sylvie,
I'd ask and trust Dr. Samuel Pelcman on Av. Sta Fe to refer you to an oral surgeon he thinks best for you if the type of surgery you need isn't one he does himself.
I lived in Canada until recently. Every complex or expensive thing dentists there said I needed I always pass by Dr. Pelcman first. I trust him far more than I did them. By hiring him, I saved myself a lot of money, pain and unnecessary dental surgery.
He was also able to do things that the 2 top specialists in my former city were unable to do because, they said, the surgery I needed required too high a degree of exactness so as to avoid cutting some major blood vessel. (One assured me I'd bleed to death on her floor before an ambulance could arrive should she make the smallest error!) Two months later in BA, Dr. Pelcman examined me and did the surgery. Neither he nor his son, Martin, could understand how my 'home' dentists could find the surgery I needed difficult at all! I went dancing the day after surgery. No problem at all.
Thus, I refer to you the best dentist who's ever worked on me in the world. And I've been a patient of 3 countries' foremost dental specialists. Dr. Pelcman is that good and he's kind and honest.
Best wishes.