Phase Referenced Intervention (PRI): a Student Learning-resource for Caries Diagnosis

A prevention-based approach to caries management, in conjunction with adhesive materials technologies, encourages conservation of tooth structure by allowing carious lesion progression to dictate the extent of intervention rather than mechanically-driven mindsets of traditional preparation design. This requires that the phase of the carious process be correctly diagnosed and in particular the cavitation event – since preservation of an intact surface significantly deters carious progression by facilitating biofilm disruption during home-care. Objectives: to devise a heuristic resource to assist students in diagnostic decision-making that is simple, logical and consistent with current evidence. Methods: The PRI model was designed to incorporate the 3 site-references of the Mount & Hume Classification: however, PRI divides the disease continuum into incrementing phases according to the acronym ‘I-MAC' where (I) represents ‘Intact-surface' and (-) the ‘cavitation-event'. Thereafter (M) represents ‘Minimal-', (A) ‘Advancing-'and (C) ‘Complex-cavitation'. Referenced to these is the acronym ‘R-MAC', with corresponding modes of intervention of (R) ‘Remineralisation'; (M) ‘Minimal-'; (A) ‘Arrestive-' and (C) ‘Complex-intervention'. A computer application was developed for CD-ROM using Macromedia's Authorware 7®. This introduces the PRI concept, presents explanatory material (what to look for) and how to balance probabilities in assigning observed lesions to their appropriate ‘I-MAC' categories. As a learning aid, a drag-and-drop game is incorporated whereby students assign a dragable icon to diagnostic cells on a 3-level vertical grid (the CariesAbseil). Incorrect choices delay progression while correct ‘jumps' are positively commented – preparing students to fill in a corresponding planning-sheet (kept in patients' case-notes and used to construct a caries problem-list). Results: Creation of a heuristic framework to assist students to develop diagnostic reasoning-skills through interactive game-playing. Conclusion: A means of emphasising diagnosis as key to appropriate treatment-planning.