The "simple" test for candida/thrush is that it can be scraped off with your fingertnail. If it cannot, then you are looking at something else, and there are a variety of thigns - of course leucoplakia being at the top of the list. Scraping the white off with your fingernail isn't going to make anything better, Diflucan will still be required, I mention this just as a way of determining that it is actually candida.