Approximately what percentage of tooth surfaces do pits and fissures cover?

• A. 5%
• B. 25%
• C. 40%
• D. 12.5%

Answer: (D)

Think about how the tooth’s surface areas are distributed. Pits and fissures are the narrow grooves on occlusal surfaces where plaque collects and cleaning is harder, but they make up only a portion of the enamel surface. Measurements of tooth surface area show that pits and fissures account for about one-eighth of the total enamel surface—roughly 12.5%. So the approximate percentage is 12.5%. The other numbers would over- or underrepresent how much of the surface is made up of these grooves. Despite being a smaller portion of surface area, pits and fissures are a major caries risk zone, which is why sealants are commonly applied there.