I was not told not to smoke after a dental implant. I smoked about 3-5 cigerattes a day. Does that mean it’s doomed to fail?

Maxillary implants are more affected by smoking then lower implants.  Smoking will increase the risk of failure but many smokers are successful with implants.  Avoid sinus lifts or bone grafts as they are most affected by smoking.

I tell my patients the longer they can wait to resume smoking, the better.Keep in mind that smokers can have up to double the failure rate, but it doesn't necessarily mean you're destined to have a failure.
Once the gum tissue has completely closed over the surgical site, the immature bone won’t have direct access to the smoke and so it shouldn’t have much of an effect.
I hope you found this information to be helpful,
Dr. Champagne