Dental If less than 27% H3PO4 is used for acid etching then, A It precipitates less. B It forms dicalcium phosphate monohydrate. C The formed precipitate cannot be rinsed off. D All of the above. 💡 Explanation If less than 27% H3PO4 is used for acid etching then, ✓ Correct Answer: D. All of the above.