Do I Need a Referral to See a Periodontist or Oral Surgeon?

I would suggest you speak to your dentist and have him refer to a periodontist who deal with 
gum defects. 
If not satisfied with your dentists answer, then i suggest you call a periodontist in your area.(or if have friend who can recommend one)

I would recommend that you ask your dentist for a referral of someone that they like to work with since the two will be collaborating on your case.  However, its not mandatory.  You can see a periodontist or oral surgeon without a referral.  If you will be finding a new dentist then you could ask the surgeon of your choice what cosmetic dentist they prefer to work with.

You do not necessarily need a referral to see a specialist.  They will do an exam prior to any treatment anyway.  It is nic eof you have already had an exam by the general dentist but it is not usually necessary.  Good luck.