If endodontic treatment cannot be completed in one visit, it is essential that a temporary restorative material is used as an inter-appointment dressing that will not permit access to bacteria or oral fluids. Even when the root canal treatment has been completed, a well-sealed temporary restoration is necessary prior to the placement of a permanent restoration. The material should prevent contamination of the root canal system and must be sufficiently strong to withstand the forces of mastication. Two different temporary materials are recommended. Of the many proprietary materials, Cavit has been shown to provide the best seal.
Cavit provides a good seal, is simple to apply and quick to set. On the other hand, it lacks strength and will not stand up to masticatory forces. It should be confined to single surface fillings for periods not exceeding a week. However, the shape of an endodontic access cavity is not retentive, and all such materials will either leak or be lost entirely in time. Any ingress of microorganisms may reinfect a prepared canal, and the time saved by using a rapid technique may be severely lost if such leakage occurs. Thus the use of a glass-ionomer cement should be considered. It is adhesive, antibacterial, stands up well to forces of mastication and is more stable than other materials. It is a useful routine, with an inter-appointment dressing, to place a sterile pledget of cotton wool in the pulp chamber, followed by a layer of gutta-percha. The temporary restorative material is then placed over the guttapercha (Fig. 16). At the next visit, a high-speed bur may be used to remove the temporary restoration without any danger of filling material lodging in the canal entrances or blocking the canals. The gutta-percha
provides a base for the restorative material and prevents the bur becoming caught in the cotton wool when the temporary filling is removed.
Cavit provides a good seal, is simple to apply and quick to set. On the other hand, it lacks strength and will not stand up to masticatory forces. It should be confined to single surface fillings for periods not exceeding a week. However, the shape of an endodontic access cavity is not retentive, and all such materials will either leak or be lost entirely in time. Any ingress of microorganisms may reinfect a prepared canal, and the time saved by using a rapid technique may be severely lost if such leakage occurs. Thus the use of a glass-ionomer cement should be considered. It is adhesive, antibacterial, stands up well to forces of mastication and is more stable than other materials. It is a useful routine, with an inter-appointment dressing, to place a sterile pledget of cotton wool in the pulp chamber, followed by a layer of gutta-percha. The temporary restorative material is then placed over the guttapercha (Fig. 16). At the next visit, a high-speed bur may be used to remove the temporary restoration without any danger of filling material lodging in the canal entrances or blocking the canals. The gutta-percha
provides a base for the restorative material and prevents the bur becoming caught in the cotton wool when the temporary filling is removed.