Figure 6: Final DuraTemps provisional restoration
Lab-processed versus direct provisionals
When is it advantageous to use lab-processed provisionals, and when is the direct technique the best solution?
Direct technique—For anterior veneer cases, direct is the popular choice with many clinicians. The preferred method seems to be using a putty impression with a polyvinyl siloxane wash that has been taken of a quality wax-up, then curing a bis-acryl in the mouth using the putty matrix. These typically are not cemented, but rather rely on material shrinkage and undercuts to hold them in place. Cleanup is done in the mouth without removal of the provisionals.
Lab-processed provisionals—Once a case gets more complicated (involving restorations beyond the anteriors or including full crowns in the treatment), indirect lab-processed provisionals become the standard. Some of the advantageous traits of lab-processed DuraTemps are as follows:
- Proper gingival contour
- No staining due to their smooth, glazed surfaces
- Accurate fit
- Patient’s testing of VDO
- Approximate shade
- Desired texture and shapes
- Stronger than chairside temps
- Can have additional strengtheners added, such as wire, metal mesh, or fiber mesh
- Properly proportioned
- Occlusal and functional design
It is essential to make all smile-design decisions with the patient before wax-up or provisional fabrication. Spending this time on the first records-collection appointment gives dentists and lab technicians the tools required to create provisionals that will be the working template for the final ceramics.
Fabrication procedures
The following are key aspects of DuraTemps fabrication procedures:
- DuraTemps provisionals are typically fabricated from pre-op models.
- The prescribed teeth are reduced 1 mm on all surfaces of the model in the lab.
- The tissue sites are shaped for dentists’ prescribed results.
- Reduction allows dentists to seat and reline easily in the mouth after preparation.
- DuraTemps are methyl methacrylate-based and require a cold-cure acrylic to reline.
Chairside procedures for seating lab-fabricated provisionals
Follow these steps to ensure success with DuraTemps:
- Prepare teeth, pack cord, and control bleeding.
- Try-in the DuraTemps to verify passive seating and estimate that the occlusion and vertical dimension are correct.
- After try-in, clean DuraTemps and brush the monomer on the inside of temps.
- Using petroleum jelly, paint the exterior of DuraTemps and the area 1 mm away from the margins, which will prevent the reline material from sticking to the
DuraTemps surfaces.
- Mix acrylic and fill provisional abutments 3/4 full. Wait until acrylic has a slightly dull gloss, then seat in position in the mouth (figures 3 and 4).
- Test acrylic for stiff rubbery texture and remove. Do not allow to cure in mouth fully.
- Remove the temps from the preps while curing.
- Clean away flash and finish margins. Use soft rubber wheels or fine acrylic carbide, then polish marginal areas with a fine flower of pumice (figure 5).
- Polish restorations with pumice and acrylic polishing paste, and then use a light-cured glaze such as Palaseal (Kulzer).
- Use the temporary cement of your choice. We recommend noneugenol material if you are bonding final restorations (figure 6).
- If needed, you may reglaze the surfaces of DuraTemps with Palaseal, Luxaglaze (DMG America), or a similar light-cured glaze.
More information
For more information on DuraTemps and Burbank Dental Lab, visit burbankdental.com/products/duratemps.
Reference
1. Donovan TE, Cho GC. Diagnostic provisional restorations in restorative dentistry: the blueprint for success. J Can Dent Assoc. 1999;65(5):272-275.