Approximately how much time is required for progression of incipient to clinical cavitated caries on smooth surface?: (A) 10+-6 months, (B) 18+-6 months, (C) 25+-8 months, (D) 13+-3 months
Answer is B. The time for progression from incipient caries to clinical caries (cavitation) on smooth surface is estimated to be 18 months, plus or minus 6 months.