The aim of this paper is to provide a broad international perspective on aspects of the RTI/UNC systematic review, to introduce relevant literature not cited, and to make recommendations for clinical practice education and research suggested by the evidence. Clinical caries diagnosis represents the foundation on which the answers to most of the consensus questions will be based. This paper highlights needs for being clear about definitions and nomenclature; understanding the importance of the concepts underlying the D1 and D3 diagnostic thresholds used widely within the RTI/UNC Review; and appreciating that the diagnostic challenge now faced by clinicians is significant and is becoming more complex as the presentation and distribution of the disease changes over time and the range of preventive and operative treatment options expands. A series of recommendations informed by the evidence are made, including a rather contentious issue for many clinicians concerning the lack of evidence supporting the continued use of a sharp explorer as a diagnostic tool for primary caries diagnosis. This practice should be discontinued as it may cause some harm to the patient and yet fails to provide a significant balancing diagnostic benefit. Finally, it is suggested that dentistry should learn from the developing evidence base in medicine on how best to disseminate the findings of reviews and promote appropriate changes in clinical practice.