I think it's a bit late to transition to dentistry.

Need more context. For me the point of the job is to support my basic needs and then use the excess money to acquire appreciating assets so I can retire. I lack the vision to consider any reasonable alternative, and this seems to be the default strategy for most of us employees.

The braver ones start their own businesses, which offers more potential reward but is higher risk.

Sales or marketing. Probably the latter, just because I've done a bit of the former before.