New classification system for periodontal and peri-implant diseases

Since 1999, we have become used to the periodontal diseases classification system devised by Armitage.¹ This defined periodontal diseases (but not, at that time, peri-implant diseases) into eight categories and recognized periodontitis in two forms, chronic and aggressive. With advances in knowledge from both clinical and biological research over the last two decades there was a consensus of opinion that the time was right for the development of a new classification system based on our current understanding of the pathophysiology of both periodontal and peri-implant diseases. Early in 2015, planning commenced for a World Workshop on the Classification of Periodontal and Peri-implant Diseases, co-sponsored by the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP). The Workshop took place in Chicago from 9 to 11 November 2017 and the proceedings of the Workshop were published in June 2018, coinciding with the Europerio 9 international conference in Amsterdam the same month. The Workshop comprised four main working groups: