If oxycodone is reduced to a pure powder form would it cause numbing of the gums?

I tested an unknown white powder that I found after my husband's death and it numbed my gums and tested blue when using a police type test kit but his autoposy did not test positive for cocaine but for oxycodone. Is it possible that oxycodone would result in this result?

: http://alcoholdrugstreatment.info/if-oxycodone-is-reduced-to-a-pure-powder-form-would-it-cause-numbing-of-the-gums