If it was dismissed and sealed then probably not. If it does show up and shows up as dismissed it shouldn't be used against you in hiring. I also believe that if you were denied licensing by the board you would be entitled to a hearing before that board at which point you could show your prescription paperwork and your record of dismissal. Feel free to call me at 516-587-9786 with any questions.
The Board of Education background check is more thorough than your standard background check, so I believe that it will show up. Since you had a prescription and the case was dismissed, it should not be used against you as a basis for denying you a position.
I believe that the Board of Education is an a category that is an exception to the general rule that sealed records don't show up. I believe that educational entities can see these records on a background check. Call the Department of Criminal Justice Services in Albany to get a definative answer.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 385-8015 or via email at Eric@RothsteinLawNY.com. The above answer is for informational purposes only and not meant as legal advice.