Flossing is a necessary part of maintaining oral hygiene, designed to remove plaque and food debris from between teeth and beneath the gumline. Many people worry whether this routine can cause an infection. In a generally healthy mouth, flossing does not cause infection; rather, it prevents infections caused by bacterial buildup. The risk of infection is tied to pre-existing conditions or physical trauma that allows bacteria to enter the bloodstream.
Understanding the Risk of Infection
The primary risk associated with flossing is the temporary introduction of oral bacteria into the bloodstream, known as transient bacteremia. This occurs when the physical disruption of the gum tissue, especially if inflamed, allows bacteria to pass into the small blood vessels of the gums. Studies show that flossing can cause bacteremia in both healthy and diseased individuals at a comparable rate to certain dental treatments.
For most healthy people, this temporary presence of bacteria is harmless because the immune system quickly eliminates the microbes. However, the risk changes for individuals with specific health concerns. Patients with certain heart conditions, such as prosthetic heart valves or a history of infective endocarditis, face a more serious risk from bacteremia. Flossing should also be avoided immediately following oral surgery, such as a tooth extraction, for 24 to 48 hours to allow the surgical site to stabilize.
Bleeding Gums and Pre-existing Conditions
Bleeding during flossing is often mistaken as a sign of causing an infection, but it signals an existing problem. When plaque, a sticky film of bacteria, is not removed, it irritates the gum tissue along the gumline. This irritation leads to gingivitis, the mildest form of gum disease, causing the gums to become inflamed, red, and swollen.
These inflamed tissues are tender and prone to bleeding upon disturbance, such as flossing. The bleeding is the inflamed tissue reacting to the mechanical removal of the bacterial plaque that caused the inflammation. Therefore, bleeding indicates that flossing is necessary to treat the condition by removing the source of the irritation.
If gingivitis is left untreated, it can progress to periodontitis, a more severe disease where infection spreads below the gumline and damages the bone supporting the teeth. Consistent flossing is necessary to prevent gingivitis and manage periodontitis. Bleeding is not a signal to stop flossing, but a sign that the gums need consistent, gentle cleaning to reverse the inflammation and restore tissue health.
Preventing Trauma Through Correct Technique
The only risk of local injury and subsequent infection from flossing comes from an improper or overly aggressive technique. Flossing should be a gentle, controlled motion that cleans the tooth surface without damaging the gum tissue. Using the correct method minimizes trauma and maximizes plaque removal.
To floss correctly, use about 18 inches of floss, winding most of it around the middle fingers and leaving a small section to work with. Hold the floss tautly between the thumbs and index fingers, then gently slide it between the teeth. The floss must be curved into a “C” shape around the tooth at the gumline and gently rubbed up and down the side of the tooth.
Avoid snapping or forcing the floss into the gums, which can cause cuts or bruising. For each tooth, use a new, clean section of the floss to avoid transferring bacteria and debris throughout the mouth. Alternative tools, such as water flossers or interdental picks, are effective options for individuals who struggle with traditional string floss.