Tobacco smoking,alcohol and drug abuse have a bad influence on implant treatment.It is well established that tobacco smoking is a very important risk factor in periodontitis and that it affects healing.This has been demonstrated extensively in the dental,medical and surgical literature.A few studies have shown that the overall mean failure rate of dental implants in smokers is approximately twice that in non-smoker.In longitudinal studies,smokers have shown to have more significant marginal bone loss around their implants than non-smokers.Smokers should be warned of this association and encouraged to quit the habit.Protocols have been proposed that recommend smoker to give up for at least two weeks prior to implant placement and for several weeks afterwards.