Salivary type I collagen degradation end-products and related matrix metalloproteinases in periodontitis Gursoy UK, Ko ¨no ¨nen E, Huumonen S, Tervahartiala T, Pussinen PJ, Suominen AL, Sorsa T. Salivary type I collagen degradation end-products and related matrix metallopro- teinases in periodontitis. J Clin Periodontol 2013; 40: 18–25. doi: 10.1111/jcpe.12020. Abstract Aim: Type I collagen degradation end-products and related matrix metalloprotein- ases (MMPs) were examined aiming to detect potential markers of periodontitis in saliva, with high sensitivity and specificity. Materials and Methods: The salivary concentrations of MMP-8, MMP-9 and MMP-13, tartrate-resistant acid phosphatase serum type 5b, C-terminal cross- linked telopeptide of type I collagen (CTx), N-terminal cross-linked telopeptide of type I collagen (NTx) and cross-linked carboxyterminal telopeptide of type I collagen were analysed in 230 subjects. Oral health examination included panoramic radiography. Results: The concentrations of MMP-8, MMP-9 and MMP-13 in saliva were higher in subjects with generalized periodontitis than in controls. Of the tested salivary markers, MMP-8 was the only marker capable of differentiating subjects with severe alveolar bone loss from those with slight bone loss (p < 0.001). The association between the salivary MMP-8 levels and periodontitis remained signifi- cant after the adjustment with age, gender and smoking. In addition, significant correlations were found between the tested markers and periodontal parameters. Conclusion: Enzymes and end-products of type I collagen degradation have different associations with each other and with periodontal status that may reflect their roles in the cascade leading to alveolar bone loss. MMP-8 is a strong biomarker candidate for detecting alveolar bone destruction. Ulvi K. Gursoy 1,2, , Eija Ko ¨ no ¨ nen 1,2 , Sisko Huumonen 1 , Taina Tervahartiala 3,4 , Pirkko J. Pussinen 3,4 , Anna L. Suominen 5,6,7 and Timo Sorsa 3,4 1 Institute of Dentistry, University of Turku, Turku, Finland; 2 Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare (THL), Helsinki, Finland; 3 Institute of Dentistry, University of Helsinki, Helsinki, Finland; 4 Department of Oral & Maxillofacial Surgery, Helsinki University Central Hospital, Helsinki, Finland; 5 Unit of Living Conditions, Health and Wellbeing, Department of Environmental Health in Environmental Epidemiology Unit, National Institute for Health and Welfare (THL), Kuopio, Finland; 6 Institute of Dentistry, University of Eastern Finland, Kuopio, Finland; 7 Department of Oral and Maxillofacial Surgery, Kuopio University Hospital, Kuopio, Finland Key words: collagen type I; periodontitis; saliva Accepted for publication 9 September 2012 Pathological resorption of alveolar bone in periodontitis is an outcome of an infection-induced chronic inflammation, with remissions and progressions, and the pathogenesis of periodontitis shows similarities with other bone affecting diseases (Goodson et al. 1982, Silva et al. 2008, Darveau 2010). Excessive Conflict of interest and source of funding statement The authors declare that they have no conflicts of interests. This study population is part of the Health 2000 Health Examination survey, organized by the National Public Health Institute (presently National Institute for Health and Welfare, Finland), and partly sup- ported by the Finnish Dental Association and the Finnish Dental Society Apollonia. Financial support was received from the Finnish Cultural Foundation (for U. K. G), the Sigrid Juselius Foundation (for P. J. P.), the Academy of Finland (grant 78443 for E. K.) and the Helsinki University Central Hospital Research Foundation (for T. S.). Timo Sorsa is an inventor of US-patents 5652227, 5736341, 5866432 and 6143476. © 2012 John Wiley & Sons A/S 18 J Clin Periodontol 2013; 40: 18–25 doi: 10.1111/jcpe.12020