Christopher C.K. Ho
A provisional restoration is defined by the glossary of prosthodontic terms as a fixed or removable dental prosthesis designed to enhance aesthetics, stabilisation and/or function for a limited period of time, after which it is to be replaced by a definitive dental prosthesis. Often such prostheses are used to assist in determination of the therapeutic effectiveness of a specific treatment plan or confirming the form and function of the planned definitive prosthesis.
Provisionals serve the following functions:
- Pulpal protection from bacterial microleakage and thermal and chemical irritation, as well as providing a coronal seal for endodontically treated teeth.
- Maintenance and promotion of periodontal health. However, ensuring adequate contours and well-fitting margins is paramount in facilitating optimal oral hygiene. Moreover, a provisional restoration may also be used in clinical situations when the gingival margin may augment, such as after crown lengthening or following the removal of an overhanging restoration.
- Occlusion and positional stability. Inter-arch and intra-arch relationships are maintained through both proximal and occlusal contacts, preventing tipping, drifting and supra-eruption.
- Allowing adequate function. Patients should be able to function adequately, but should be cautioned on the temporary nature of the restoration.
- Providing adequate aesthetics. Acceptable aesthetics are required during the provisional phase as well as to assist in evaluating the planned intended changes.
- A diagnostic tool. Through duplication of the wax-up a preview of the intended aesthetic, occlusal and occlusal vertical dimension changes can be made (Figure 6.3.1). This allows adequate opportunity for the patient to receive a trial protoype to gain acceptance and approval. This is an important step when preparing multiple anterior restorations, as the patient may need time to adjust to the planned changes. It is the author’s view that the patient should be left to assess changes over a few days before returning to assess any modifications that may be required, as the transformations may take the patient some time to adjust to. Provisional restorations may also be used to measure the amount of reduction carried out by checking the thickness of the provisional restoration.