Hi. I try to ask strategy questions - if the map is right then better chance to reach destination.
A better question to ask is what is the best way for you - a dentist - to promote your services.
Next question is what services and if it is consultations then specialized medical consultation portals or dentistry portals will serve your needs better. Your geography is not mentioned but say a sub second search on such portals in USA gives hundreds of results. https://duckduckgo.com/?q=dentist+consultation+portals+in+usa&ia=web You may be better off joining these due to focused reach.
On the other hand if you want to give business advise on dentistry or healthcare business or healthcare - say how to set up a dentistry business - then this can be a good forum. This forum is better for business advice.
I hope this helps. Let me know if we should talk further to better define go to market. All the best.