ArRejaie AS, et al. - Investigators included 32 cigarette smokers (CS) (group 1), 31 individuals vaping e-cigarettes (e-cigs) (group 2), and 32 non-smokers (NS) (group 3) to examine the clinical and radiographic peri-implant parameters and levels of matrix metalloproteinase (MMP)-9 and interleukin (IL)-1β levels among these groups. Significantly higher values of bleeding on probing in group 3 vs groups 1 and 2 were recorded. They found significantly higher plaque index, probing depth ≥ 4 mm, and mean concentrations of both MMP-9 and IL-1β in groups 1 and 2 vs group 3. In group 1, MBL was significantly higher vs group 2 and group 3. They concluded compromised peri-implant health among CS vs vaping candidates and NS. They suggested a greater peri-implant inflammatory response due to increased levels of proinflammatory cytokines in CS and vaping people.