The general sign for "dentist" combines the sign TOOTH and
PERSON-agent.
DENTIST (TOOTH + PERSON-agent)




Note: In context you can drop the "PERSON-agent" sign and just sign "TOOTH."
You use a double motion as if tapping your tooth twice -- but you don't
actually make contact with the tooth. For example, if you sign "I/me
GO TOOTH" it is obvious that you are saying that you are going to the
"dentist."
Note: A lot of people "initialize" the sign DENTIST by doing it with a "D"
hand. If you do that version, you should not add the PERSON-agent sign.
I don't recommend using the initialized version since the traditional ASL
sign is very easily recognized.
Another version of "dentist" is to hit (lightly) the side of your mouth a couple times with the pinkie-side of
your fist.




Sample sentence:
"How often do you go to the dentist?" = YOU GO DENTIST HOW OFTEN?"