Background: This Consensus Workshop dealt with diagnostic methodologies in the context of surveillance, screening, assessment of stage and grade, prognosis, monitoring and prediction of periodontal status. Several elements provided the impetus for the workshop, including the limited quality of available research on diagnostic tests, the rapid development of new technologies, the implementation of the 2018 classification and the declarations of the World Health Organisation on diagnosis and oral health. Aim: To update and evaluate the evidence on diagnostic methods, considering recent advances in knowledge and the implementation of the 2018 classification. Methods: The European Workshop Committee of the European Federation of Periodontology guided the development of a consensus report after commissioning eight systematic reviews within three working groups. The reviews were discussed during the in‐person consensus meeting involving 70 participants from 21 different countries. Results: Working Group 1 discussed innovations in traditional diagnostic approaches, justified manual probing as the reference standard and assessed the value of image‐based methods. Working Group 2 analysed diagnostic tests based on microbial and host biomarkers and genetic diagnostic tests. Working Group 3 covered emerging technologies to be used within dental and non‐dental clinical settings, focusing principally on the impact of questionnaire‐based assessments and artificial intelligence systems (AIS) in interpreting different data modalities. Conclusion: Although manual periodontal probing is firmly established as the reference standard, additional approaches based on imaging, biomarkers, host genetics, questionnaires and the development of emerging applied data science methods (e.g., AIS) are increasingly integrated in periodontal diagnostics.

Oxidative stress plays a significant role in the pathophysiology of periodontal disease (PD). Therefore, it is reasonable to suggest that a diet rich in antioxidants, such as several vitamins and essential minerals, may positively affect periodontal health. However, the evidence from the relevant literature is yet inconclusive. Studies evaluating the levels of intake of nutritional antioxidants in relation to periodontal status demonstrate contradictory results. This inconsistency could be attributed to heterogeneity in study design and methodological limitations, such as the small sample size, the assessment of periodontal status based on partial mouth measurements that usually underestimate the actual severity of PD, the lack of adjustment for confounders, which may obscure any potential but weak effect of nutrition, and the use of a 24 h recall to assess nutrient intake. Regarding the intervention studies that evaluated the effect of nutritional antioxidant supplementation as an adjunct to periodontal therapy, again, the results are not consistent. Few studies are randomized, and often different nutritional supplements are combined, making it difficult to distinguish the actual effect of each nutrient. Moreover, the dosage and duration of use of these supplements vary, rendering comparisons impossible. Therefore, better designed studies are necessary for the future. The assessment methods used for both PD and vitamin/mineral intake need to be more accurate and standardized to improve comparability. Also, prospective longitudinal and randomized controlled studies are important to establish the optimal dosing and the long-term effects of vitamin/mineral supplementation on periodontal health in different patient populations.