Studies assessing the role of ICTP levels in GCF or peri-implant crevicular fluid as a diagnostic marker of periodontal disease activity have reported promising results so far (Oringer et al. 1998, 2002). ICTP was suggested to predict future bone loss, to correlate with clinical parameters and putative periodontal pathogens and also to reduce following periodontal therapy (Giannobile 1999). Apart from the direct cigarette smoke-mediated effects, tissue damage mediated by impaired balance of bone