Yes, chewing gum can pull out a dental filling, but it is rarely the sole cause of failure. A sticky substance like gum acts as a trigger, applying a strong, concentrated force that exploits an existing weakness in the restoration. A perfectly healthy and well-bonded filling is highly resistant to being dislodged by the forces generated by chewing gum. This interaction is better understood by looking at the science of how materials stick together.
Understanding Adhesion and Cohesion
The potential for chewing gum to dislodge a filling depends on the interplay between two physical forces: adhesion and cohesion. Adhesion is the force of attraction between two different materials, specifically the bond holding the dental filling material to the tooth structure. Cohesion is the internal strength of a single material, applying to both the gum’s stickiness and the internal strength of the filling.
When you chew gum, its highly cohesive, sticky mass presses against the filling. As you open your mouth, the gum attempts to pull away, translating its internal cohesive strength into an outward force on the restoration. For a filling to be successfully pulled out, this cohesive force from the gum must overcome the adhesive bond between the filling and the tooth.
Older filling types, such as silver amalgam, typically rely on mechanical retention rather than forming a chemical bond. Modern composite resin fillings use chemical bonding to create a strong adhesive seal. Both types can be susceptible if the seal is compromised, as the gum’s sticky pull most effectively exploits these weak spots, especially when the adhesive bond has degraded over time.
The Condition of the Filling Matters Most
Chewing gum is usually the final event that dislodges a filling, not the primary reason for its failure. The filling must already be compromised for the cohesive force of the gum to be effective. The most common factor weakening a filling is recurrent decay, which is new bacterial decay that forms underneath or around the edges of the existing restoration.
This decay creates tiny gaps, known as microleakage, between the filling and the tooth, allowing bacteria and food particles to seep in. As the decay progresses, it eats away at the underlying tooth structure that supports the filling, destroying the adhesive or mechanical bond. Once this support is gone, the filling becomes a loose plug, making it highly vulnerable to being lifted out by a sticky substance.
Other factors also contribute to the weakening of the dental restoration over time. Constant wear and tear from daily chewing, grinding, or clenching can cause the filling material to fatigue, crack, or wear down. Older amalgam fillings can also expand and contract slightly with temperature changes, which may eventually weaken the surrounding tooth structure. A filling that was improperly placed or poorly fitted can also have a weaker initial seal, setting it up for premature failure when subjected to the pulling force of gum.
What To Do If a Filling Comes Loose
If a filling comes loose, the first and most important step is to contact your dentist immediately for an urgent appointment. While you wait for professional care, there are temporary measures you should take to protect the exposed tooth. If you can retrieve the filling, keep it safe, as the dentist may want to inspect it to determine the cause of the failure.
Gently rinse your mouth with warm water, or a warm salt-water solution, to clean the area and remove any debris. This helps to keep the vulnerable area clean until you can be seen by a professional. You should avoid chewing food on the side of your mouth where the filling is missing to prevent further damage to the exposed tooth.
To reduce sensitivity and protect the cavity, you can apply a temporary covering. Over-the-counter temporary dental cement or dental wax, available at most pharmacies, can be pressed gently into the void. Never attempt to re-glue the filling with household adhesives, and only use products specifically designed for temporary dental care.