California Registered Dental Assistant (RDA) Written Practice Exam

Why are pits and fissures susceptible to caries?

1. They accumulate more plaque

2. They are more sensitive

3. Fluoride is less effective in these areas and these areas are difficult to clean

4. They have a different enamel composition

The correct answer is: Fluoride is less effective in these areas and these areas are difficult to clean

Pits and fissures are grooves and depressions found on the surface of teeth that can easily trap food and bacteria, making it difficult to remove them through brushing. As a result, plaque can easily build up in these areas, making them more prone to caries or tooth decay. In addition, the shape and depth of pits and fissures can make it challenging for fluoride to reach and protect these areas, making them less effective in preventing caries. Enamel, the protective layer of the tooth, is also thinner in pits and fissures, making it more susceptible to damage from bacteria and acid. Therefore, all of the other options listed - plaque accumulation, sensitivity, and enamel composition - contribute to the increased susceptibility to caries in pits and fissures, but ultimately it is the difficulty in cleaning and limited protection from fluoride that make C the correct answer.