True or false: a single toothbrush will clean pits & fissures very well.

• A. True
• B. False — even a single toothbrush bristle is too large to enter and clean pits and fissures
• C. False — pits & fissures can be cleaned with routine brushing
• D. False — cleaning pits & fissures is unnecessary

Answer: (B)

The main concept is that pits and fissures on tooth surfaces are too narrow for a single toothbrush bristle to access effectively, so brushing alone cannot clean them well.

Pits and fissures are deep, irregular grooves where plaque can accumulate. The diameter of a typical toothbrush bristle is about 0.1–0.3 mm, which is larger than many fissure entrances. Because a lone bristle can’t reach deep into these crevices, mechanical cleaning from brushing doesn’t remove plaque well from the base of pits and fissures. This is why routine brushing, while essential for outer surfaces, isn’t sufficient to clean these areas completely.

To manage cleanly, other tools such as interdental brushes or floss are used to disrupt plaque at the openings, and many clinicians place fissure sealants to protect these grooves from caries. Regular fluoride toothpaste helps prevent decay, but it doesn’t substitute for the physical cleaning access required inside pits and fissures.