Hi Baker~
If you take into consideration whether you are an extrovert or introvert I think this might really help you with making a decision. If you like interacting with people, a hygienist would probably be more rewarding. My hygienist is in her late 50's and she does a great job, she really likes what she does. I don't know anything about making dentures, but I do know what it is like to work in a lab. If you don't mind not interacting much with others maybe the lab would suit you better.I too am 42 ~ don't let your age discourage you from going to hygienist school. I still toy with going back to school to get an RN degree. I would really like to do a more humanitarian type job, but I love what I do and the flexibility that it provides.
Just my op! Good luck in your endeavor, keep us posted
trisha