My dentist is suggesting front teeth veneers, as opposed to, crowns to fill in gaps near the gumline. which of the two is least invasive and why?

Veneers vs Crowns?: Veneers are less invasive as they only cover the front surfaces of the tooth and require far less tooth reduction. That is not to say which one would be most appropriate in your case. The more the tooth is damaged by decay and\or fillings, the more the need of crowns. Other factors play a role as well. Ask your dentist to go into more detail regarding his\her recommendations.

Veneers: Veneers are more conservative however you need to take into consideration if the pateitn is a ginder or a clincher also since we are looking for least invasive , have we considered ortho.

Veneers: Veneers are less invasive than crown as there is less reduction of tooth structure however there are many other factors that determines if veneer or crown which is the best option depending from case to case so your dentist would be the best to be evaluate ..In your case.