Plaque smells bad because bacteria in it release sulfur compounds. Brush, floss, and see a dentist for cleaning.
Why
Plaque is a sticky film of bacteria. They release volatile sulfur compounds (hydrogen sulfide, methyl mercaptan) that smell like rotten eggs.
Tartar
Plaque hardens into tartar in 24 to 72 hours.
Fix
- Brush twice a day for 2 minutes.
- Floss daily.
- Clean your tongue.
- Dental cleaning every 6 months.
Disease
Plaque causes cavities and gum disease.
See a dentist
If smell persists.
Bacteria and chemistry
Dental plaque is a biofilm of bacteria in a sticky matrix of polysaccharides and proteins. Anaerobic bacteria in plaque, such as Porphyromonas gingivalis and Fusobacterium nucleatum, break down proteins and produce volatile sulfur compounds like hydrogen sulfide and methyl mercaptan, along with putrescine and cadaverine.
- Plaque begins forming within hours after brushing, and unremoved plaque hardens into tartar (calculus) within 24 to 72 hours.
- Tartar can only be removed by a dental professional.
- Plaque is a main cause of cavities and gingivitis.
Fix
Brush twice a day for 2 minutes with fluoride toothpaste, floss daily, clean the tongue and visit the dentist every 6 months for scaling. Use an interdental brush for wide gaps. If gums are red, bleed or recede, and the smell persists, see a dentist since periodontitis needs treatment. Antimicrobial rinses help short-term. Smoking and dry mouth worsen odor.
Bacteria and chemistry
Dental plaque is a biofilm of bacteria. Bacteria produce volatile sulfur compounds and amines like cadaverine and putrescine that smell bad. Plaque hardens into tartar in 24 to 72 hours.
Fix
Brush, floss, clean the tongue and get cleanings. The CDC notes untreated plaque causes cavities and gum disease.
Chemistry of plaque odor
Dental plaque is a biofilm where bacteria produce hydrogen sulfide, methyl mercaptan, putrescine and cadaverine. Plaque matures in 24 hours into a dense community with anaerobes deep inside. Gum disease pockets of 4 mm or more host anaerobes such as Porphyromonas gingivalis.
Removal and prevention
Brush twice a day for 2 minutes with fluoride toothpaste, floss daily, clean the tongue, and visit a dentist twice yearly. Electric toothbrushes reduce plaque by about 21 percent over manual brushes, according to a Cochrane review. Chlorhexidine rinses are available by prescription for short periods. Tartar can only be removed by a professional.
Based on data from the Cochrane Library and the American Dental Association
