The role of nicotine, cotinine and caffeine on the electrochemical behavior and bacterial colonization to cp-Ti

Although smoking promotes deleterious effect to bone healing, there is a lack of study investigating its role on the implant structure and biofilm growth. We hypothesized that nicotine, cotinine and caffeine would impair the corrosion resistance of commercially-pure titanium (cp-Ti) and would enhance Streptococcus sanguinis biofilm growth. Neither the smoking products nor the caffeine affected the corrosion tendency (P>.05) and the oxide layer resistance (P=.762) of cp-Ti. Lower capacitance values were noted in the presence of nicotine (P=.001) and cotinine (P=.0006). SEM showed no pitting corrosion, and the EDS spectra did not differ among groups. Nicotine (300μg/mL) induced higher surface roughness (P=.03) and greater surface change of cp-Ti. Nicotine at 3μg/mL, and cotinine at 0.3 and 3μg/mL increased the number of viable cells (P.05). These findings suggest a greater biofilm accumulation in smokers, a risk factor that may lead to peri-implantitis. [Display omitted] •Smoking products and caffeine had no influence on the corrosion behavior of cp-Ti.•Nicotine and cotinine enhanced Streptococcus sanguinis biofilm growth.•Biofilm carbohydrate content increased under nicotine and cotinine presence.•Biofilm accumulation is expected in smokers, a risk factor for peri-implantitis.