Introduction

The EFP project 'Perio & Caries’ builds on the outcomes of Perio Workshop 2016, devoted to “The boundaries between dental caries and periodontal disease”, jointly organised by the EFP with ORCA (European Organisation for Caries Research) in November 2016 and sponsored by Colgate. Perio Workshop is a leading annual scientific meeting focusing on state-of-the-art issues relating to gum health and gum disease, organised by the EFP in La Granja, Spain under the chairmanship of Mariano Sanz.

During Perio Workshop 2016, 75 leading global cariologists and periodontists from ORCA and EFP reviewed, for the first time, all available evidence on common links between these preventable oral conditions. Special emphasis was placed on associated causes, risk factors and prevention that may influence both periodontal diseases and caries. The conclusions of Perio Workshop 2016 are publicly available in a special open-access supplement of the EFP’s Journal of Clinical Periodontology.

Caries and periodontal diseases share common genetic, aetiological and environmental factors, although they follow different trajectories. As a result, they have always been considered as separate entities, however no longer. The project ‘Perio & Caries’ came about to disseminate these identified similarities - and the distinct characteristics of each entity - and to recommend clear preventive measures for individuals and the population at large.

The consensus reports produced by the four working groups at Perio Workshop 2016 examined the role of microbial biofilms; the interaction of lifestyle, behaviour and systemic diseases; prevention and control; and age-related effects, all in relation to dental caries and periodontal diseases.

Other major conclusions of Perio Workshop 2016 and the ‘Perio & Caries’ project include:

• Micro-organisms associated with both caries and periodontal diseases are metabolically highly specialised and organised as multi-species, microbial biofilms.
• The progression of these diseases involves multiple microbial interactions driven by different stressors. With caries, exposure to dietary sugars and fermenting organic acids results in increased quantities of acidogenic and aciduric species. In gingivitis, plaque accumulation at the gingival margin leads to inflammation and increased proportions of proteolytic and often obligate anaerobic species.
• There is moderately strong evidence for a genetic contribution to periodontal diseases and caries susceptibility, with an attributable risk estimated at up to 50 percent.
• There has been a global decline in the prevalence of caries and probably periodontal diseases, although the increase in the global population and tooth retention imply a bigger burden of disease at the population level.