Most dental myths come from something that sounds sensible: scrub harder, skip floss if the research is weak, wait until something hurts. The evidence points the other way. Gentle brushing with fluoride toothpaste twice a day, cleaning between your teeth once a day, limiting how often you snack on sugar and starch, and regular checkups still do most of the work. Here are ten common myths and what the evidence says.
1. Does brushing harder clean better?
No. Plaque is soft and comes off with gentle pressure. Scrubbing hard, especially with a firm brush, can wear the gums back and abrade the exposed root surface, which can lead to sensitivity. The ADA recommends a soft-bristled brush held at a 45-degree angle to the gums, using short, gentle strokes. [1] Our post on brushing too hard explains the warning signs.
2. Is flossing no longer necessary?
Flossing still matters, but the evidence is more modest than many people assume. In 2016, news reports pointed out that the 2015-2020 Dietary Guidelines for Americans no longer mentioned flossing. The reason was procedural. The guidelines focus on diet, and their advisory committees hadn't reviewed evidence on brushing or flossing, so the advice wasn't carried forward. The Department of Health and Human Services then told the ADA that cleaning between teeth is an important oral hygiene practice. [3]
The most thorough summary of the research is a 2019 Cochrane review of 35 trials. It found that flossing in addition to brushing may reduce gum inflammation more than brushing alone, and that interdental brushes may work better than floss. The evidence was low certainty, the trials were short, and none measured cavities between teeth. [2] That is a reason to choose a method you'll actually use, not a reason to skip it. The ADA still recommends cleaning between your teeth every day, with floss, interdental brushes, water flossers or other cleaners. [4]
3. Is chewing sugar-free gum as good as brushing?
No. Chewing sugar-free gum for about 20 minutes after a meal increases saliva, which helps neutralize acid and wash away food, and the ADA says it can help prevent decay. [5] But it doesn't remove plaque from the tooth surfaces or between teeth. It's a helpful extra, not a replacement.
4. If my gums bleed when I floss, should I leave them alone?
No. Bleeding usually means the gums are inflamed from plaque left along the gumline and between teeth. [6] Gentle daily cleaning in those spots usually lets the inflammation settle, and the bleeding eases with it. If it doesn't improve after a couple of weeks, or you take a blood thinner, have it checked, because bleeding can have other causes.
5. If I brush well the week before my appointment, will my dentist know?
Usually, yes. Hardened tartar can't be brushed off, and gum inflammation from months of plaque doesn't settle in a few days. That isn't a reason to feel judged. It just means the checkup reflects your everyday routine, which is what we want to see.
6. Is sugar the only cause of cavities?
No. Bacteria in plaque make acid from both sugars and starches. [7] Crackers, chips and bread that cling to teeth can feed bacteria for a long time. How often you snack matters as much as what you eat, because each snack starts a new acid attack.
7. Do sensitive teeth always mean worn enamel?
No. Sensitivity happens when dentin is exposed, and worn enamel is only one way that happens. Gum recession, decay, a cracked tooth, a worn filling and recent whitening can all cause it. [8] A 2013 study of 787 adults in general dental practices found sensitivity was more common in people with gum recession and in people who had whitened at home. [9] Our post on the causes of tooth sensitivity goes through them, and foods to avoid with sensitive teeth covers the common triggers.
8. Is gum disease only a problem for my mouth?
Not entirely. Gum disease and diabetes affect each other. Diabetes raises the risk of gum disease, and gum disease can make blood sugar harder to control. [6] Researchers have also found associations between gum disease and heart disease, rheumatoid arthritis and other conditions, but an association doesn't prove that one causes the other. Treating gum disease is worth doing for your mouth alone.
9. Are whiter teeth healthier teeth?
Not necessarily. Tooth color varies naturally and darkens with age, coffee, tea, red wine and some medications, none of which means a tooth is unhealthy. A bright white tooth can still have decay or gum disease around it. Smoking and some dental problems do change tooth color, so a tooth that darkens on its own should be checked. If you want a lighter shade, our teeth whitening page explains the options.
10. If nothing hurts, do I still need a checkup?
Yes. Early cavities and gum disease usually cause no pain. By the time a tooth hurts, the problem is often bigger and the treatment more involved. Our post on cavity pain explains how decay progresses before it hurts.
Where can I ask about my own routine in Jacksonville?
Bring your questions, and your toothbrush if you like, to your next visit. A comprehensive dental examination shows how your routine is working. Call our office at 904-398-1549 or contact us.
Sources
American Dental Association, MouthHealthy. Brushing your teeth. Accessed October 6, 2026.
Worthington HV, MacDonald L, Poklepovic Pericic T, et al. Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries. Cochrane Database Syst Rev. 2019;4(4):CD012018. doi:10.1002/14651858.CD012018.pub2 (retrieved via PubMed)
ADA News. National media focus on floss; government confirms importance. August 8, 2016.
American Dental Association. Home oral care. Accessed October 6, 2026.
American Dental Association, MouthHealthy. Chewing gum. Accessed October 6, 2026.
National Institute of Dental and Craniofacial Research. Periodontal (gum) disease. Last reviewed August 2026.
National Institute of Dental and Craniofacial Research. Tooth decay. Last reviewed September 2025.
American Dental Association, MouthHealthy. Sensitive teeth. Accessed October 6, 2026.
Cunha-Cruz J, Wataha JC, Heaton LJ, et al. The prevalence of dentin hypersensitivity in general dental practices in the northwest United States. J Am Dent Assoc. 2013;144(3):288-296. doi:10.14219/jada.archive.2013.0116 (retrieved via PubMed)
About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.