It has been 3 weeks since my dental implant surgery. I was wondering if I could smoke a cigarette or two?

Nicotine and the other caustic chemical in cigarette smoke adversely affects blood supply to the tissues surrounding the implant.  It is equivalent to putting a tourniquet around your leg when it is trying to heal.  Use the patch adn give this implant the best chance to survive.

Smoking delays healing. The implant takes 3-6 months to fully heal. Any amount of smoking during that time may negatively affect the healing and cause the implant to fail. Try not to smoke as long as possible to prevent failure of the implant. 

You haven’t smoked at all, not one cig for 3-4 weeks already and just NOW you’re having urges to smoke 1-2? Implant takes 6 months to integrate with your jaw bone. The more cigarette you smoke, the more potential negative impact it may have with implant integration. The less you smoke, the better. Since you’ve already stopped for a month, why not just keep on going? 

Smoking negatively effects the healing of any dental procedure.  It takes a minimum of 3 months for the implant to oseointegrate (become one with the bone), so smoking could cause this implant to fail.  I would recommend staying away from smoking completely in order for your dental work to be successful.  It may be hard to stop the habit, but 3 weeks is a great head start!