A temporary crown, or provisional restoration, is a short-term covering placed over a tooth prepared for a permanent crown. Its purpose is to protect the underlying, newly shaped tooth structure from damage, sensitivity, and bacterial contamination while the final restoration is fabricated in a dental laboratory. This interim cap also maintains the correct spacing and preserves the proper alignment of the bite, preventing surrounding teeth from shifting. Since permanent crown fabrication takes several weeks, the temporary crown ensures the patient can eat, speak, and smile comfortably during the waiting period.
Essential Materials and Pre-Procedure Steps
Creating a temporary crown begins with careful planning and the selection of specialized materials. The first step involves creating a negative mold, known as a putty matrix or diagnostic impression, which captures the shape of the existing tooth before preparation. This matrix, often made from polyvinyl siloxane (PVS) putty, serves as a template to form the temporary crown with the correct anatomical contours.
The temporary crown is commonly fabricated from materials such as Bis-Acryl composite resins or polymethyl methacrylate (PMMA) acrylic resins. Bis-Acryl materials are favored for their improved aesthetics, higher strength, and lower heat generation during setting. Alternatively, pre-formed polycarbonate crowns, which are prefabricated shells, may be selected and customized for a quicker solution. Prior to fabrication, the natural tooth must be precisely shaped, or reduced, to accommodate the thickness of the final crown material. This preparation removes enamel and dentin, leaving the tooth vulnerable and requiring immediate protection from the provisional restoration.
The Fabrication and Placement Procedure
Once the tooth is prepared and the matrix is ready, the provisional material is dispensed into the negative mold. For Bis-Acryl resins, an automix cartridge gun is used to inject the mixed material directly into the putty matrix, ensuring consistent blend and flow. The loaded matrix is immediately seated over the prepared tooth, pressed firmly, and held stable while the resin begins to set. The clinician waits for the material to reach its initial set, usually a matter of minutes, before carefully removing the matrix.
Removing the matrix leaves a rough, custom-formed temporary crown seated on the prepared tooth, which must be refined. The clinician trims away excess material, especially around the gum line, to establish a clean margin that seals the tooth preparation and prevents bacterial leakage. The temporary crown is then removed to be contoured and polished, ensuring its shape aligns properly with adjacent teeth and the opposing bite (occlusion). Careful adjustment is necessary to distribute chewing forces evenly, as an improper bite can cause the crown to fracture or dislodge.
After the temporary crown has been customized, polished, and checked for a precise fit, it is ready for cementation. A temporary luting agent, such as zinc oxide non-eugenol cement, is applied inside the crown and placed onto the prepared tooth. This cement is designed to be less retentive than permanent adhesives, allowing the temporary restoration to be easily removed without damaging the underlying tooth when the final crown is ready. The final step involves removing all excess cement from the margins and performing a last check of the patient’s bite and comfort.
Patient Care and Emergency Management
Patients must adhere to specific instructions to protect the temporary crown, as its materials are less durable than a permanent restoration. Patients should limit force by chewing on the opposite side of the mouth whenever possible. They must avoid hard, crunchy, or sticky foods (such as caramel, gum, and hard candies), which can easily crack the provisional material or pull the temporary crown free.
Daily cleaning requires modifying normal oral hygiene practices to prevent dislodgement. Brushing should continue as usual, but flossing around the temporary crown requires a specific technique: the floss is pulled out from the side of the tooth, rather than “popping” it up through the contact point, which could lift the crown. Mild temperature sensitivity is common; using a desensitizing toothpaste can help, but persistent discomfort should be reported.
If the temporary crown becomes loose, cracked, or falls off, the patient must contact the dental office immediately for recementation or replacement. Leaving the prepared tooth exposed risks sensitivity, decay, and the movement of surrounding teeth, which could prevent the permanent crown from fitting. If the crown is intact, a small amount of toothpaste or over-the-counter temporary dental cement can be placed inside it to temporarily reseat it until professional care is available.