Which of the following is an example of secondary prevention?

• A. Oral prophylaxis
• B. Water fluoridation
• C. Sealants
• D. Drilling and filling a cavity

Answer: (D)

Secondary prevention centers on actions taken after a disease process has begun to stop its progression and prevent complications. In dentistry, once decay has formed, removing the decayed tissue and restoring the tooth with a filling directly addresses the lesion and halts further deterioration, helping preserve tooth structure and prevent pain or more extensive treatment later. That’s why drilling and filling a cavity is the best example. The other options—cleaning and prophylaxis, water fluoridation, and sealants—prevent the disease from occurring in the first place, which is primary prevention. The key idea is using treatment after decay appears to stop its advance rather than preventing it from starting.