**8.5 Smoking**

Smoking has a detrimental effect on tissue healing. Nicotine can reduce the nutrition to the tissues as a result of its vasoconstrictive effect on the blood vessels during the early osseointegration phase. Based on the available studies, smoking can be considered as a greatest identifiable risk factor for peri-implantitis. The extent of osseointegration as well as the plaque accumulation around dental implants was compromised among csmokers. A 10-year cohort study reported that peri-implantitis developed for 28% of all implants in smokers, while the corresponding incidence was 6% of all implants in non-smokers [39]. Several cross-sectional studies also showed a higher prevalence of peri-implantitis among smokers [15, 47, 48]. A systematic review of prospective and retrospective studies indicated an enhanced risk of biological complications among smokers; similarly, a meta-analysis indicated an enhanced risk of implant failure among smokers [49]. Studies indicate smoking as the greatest identifiable and most often cited risk.
