Ace the California RDA Written Exam 2026 – Drill, Fill, and Thrill Your Way to Success!

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.