Chapter 1
Introduction
Aim
To familiarise the reader with planning indirect restorations, taking into consideration the importance of previous dental history. The reasons for placing indirect restorations are reappraised.
Outcome
On reading this chapter the reader will better understand the importance of prevention and maintaining pulp and periodontal health in the provision of successful indirect restorations.
Introduction
To the reader, it may seem strange that a text on successful indirect restorations should begin with a chapter discussing failures. But in terms of success, it is probably the most important subject as many indirect restorations are replacement restorations. The restorative cycle, once established, will continue unless lessons are learnt from failure events. This chapter will consider the:
failure of direct and indirect restorations
maintenance of pulp health
importance of periodontal health
importance of pulp vitality.
Why Indirect Restorations?
Most indirect restorations are placed to restore the contour, function and appearance of teeth previously restored with plastic restorations. In restoring broken down or damaged teeth with plastic restorations, it is sometimes difficult to achieve appropriate contact areas (Fig 1-1) and occlusal form (Fig 1-2). Indirect restorations such as crowns, onlays and inlays enable the contact areas and the occlusal form to be controlled in the laboratory. The majority of extensive restorations are placed because of primary caries, or caries adjacent to existing restorations. Others will be placed following a fracture of tooth tissue, classically a cusp fracture associated with an occlusoproximal restoration (Fig 1-3). Relatively few extensive restorations are placed as a consequence of trauma.
Fig 1-1 Bitewing radiograph showing a ledge on the amalgam restoration in the LR4. This occurred as the LR4 has an extensive defect, making it difficult to develop a tight contact area while keeping the matrix band adapted cervically.
Fig 1-2 Given the extent of this cavity, it is difficult to place an amalgam restoration with adequate occlusal contour.
Fig 1-3 The MOD restoration in this lower molar tooth, although not large, has weakened the tooth and the lingual cusp has fractured.
Why do Indirect Restora
