Inside Dental Technology
March 2011, Volume 2, Issue 3
Published by AEGIS Communications
Fabricating Esthetic Provisionals
Meeting the challenge of missing tissue with a provisional restoration in the esthetic zone.
By Peter Pizzi, CDT, MDT, FNGS
Often technicians are so focused on the many different restorative options and procedures available that they sometimes forget the importance of the wax-up and provisional restoration, and the key role they play in the success of the final outcome. Although the wax-up is the foundational plan for the structure and support of the final prosthesis, transferring that preliminary information to the temporary becomes critical to successful case completion.
Fabricating esthetic provisionals is a functional test-run of the case and should also be considered the esthetic trial phase. Remember that the wax-up is still somewhat of an estimation of what the dental technician and the rest of the dental team think the correct case approach should be, which is confirmed either through an intraoral mock-up or at the provisional stage. The biggest challenge is that many tend to view the provisional as merely a "temporary" restoration while waiting for the final, which is not the role the provisional plays in restorative dentistry.
There is also the patient dynamic. The patient may be very conscious of esthetic appearance, especially in the esthetic zone; yet, they may be unaware of how lip dynamics, for example, can cover up what is otherwise an undesirable esthetic situation. This is correctable at the provisional stage or final prosthesis.
Provisionalization serves three primary purposes:
- Tooth position: The provisional restoration should be the key determinate in establishing the incisal edge position, midline, horizontal plane, and starting point for basic tooth shape, ie, morphology, position, embrasure space, and possible rotation.
- Case acceptance: The provisional is crucial to functional acceptance of the case as it pertains to occlusal vertical dimension (OVD), guidance, phonetics, and a mutually protected occlusion.
- Esthetics: Provisionalization is the trial phase for the case to assess negative space, color transition, and translucency.
As patients’ expectations elevate, the provisional process becomes an increasingly critical communication tool used by the dental team to evaluate each aspect of the case. For the patient, the provisional "test run" offers the opportunity to comment on the planned final outcome. The provisional phase also allows patients to participate in the case, giving them a true voice in the final outcome.
For the clinician, the wax-up, mock-up, or provisional supplies all the information needed for proper tooth preparation, gingival architecture, as well as any possible limitations of the case, such as orthodontic movement options or bony structures that will influence the final outcome. For the technician, these interim phases of the case offer a roadmap to follow and to communicate changes that may need to be made to meet the level of excellence expected.
The Challenge of Missing Tissue
While all of these aspects make for a successful case, the focus here is to convey the esthetic capabilities of the provisional restoration in the esthetic zone. Restoring teeth with acrylic can have some limitations without taking some extra steps. Also, if any gingival tissue needs restoring, the use of pink composite materials can be added to the acrylic. When a gingival component is added to a case, there is nothing more important than to have a "pink" intraoral blueprint to help guide the technician in the final ceramic stage.
As with any case, photographic communication is always the best starting point for case evaluation. This patient presented with a difficult esthetic challenge (Figure 1 ). As is noticeable in the preoperative photo, the patient’s lip dynamics are frozen in an effort to cover her extreme discomfort with her oral situation. Figure 2, a retracted view, demonstrates the difficult esthetic challenge that the dental team faces in re-creating this young woman’s missing teeth, gingival tissue, and bony arch. In a demanding, esthetics-driven case such as this, there are several challenges to overcome in order to restore her previous oral situation.
The diagnostic wax-up can serve as a guide to fill the voids and create the needed tooth height and width ratio in comparison to the height of the gingival tissue, as well as the papilla’s relationship to the tooth position (Figure 3 and Figure 4). Because the incisal edge position is already established by the natural tooth and emphasized by the Essex appliance, no wax try-in is necessary. The only true evaluation would be in the gingival, and this can and will be adjusted in the final case.
Provisional Fabrication Steps
After fabrication of the wax-up, a putty index is made. Each index serves a purpose, such as tooth position, and a flasking system can also be used for duplication (Figure 5). Duplicating the wax-up allows the technician to reproduce either the wax-up or inject the flask with almost any material to create provisional restorations (Figure 6 and Figure 7). The wax-up can also be scanned and the provisionals fabricated using a CAD/CAM milling or 3-D milling process.
New indexes should be created for evaluation of the cutback and to aid in placement of translucent materials (Figure 8). After the cutback, ceramic stains were mixed with composite thinning liquids and placed, then light-cured into place (Figure 9, Figure 10 and Figure 11). The provisional can be placed back in the flask mold and re-injected with a clear acrylic, or a composite material can be placed back to the incisal index (Figure 12).
Shape and contour of the provisional restorations are key and help to evaluate final restorative outcome. If needed, gingival composites are added and contoured to match the existing gingival (Figure 13). Polish can be achieved with a liquid glaze material or by hand-polishing with slow speed and polishing compounds (Figure 14).
Tooth shading is critical, as capturing some of the nuances in the patient’s natural teeth in the provisional aids in the final ceramic (Figure 15). As with fabricating all provisionals, the purpose should always be to bring the technician closer to the direction of the final case and address some of the more critical esthetic communication challenges. The value of this process is immeasurable and sets the groundwork for the esthetic realities of the final case (Figure 16, Figure 17, Figure 18 and Figure 19).
About the Author
Peter Pizzi, CDT, MDT, FNGS
Owner and Manager
Pizzi Dental Studio Inc
Staten Island, New York