Читать книгу Fundamentals of Fixed Prosthodontics - James C. Kessler - Страница 94

If insufficient coronal tooth structure exists to retain the restoration within the crown of the tooth, an extracoronal restoration, or crown, is needed. It may also be used where there are extensive areas of defective axial tooth structure or if there is a need to modify contours to refine occlusion or improve esthetics.