The use of osseointegrated implants as a foundation for the prosthetic replacement of missing teeth has become widespread in the last decade.1 Owing to the remarkable success of dental implants, there has been growing interest in identifying factors associated with implant failure. Given the well-documented deleterious effect of smoking on wound healing after tooth extraction and its association with poor quality bone and periodontal disease, a negative effect of tobacco use on implant success is to be expected. Oxidative stress occurs as a result of an overproduction of ROS (reactive oxygen species) not balanced by an adequate level of antioxidants. ROS are highly reactive molecules which consist of a number of diverse chemical species, including radical and non-radical oxygen species. Many diseases have been linked to oxidative stress including bone diseases among which one of the most important is the osteoporosis. Changes in ROS and/or antioxidant systems seem to be involved in the pathogenesis of bone loss. ROS induce the apoptosis of osteoblasts and osteocytes, and this favours osteoclastogenesis and inhibits the mineralization and osteo-genesis. Antioxidants either directly or by counteracting the action of oxidants contribute to activate the differentiation of osteoblasts, mineralization process and the reduction of osteoclast activity. In fact, a marked decrease in plasma antioxidants was found in aged or osteoporotic women. Therefore, this study was planned to address the gap in knowledge as to whether antioxidant therapy can improve implant stability and reduce crestal bone loss in smokers and non-smokers receiving implant treatment