Periodontists and douches are interchangable in the real world,
while it is insensitive to call an actual useful feminine product a periodontist (as most periodontist will probably never enter a woman multiple times in their lifetime, and women would indeed object to have a periodontist inserted willingly, if for namesake only), quite a few periodontist acknowledge their non-certified secondary title of ..'douche' and try ever so hard on a daily basis to keep the honor.
A foreign trained dentist who goes to extra schooling to learn how to be a better hygienist. Usually so worried about the tissue around the teeth, it takes them 3 hours to non-lethally subluxate a tooth, 1 hour to actually remove the tooth, and 1 hour to suture.
I should have gone to the oral surgeon because that ass tard periodontist took 5 hours to remove the tooth. What is interesting is that he gowned up, put on booties, a surgical cap, and when he came into the room I thought I was going to have neurosurgery.