Which of the following statements about the DMFT/DMFS index is FALSE?

The DMFT (Decayed, Missing, Filled Teeth) index is irreversible — once a tooth is counted as decayed, missing, or filled, it cannot revert to being counted as sound/healthy. Decayed teeth can be filled, but they are still recorded as 'F' (filled), not removed from the index. This is the fundamental limitation of the DMFT index: it accumulates over time and never decreases. The statement 'it is reversible' is therefore FALSE, making it the correct answer to this false-statement question.