To provide a spacer on the custom abutments and allow removal of the provisionals from the abutments, Rubber Sep (George Taub Products & Fusion) is brushed onto the abutments and allowed to air dry (Figure 15). It is recommended that several coats be applied to ensure ease of removal of the processed provisionals from the abutments. Syringes in the selected dentin and enamel shades are placed into the warming unit and allowed to become flowable.
The selected dentin shade is expressed over the abutments and allowed to cool to room temperature (Figure 16). At room temperature the resin composite becomes “wax-like” in its handling. Some anatomical shaping can be performed at this point, using a clean composite or wax carving instrument. The selected enamel shade is then expressed from the warmed syringe over the Radica already on the abutments (Figure 17). Before the enamel shaded Radica has cooled, the casts are articulated to develop the occlusal contact points based on the opposing dentition (Figure 18). A scalpel is used to demarcate the division of the units using a mark on the cast as a guide (Figure 19). As the resin is wax-like in handling at this phase, it can be easily carved and shaped.
The provisionals may be removed from the abutments, and the Rubber Sep is peeled from inside the Radica resin. A scalpel is then used to carve the gingival embrasure area between the units and develop the appearance of individual teeth (Figure 20). Should additional material be needed, it can be added from a warm syringe and the material blended with an electric spatula (Figure 21).
Should a void be present in the uncured resin, the electric spatula is utilized to add material or flow surrounding material into the area. The spatula is also utilized to assist in blending the dentin and enamel shades to develop more natural effects. It is not advised to use an instrument heated in a flame, as this will introduce contaminants (soot) into the material before processing.
The anatomy is created and adjusted, and the provisionals are ready for processing (Figure 22). Radica VLC sealer is brushed over the finished provisional resin prior to processing (Figure 23). Sealer application eliminates any oxygen inhibited layer on the surface of the provisional and provides a glazed final surface. Should supplemental staining be desired, Radica stain powders are blended with sealer and brushed onto the surface. As these stains are very intense in color saturation, only a few particles are necessary to tint the sealer.
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Figure 21. Additional resin may be added to the uncured provisional using an electric spatula. |
Figure 22. Basic anatomy and form for the provisionals is created in the uncured resin. |
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Figure 23. Sealing resin is painted over the uncured provisional to eliminate an oxygen inhibited layer following curing. |
Figure 24. The finished provisionals after curing, finalization of the anatomy and polishing. |
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Figure 25. Finished provisional crowns in articulation on the casts. |
Figure 26. Intraoral view of the Radica provisionals. |
The Radica provisional is placed into an appropriate light-curing unit (Triad 2000, Enterra, or Eclipse light-cure units [DENTSPLY Prosthetics]) and polymerization is completed.
Following removal of the processed provisional, additional shaping may be performed with diamonds (DENTSPLY Caulk) and a Sepaflex diamond disk (DENTSPLY Prosthetics) to achieve the desired final form. Polishing is similar to composite resin and can be accomplished with finishing disks (Fini [Pentron Clinical Technologies]) and soft felt wheels (DENTSPLY Prosthetics). Following polishing, another coat of the Radica sealer is applied and light-cured. The restoration is now ready for delivery with the custom abutments (Figures 24 to 26).
CONCLUSION
In-office custom implant abutments can be easily and cost effectively fabricated using the Abutment Preparation Burs Kit 4475. This allows the practitioner to provide implant-fixed prosthetics within the financial means of patients and within the boundaries of their insurance plans. Although not a solution to all implant-fixed prosthetic situations, this can be used in many cases when drastic changes in angulation are not required; specifically, in the posterior regions.
When the final prosthetics cannot be delivered at the time the implant abutments are being placed, long-term provisionalization may be indicated. Fabrication of these long-term provisionals, whether in-office or by a laboratory, will minimize chairside time and provide a durable alternative to other commonly used provisional materials. Radica allows the fabrication of these implant provisionals with the need for minimal equipment, providing durable, multishaded restorations that rival the final prosthetics aesthetically.