaging acid, increasing the risk of recurrent decay.
Avoid rapid temperature extremes, such as drinking hot coffee immediately after chewing ice, as the expansion and contraction stress the filling and the tooth. Additionally, extremely hard or sticky foods, such as hard candies, nuts, and caramels, can crack the filling material or physically tug the restoration out of the cavity.
Managing Physical Stressors (Bruxism and Habits)
Excessive physical force, particularly from bruxism, threatens the integrity of dental restorations. Bruxism involves unconsciously grinding or clenching the teeth, often during sleep, subjecting fillings to immense, sustained pressure. This cyclic loading can lead to micro-fractures in the filling material or the surrounding tooth structure.
If you experience signs of clenching or grinding, such as jaw pain or flattened teeth, a custom-fitted nightguard is recommended. This device creates a protective barrier, evenly distributing the forces generated by bruxism across the arch instead of concentrating them on individual teeth. A custom guard provides superior protection compared to over-the-counter boil-and-bite options.
Destructive oral habits must also be avoided to protect fillings. Chewing on non-food items like ice cubes, pen caps, or fingernails concentrates force on small areas of the tooth, which can fracture a filling or chip the enamel margin. Using teeth to tear tape or open packages introduces lateral forces that can leverage a restoration out of the tooth.
Immediate Action If a Filling Feels Loose
If you feel a filling shift or notice a sudden rough spot, contact your dentist immediately for an appointment. The exposed inner part of the tooth is vulnerable to decay and sensitivity, and a swift repair prevents further damage. While waiting, you can take temporary steps to protect the area.
To guard the exposed cavity, use over-the-counter temporary filling material or dental wax, both available at most pharmacies. Follow the product instructions to place the material into the cavity, creating a seal that protects against debris and temperature sensitivity. A small piece of sugar-free gum can also be pressed into the space as a temporary measure.
Avoid chewing food on the side of the mouth with the affected tooth to prevent further breakage or dislodging the remaining material. Stick to a diet of soft foods and rinse your mouth gently with warm salt water to keep the area clean and minimize irritation. These actions are temporary and do not replace professional dental care.