20. Which one of the following is true about properties of an ideal irrigant? IV. Organic tissue solvent Inorganic tissue solvent Antimicrobial action Toxic High surface tension VI. Lubricant a. Only I b. I and III c. II and IV d. I,II,III and VI e. I,II,III,IV ,V and VI

The correct answer is:<br /><br />b. I and III<br /><br />Explanation:<br />- I. Organic tissue solvent: This is true about properties of an ideal irrigant. An ideal irrigant should be able to dissolve organic tissue.<br />- III. Antimicrobial action: This is also true about properties of an ideal irrigant. An ideal irrigant should have antimicrobial properties to help prevent infection during dental procedures.<br />- II. Inorganic tissue solvent: This is not typically a property associated with an ideal irrigant.<br />- IV. Toxic: An ideal irrigant should not be toxic.<br />- V. High surface tension: This is not typically a property associated with an ideal irrigant.<br />- VI. Lubricant: This is not typically a property associated with an ideal irrigant.<br /><br />Therefore, the correct answer is b. I and III.