In the United States, the tendency is not to perform implants on smokers, and to condition the providing of implants to quitting smoking. In my work, the many years and experience (thousands of implants, over 24 years, I found no difference between smokers and non-smokers. Furthermore, it is difficult to absolutely isolate smoking as the factor of uncertainty in implant failure. Many variables might cause implant failure, such as: a doctor's skill, warming of the bone, contamination, tooth erosion, teeth tightening, etc.