In another recent study by our group (Gürlek et al. 2009) similar salivary ICTP levels were detected in smoker, non-smoker and ex-smoker patient groups with similar clinical periodontal findings. Smoking status was confirmed by salivary cotinine analysis but there was no clinically healthy control group in that study and the number of teeth present, average probing depths and attachment levels were all similar in the three study groups. There were no significant differences in saliva ICTP concen