The gum tissue that fills the space between your teeth is called the interdental papilla, and if it looks swollen, puffy, or like it’s growing larger than normal, the most common reason is inflammation from plaque buildup. But several other causes, from medications to hormonal shifts, can make this tissue enlarge noticeably. Understanding what’s behind it helps you figure out whether better brushing will fix it or whether you need professional care.
What That Gum Tissue Actually Is
The small, triangular points of gum tissue that sit between each pair of teeth are the interdental papillae. They serve a specific purpose: they seal the gaps between your teeth, protecting the underlying bone and preventing food from packing into those spaces. When healthy, they’re firm, pale pink, and fit snugly into the space without bulging or bleeding.
When something irritates or inflames this tissue, it swells. Because the papillae are wedged into tight spaces, even minor swelling becomes visible quickly. You might notice the gum looks rounder, darker pink or red, or seems to have “grown” up between two teeth. In some cases, the tissue can enlarge so much it partially covers the teeth themselves.
Plaque Buildup Is the Most Common Cause
Plaque is a sticky, colorless film of bacteria that forms on your teeth after eating, especially after sugars and starches. When it isn’t removed daily, it hardens into tartar (calcite deposits) below and along the gumline. Tartar creates a protective shield for bacteria and directly irritates the gum tissue. The longer plaque and tartar sit against your gums, the more inflamed and swollen the tissue becomes. This is gingivitis, and the interdental papillae are often the first place it shows up because plaque accumulates heavily in those hard-to-reach spaces between teeth.
The swelling typically starts as a slight ballooning of the papilla, then gradually worsens. You’ll likely notice bleeding when you brush or floss, tenderness, and gums that look red rather than pink. At this stage, the condition is reversible with consistent cleaning. Left alone, the inflammation can progress into periodontitis, where the supporting bone around the teeth starts to break down.
Medications That Cause Gum Overgrowth
Certain prescription drugs are well known for causing the gum tissue between teeth to enlarge, sometimes dramatically. The three main drug classes responsible are anticonvulsants (seizure medications), immunosuppressants (used after organ transplants), and calcium channel blockers (used for high blood pressure and heart conditions).
Phenytoin, a seizure medication, has the highest prevalence of gum overgrowth among all drugs. Cyclosporine, prescribed to prevent organ rejection after transplants, causes visible gum enlargement in roughly 53% of patients taking it after kidney transplants. Among blood pressure medications, nifedipine and amlodipine are the most frequently linked to this problem.
Drug-related gum overgrowth typically starts as bead-like swelling of the interdental papillae, then gradually spreads to the gum margin along the teeth. The tissue may become so enlarged that it creates false “pockets” around the teeth where bacteria collect, compounding the problem. If you take any of these medications and notice your gums growing between your teeth, your doctor may be able to switch you to an alternative drug. The overgrowth often improves once the medication changes, though surgical removal of excess tissue is sometimes needed.
Hormonal Changes During Pregnancy and Puberty
Hormonal shifts can make the gum tissue between your teeth visibly puffy even if your oral hygiene hasn’t changed. During pregnancy, levels of estrogen and progesterone rise to 30 and 10 times their normal levels, respectively, by the third trimester. These hormones affect gum tissue in several ways: they increase blood flow to the gums, alter the immune response in the tissue, and actually serve as a growth factor for certain bacteria in the mouth, helping them multiply faster.
The result is that gums become less efficient at fighting off the inflammation caused by normal amounts of plaque. The swelling tends to be most prominent between the teeth rather than on the front or back surfaces of the gums. Puberty produces a similar effect on a smaller scale. In both cases, the enlargement generally improves after hormone levels normalize, but meticulous cleaning during these periods prevents the inflammation from doing lasting damage.
Reactive Growths Between Teeth
Sometimes a localized lump or mass appears between two specific teeth rather than a general puffiness across all of them. Several types of reactive growths can cause this. A pyogenic granuloma is a red, rapidly growing mass that typically appears within a few weeks, often triggered by an irritant like a rough filling edge, a broken tooth, or orthodontic brackets. It can grow through the space between teeth and appear on both sides. Despite the alarming speed, these growths are not cancerous.
A fibrous growth (peripheral fibroma) presents differently: firm, pink, and slow-growing, typically rising from below the gumline or from the papilla itself. It’s also benign. In both cases, the source of irritation, whether it’s plaque, a jagged restoration, or a poorly fitting dental appliance, needs to be identified and addressed. The growth itself is usually removed with a minor surgical procedure.
Vitamin C Deficiency
Severely low vitamin C levels cause a condition called scurvy, and one of its hallmark signs is swollen, bleeding gums, specifically the interdental papillae. Vitamin C is essential for maintaining the tiny blood vessels in gum tissue. Without enough of it, those vessels break down, leading to inflammation, hemorrhaging, and spongy-looking gums between the teeth. This is uncommon in developed countries but can occur in people with very restricted diets or certain absorption issues.
Signs That Need Prompt Attention
Most interdental gum swelling is mild gingivitis that responds to better cleaning. But certain symptoms signal something more serious. Acute necrotizing ulcerative gingivitis is a painful infection characterized by sudden onset of mouth pain, spontaneous bleeding, and a very specific appearance: the tips of the papillae look “punched out,” with crater-like ulcers replacing the normal pointed gum tissue. There’s often a grayish film over the damaged areas and noticeable bad breath. This condition destroys tissue rapidly and can spread to deeper structures if not treated quickly.
On the other end of the timeline, gum overgrowth that goes ignored for months or years can lead to deep pockets around the teeth, bone loss, tooth loosening, and pathological shifting of teeth out of alignment. In extreme cases documented in the medical literature, untreated drug-induced gum enlargement has resulted in loss of entire sets of teeth because the supporting structures couldn’t be salvaged.
How Swollen Interdental Gums Are Treated
For plaque-related swelling, the first step is always thorough cleaning. A dental professional will remove tartar above and below the gumline, then reinforce home care techniques. At home, the focus is on consistent daily cleaning between the teeth using floss or interdental brushes. When gums are already swollen, a soft-bristled brush and an antiseptic mouth rinse containing chlorhexidine can help control bacteria while the tissue heals.
If the enlargement is significant and doesn’t resolve with cleaning alone, a procedure called gingivectomy removes the excess tissue. This restores the normal shape of the gums, eliminates the false pockets where bacteria hide, and makes future cleaning easier. After the procedure, a protective dressing covers the area for about a week. Full healing typically takes around two months. The key challenge with gum overgrowth is recurrence: without consistent home care and management of any underlying cause (switching a medication, maintaining good hygiene during pregnancy), the tissue tends to enlarge again.
Keeping the Tissue Healthy Long Term
The interdental papillae are the most neglected part of most people’s oral hygiene routine because they sit in spots that a toothbrush alone can’t reach. Daily flossing or use of small interdental brushes is the single most effective way to prevent plaque-driven swelling. If you wear braces, have dental restorations, or take medications linked to gum overgrowth, you’re at higher risk and need to be especially consistent. Regular professional cleanings remove tartar that home care can’t address, keeping the cycle of buildup and inflammation from gaining a foothold.