How to Combine All-Ceramic Anterior and PFM Posterior Restorations For Seamless Esthetics
Posted Feb 10, 2012 in Technical
The patient was unhappy with her existing restorations on teeth #3-14 because of the dark outline at the margins, tissue recession and the shape of the teeth. See Figure 1
The restoring dentist, Steven Hart, DMD, Chapel Hill, NC, and I recommended replacing the existing restorations with IPS e.max crowns on #6, 7 and 8; a three-unit IPS e.max bridge on #9, 10 and 11; and IPS d.SIGN PFMs with porcelain labial margins on #3, 4, 5, 12, 13 and 14.
Dr. Hart and I selected these two Ivoclar Vivadent products because they enable seamless integration of all-ceramic and ceramo-metal restorations and would satisfy her functional requirements and esthetic expectations. IPS e.max Press lithium disilicate has a flexural strength of 400 MPa and excellent optical properties, making it ideal for esthetically challenging cases and matching PFMs. IPS d.SIGN is a fluorapatite leucite glass-ceramic that offers firing and shade stability after several cycles, enamel-like abrasion behavior and well-balanced chroma and brightness that mimic natural tooth structure. See Figure 2 and Figure 3
Because the patient was so unhappy with the esthetics of her existing anterior restorations, I created this diagnostic waxup using tooth-colored wax to show her our proposed treatment plan. We divided the restorative process--completing the anterior treatment and then replacing the posterior restorations--so we could address her esthetic concerns more quickly.
Fabricating the Anterior Restorations
The existing anterior restorations were removed, revealing extensive decay and discoloration. See Figure 4
Dr. Hart selected the stump shade that matched and blended with the patient's prepared tooth shade. See Figure 5
Based on the diagnostic waxup, Dr. Hart made these provisional restorations to verify the length, lip support, phonetics and function. See Figure 6
Using the provisional as a guide, I waxed up the six anteriors and cut back the facial for layering.
I sprued, invested, burned out and pressed the restorations using the proper shade of IPS e.max Press. After devesting the pressed restorations, I placed them in Ivoclar Vivadent's Invex liquid to eliminate the surface reaction layer. I cut the restorations from the sprues, scrutinized them against the model and cut back the labial surface to enable shading to create the desired color blend. See Figure 7
I pressed with LT A1. Next, I applied Impulse EO5 at the cervical and proximal areas of the restorations, sprinkled them with A-1 DD and baked them.
I built up the first layer by applying a 1:1 mixture of A-1/OE3 in the facial and a 1:1 mixture of A-1/A-2 in the cervical and then baked the buildup.
After I established the final contour, I glazed the restorations, verified the fit on the solid model, polished them with a rubber wheel and diamond polishing paste, and delivered them to the dentist. A final check was performed and another polish completed to ensure proper luster. See Figure 10, Figure 11, and Figure 12
Fabricating the Posterior Restorations
I fabricated the posterior PFMs with IPS d.SIGN porcelain. Using .005 Williams platinum foil spot welded to the labial framework, I applied a margin material in a thin layer and fired the restorations. Using a porcelain stratification technique, I built up the restorations to full contour using dentin layers of different values and translucencies and then characterized them using intensive materials. I used the DeVreugd Occlusal Compass to establish the posterior morphology.
The PFM restorations were fired and then checked on the master model. After I adjusted the form and contours, I baked the restorations a second time and completed the final contouring and surface texturing using diamond burs and green stones.
Before the final polish of the porcelain, I removed the platinum foil and polished the lingual metal collar. The case was then delivered to the dentist.
Occlusal view of the completed restorations. The results demonstrate the seamless blending of anterior all-ceramic units and posterior PFMs. See Figure 13
Russel DeVreugd is the Owner of DeVreugd Dental Laboratory and DeVreugd Dental Seminars (www.devreugddental.com and www.idseminars.com respectively), an international consultant and lecturer in the field of fixed restorative dentistry. On the Dental Laboratory Advisory Committee at Durham Technical Community College, he also has served as a consultant/lecturer for the Department of Biologic and Material Science at the University of Michigan School of Dentistry and the undergraduate and graduate prosthodontic programs at the University of California School of Dentistry. DeVreugd has presented courses on occlusion, contour, color and anterior esthetics throughout North America and Europe and is a contributing author to Science and Practice of Occlusion and Quintessence of Dental Technology.
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