Cariology (uncountable) The study of dental caries and its development. A joint workshop of ORCA and the IADR Cariology Research Group on the Terminology of Dental Caries and Dental Caries Management was organized on February 6–7, 2019 in Frankfurt, Germany, in order to discuss and reach consensus on the definitions of the most commonly used terms in cariology. The inspiration to organize the present workshop was stimulated by continuous ongoing discussions among researchers, clinicians, public health professionals, and policy makers regarding the most appropriate terms to describe conditions and characteristics of dental caries and related matters. The organizers of the workshop agreed that the benefits of a common terminology would include facilitating researchers to share concepts, to document conditions as well as to interpret them in the same way, and to ease communication with clinicians. Thus, the aims of the workshop were: (i) to identify the available terms in the literature used to describe dental caries and related matters, (ii) to select the most commonly used terms and review their definitions, based on the current concepts, and (iii) to discuss and agree upon the most appropriate terms and definitions. Terms related to the definition, diagnosis, risk assessment, and monitoring of dental caries were included.The Delphi process was used to establish the terms or statements and definitions to be considered using the nominal group method favored by consensus. Prior to the workshop, a group of six experts suggested by the ORCA Board independently provided commonly used terms related to dental caries. The total number of terms suggested was. After removing duplicates and unnecessary words terms were taken forward by the Editor-in-Chief of Caries Research, the official journal of ORCA. This number was then revised by several working group members (V.M., B.N., and J.C.C.) and further reduced to 60 by removing synonymous terms (e.g., Caries, Dental caries, Caries disease) and the terms that do not relate directly to dental caries (e.g., Coding, Detection aid). The provisional definitions of the selected terms were provided by the chairpersons of the working group (V.M. and B.N.) and circulated to the group of 17 experts who independently decided on the appropriateness of the definitions. In total, 16 researchers with considerable research expertise in cariology participated in the workshop and in the process of reaching consensus about the definitions of the selected caries terms. Following discussions at the workshop, the final number of terms ended up at.A priori, consensus was established as  agreement among the participating experts on the definition of each term. The decisions were made following thorough “round table” discussions of each term, and confirmed by secret voting using an electronic program [Mentimeter, 2019]. The consensus percentage agreement is presented in parentheses next to each term Caries diagnosis is the clinical judgement integrating available information, including the detection and assessment of caries signs (lesions), to determine presence of the disease. The main purpose of clinical caries diagnosis is to achieve the best health outcome for the patient by selecting the best management option for each lesion type, to inform the patient, and to monitor the clinical course of the disease