Why do gums bleed during flossing?

From the Guidelines

Gums bleed during flossing primarily due to inflammation caused by bacterial plaque buildup along the gumline, and it is recommended to avoid starting interdental cleaners like floss if not used to it, especially during cancer therapy, as it can break the epithelial barrier and cause bleeding 1. When flossing, it's essential to use a gentle technique to minimize bleeding. According to the guidelines, if you are used to cleaning the area between the teeth, you should consult a dental hygienist/dentist about the most appropriate interdental cleaner, such as floss, toothpick, or brushes 1. Some key points to consider when flossing and brushing teeth:

• Use a soft toothbrush or swab after meals and before sleep to reduce the risk of bleeding 1
• Clean the dentition and gingiva with a mild fluoride-containing, non-foaming toothpaste 1
• Brush teeth twice a day according to the Bass or modified Bass method 1
• If not used to interdental cleaners, do not start with it while on cancer therapy, as it can cause gingival bleeding 1 It's crucial to maintain good oral hygiene to prevent gum bleeding, and if bleeding persists beyond two weeks of proper oral hygiene, it may indicate more serious gum disease and warrants a dental visit.

From the Research

Why Do Gums Bleed with Flossing

• Gums may bleed during flossing due to the presence of inflammation and gingivitis, which can be caused by the accumulation of plaque and bacteria on the teeth and gums 2.
• The use of dental floss can help remove plaque and bacteria from between the teeth and below the gumline, but if the flossing technique is not proper, it can cause damage to the gums and lead to bleeding 3.
• A study found that participants who received instruction on the daily use of an adapted horizontal vertical flossing technique (AHVFT) had significant reductions in interproximal bleeding compared to those who did not receive instructions 3.
• Another study found that flossing can be used as a diagnostic method for proximal gingivitis, and that it can increase the sensitivity and specificity of diagnostic tests for gingivitis 4.
• The presence of certain bacteria, such as Porphyromonas endodontalis, Treponema denticola, and Fretibacterium spp., has been associated with gingival bleeding and inflammation 5.
• Water flossing has been shown to be effective in reducing gingival inflammation and altering the oral microbiota to a more aerobic phenotype, which can help reduce oral malodor and promote oral health 6.

Factors Contributing to Bleeding Gums

• Poor oral hygiene habits, such as infrequent brushing and flossing, can contribute to the accumulation of plaque and bacteria on the teeth and gums, leading to inflammation and bleeding 2, 5.
• The use of improper flossing technique can cause damage to the gums and lead to bleeding 3.
• The presence of certain bacteria, such as Porphyromonas spp., Treponema spp., and Bacteroides spp., has been associated with gingival bleeding and inflammation 5.
• Flossing and rinsing with mouthwash twice daily can be associated with higher total abundance of bacteria in the Proteobacteria phylum, but with lower bacterial diversity compared to those who never floss or never use mouthwash 5.