How do I tell my BF that he needs to take better care of his teeth?

How do I tell my BF that he needs to take better care of his teeth? He had never had good dental hygiene. He smokes and drinks coffee. I noticed today that his teeth actually look stained/dirty. I hate to say it but it grossed me out. How do I tell him he needs to do something? Perhaps a tooth whitener, or a trip to the dentist. He never goes to the dentist by the way. help!!
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Make a point of talking up your next visit to the dentist. He may have a phobia of some sort. Have him accompany you. Find some data on teeth/health tie-ins. Mention them in casual conversation. ("You know I read the most startling thing in--- the other day. Teeth problems can affect not only your ---, but your---. I'm going to see my dentist on ---. When was the last time that you visited yours?"). It could work.
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