Classifications in medicine/dentistry are required so that clinicians can properly diagnose and then adequately treat their patients. However, they are also important for scientists to study the prevalence and the etiopathogenesis of diseases, as well as their prognosis, course and treatment. This brief review is based on the four consensus reports (Chapple et al, 20181, Papapanou et al, 20182, Jepsen et al, 20183, Berglundh et al, 20184) and the introduction (Caton et al 20185) presenting the results of the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. The consensus conference was jointly organised by the American Academy of Periodontology and the European Federation of Periodontology and conducted in November 2017 in Chicago. It was attended by 110 experts from all over the world. The results were published in the Journal of Periodontology and the Journal of Clinical Periodontology in June 2018. Keywords: classification, dental implant, peri-implant disease, periodontal disease, periodontology