The answer would most likely be the second choice, that most patients who have a poor dental experience also have post-extraction complications.
Since it is not 100% of patients (and the fact that with dental/oral surgeon experience as a whole there are many possible factors as to why one would have a poor dental experience, like that it's way too expensive, the anesthetic was not administered properly, or someone was rude, etc.) causation could not be accurately identified without further research.
[A little personal note here, I actually had my wisdom teeth removed and one socket got infected a week later, but the procedure itself went well and I wasn't in too much pain. Though I imagine that in many real-life scenarios, a complication could certainly make the experience worse.]
