ObjectiveThe objective of this study was to develop and operationally define procedural performance metrics for the Class II posterior composite resin restoration procedure and to obtain face and content validity through a consensus meeting. MethodsA Metrics Group consisting of 4 experienced Consultants in Restorative Dentistry, an experienced member of staff from the Restorative Dentistry department in CUDSH and a senior behavioural scientist and education/training expert deconstructed the performance of the Class II posterior composite resin restoration and defined performance metrics. At a modified Delphi meeting, 20 experts in the field of Restorative Dentistry from 11 different Dental Institutions critiqued these metrics and their operational definitions before reaching consensus. ResultsInitially performance metrics consisting of 15 Phases, 45 steps, 42 errors and 34 critical errors were identified that characterize the performance of the Class II posterior resin composite procedure. During the Delphi panel these were modified and consensus was reached on 15 Phases (with a change to the initial sequence) with 46 Steps (1 added, 13 modified), 37 Errors (2 added, 1 deleted, 6 reclassified as Critical Error), and 43 Critical Errors (9 added). Consensus on the resulting metrics was obtained and face and content validity verified. ConclusionsIt is possible to develop and objectively define performance metrics that comprehensively characterize a Class II posterior composite resin restoration. It is also possible to achieve consensus on the metrics from a Delphi panel of experts and to confirm the face and content validity of those procedure metrics.