Material that's bad for the mouth? Crossword Clue

 The crossword clue "material that's bad for the mouth" can be answered with the word SILT. It is a 4-letter word that can be used as a crossword clue.

Silt is a fine-grained sediment that is made up of tiny particles of sand, clay, and other materials. It can be found in rivers, lakes, and oceans. Silt can be harmful to the mouth because it can scratch the delicate tissues inside the mouth. It can also cause tooth decay and gum disease.

Here are some other possible answers for the crossword clue "material that's bad for the mouth":

TAR (4 letters)

ASH (3 letters)

ASHES (5 letters)

CEMENT (6 letters)

ASPHALT (7 letters)

I hope this helps! Let me know if you have any other questions.