A dental crown is a cap placed over a damaged tooth, restoring its shape, size, strength, and appearance. When patients notice their gum tissue changing around this restoration, they often wonder if the gums are physically “growing” around the crown. This observation points to a real biological process, which can range from a common inflammatory reaction to a true overgrowth of tissue. The gum tissue’s response depends on the restoration’s fit and the patient’s oral hygiene.
Gum Tissue Response to Crowns
What appears to be the gums “growing” over the crown is most frequently an inflammatory response known as gingivitis, which causes the tissue to swell. This swelling is the body’s reaction to bacterial plaque accumulation at the crown’s edge, making the gum line look puffy and enlarged. The swollen tissue expands outward, often covering a portion of the crown, and results in redness and bleeding upon brushing.
True gum growth, medically termed gingival hyperplasia, is a less common but more significant reaction involving an actual increase in the number or size of the gum cells. While chronic irritation from a restoration can sometimes trigger this condition, the apparent “growth” is usually volume increase from fluid retention and inflammation, not true cellular proliferation. The resulting puffy tissue traps more plaque, perpetuating the cycle of irritation and swelling.
Identifying the Source of Irritation
The primary source of irritation is often an issue with the crown’s fit, particularly at the margin, the line where the crown meets the tooth structure. A margin that is poorly contoured, rough, or misaligned creates a ledge where plaque and bacteria easily collect and hide from a toothbrush. The presence of these bacterial toxins directly initiates the inflammatory cascade in the surrounding gum tissue. Margins placed below the gumline (subgingivally) are more likely to cause bleeding than those placed above the gumline (supragingivally).
A more complex technical issue is the violation of the biological width, the required minimum space (approximately 2 millimeters) between the crown margin and the underlying bone. This space consists of the connective tissue attachment and the junctional epithelium. If the crown invades this attachment space, the body reacts defensively by creating chronic inflammation, bleeding, and localized gum enlargement. The body attempts to re-establish the necessary space, often leading to persistent gingivitis or even bone loss. Rarely, the gum tissue may react to the crown material itself or the cement used for placement.
Correcting Gum Issues Related to Crowns
The treatment for gum issues around a crown depends entirely on accurately identifying the underlying cause of the irritation. If the inflammation is solely due to plaque accumulation, the issue can often be resolved through professional deep cleaning (scaling) combined with improved at-home oral hygiene practices. The dental professional will educate the patient on proper brushing and flossing techniques specifically around the crown margin to remove bacterial irritants.
When the cause is an ill-fitting or rough crown margin, the restoration must be adjusted, polished, or replaced entirely to ensure a smooth, precise seal against the tooth. Replacing the crown removes the physical irritant and the plaque trap, allowing the inflamed gum tissue to return to its healthy state.
If the biological width has been violated, the solution often requires a minor surgical procedure called crown lengthening before a new crown is made. This procedure involves reshaping the gum and sometimes the bone to re-establish the necessary space, ensuring the new crown margin respects the biological width.
For cases of true gingival hyperplasia—excessive gum tissue growth—a gingivectomy may be necessary. This minor surgery removes the overgrown gum tissue, often using a scalpel or laser, to restore a normal contour to the gum line. Correcting the underlying problem is paramount to long-term success, as simply trimming the tissue without addressing the source of irritation will only result in the issue recurring.