Tooth ache is one of the more stupid and annoying disruptions to one's week. Dental hygiene can reduce the risk a lot, but only goes so far - for example, inflammation of roots of the tooth, with pus gathering underneath is something that just happens and you have about zero control over it, and without a dentist either releasing the pus through opening the root canal or removing the tooth altogether, the pain is simply debilitating and won't "go away" all on its own. At times old fillings fail, teeth can break, and generally that's one "mode of failure" of our bodies that can't be completely prevented or foreseen, but is fixable by a rather short and not overly complex medical procedure.
Besides obligatory dental hygiene (the edible toothpaste used by astronauts daily) how can astronauts deal with it? Aborting a mission due to tooth ache would be an awful waste. Do they have tools and training to extract one another's tooth? Or maybe some 'industrial strength' painkillers and antibiotics that would carry them through the remainder of the mission? Something else?