The radiographic assessment of pulp size: validity and clinical implications.

A study was performed to determine if the radiographic appearances of the coronal pulp spaces provide a reliable indication of pulp size in maxillary incisors. The use of student and staff assessor groups showed that length of clinical experience did not influence assessments of the size of the coronal pulp. A measuring grid, superimposed over a duplicate set of films, decreased the students' perception of the size of the coronal pulp. The presence of small carious lesions or restorations did not affect the assessments for either of the film types viewed. The data were pooled to give a mean radiographic size for each tooth, and the teeth were sectioned. Analysis of the results demonstrated the value of carefully viewing incisor crowns shown on pre-operative periapical radiographs. Sectioning of the teeth suggested that very little dentine may remain to protect the pulp after routine crown preparations. Even the very conservative preparations sometimes necessary when providing veneers might be considered a hazard to the pulp, as they may expose large areas of the dentine of an immature tooth.