RESTORATIVE CHALLENGE: The patient presented with discolored composite buildups and worn incisors caused by the misaligned lower incisors. The patient felt that her teeth were too short and boxy looking and wanted to get rid of the unattractive brown composites (see Figure 1).
Restorative team: Brad Jones, Professional Dental Arts, Boise, Idaho and Dr. Dennis Klemp, Astoria, Oregon
Treatment plan: The first objectives were to reposition the six lower anterior teeth with braces and improve the height-to-width ratio on teeth #8-9 by using a laser to raise the gingival tissue. Full crowns would then be fabricated out of pressed ceramic, treating teeth #5-12. Authentic porcelain was selected because of its strength, versatility and esthetics.
Case Study: Dr. Klemp sent impressions of the upper and lower arches and pre-operative photographs to the laboratory. Brad Jones fabricated a diagnostic waxup and created the provisionals. At the next appointment, the diagnostic waxup was evaluated, the teeth were prepped and provisionals were placed.
Dr. Klemp took photographs and an impression of the provisionals and sent them to Jones along with a complete esthetic prescription, a master impression, opposing impression, pre-operative models, bite registration, horizontal plane reference, face bow and photographs.
Jones made the appropriate improvements, then formed a silicone putty matrix over the model of the provisionals and quickly placed the matrix in a pressure chamber at 60psi for better adaptation. He used the matrix as a mold to inject wax over the lubricated dies; this injection process accurately reproduces the patient's provisionals. Jones pressed the case using an Authentic BO+ ingot that is similar to a Chromascop O4O or a Vita B1 shade in brightness and color (see Figure 2).
After divesting and fitting, he began the enamel cutback. First, he did a vertical reduction of 0.3mm; the perimeter of this reduction was marked with a red pencil. Then he drew a thin bisecting line through the cutback using an extra fine pencil 0.5mm in from the facial edge. The facial incisal was beveled from this pencil line down approximately 1/3 of the restoration using a contour stone.
He cut a groove into the mesial incisal and distal incisal edges using a knife-edge contour stone that would hold grey-blue stain and porcelain. He used a double-sided diamond disk to cut in the internal lobe formations, and a pointed flame diamond to soften these cuts (see Figure 3).
Jones used the Authentic paste stains as effects. First, he mixed the blue and orange stains to make low-value stains and applied them to the grooves. He used an ivory mixture between white and A1 to highlight a small detail cut in between the mesial and middle lobe of each incisor. Pearl (white dentin) powder was used as an effect to highlight each lobe with a segment of Orange Fluorescent Powder on the middle lobe (see Figure 4) and the effects were baked.
He used Opal powders to fill to full contour. After the effects bake was evaluated, he layered the restorations to full contour using Opal 2 between the lobes and Opal 3 in the mesial incisal and distal incisal grooves (see Figure 5) and baked the restorations again.
Jones formed the shapes and contours paying close attention to the reflective and deflective zones. Once the basic shape was established, he added surface texture and lobe formation. After the surface was rubber wheeled, he cut in the perikymata with a tapered diamond bur, applied a thin consistent layer of Pulse Fluorescent Glaze Paste to the restoration and then air-fired at 750o with a one-minute high temperature hold. To create a natural surface reflection, he reduced the high gloss of the restoration with a knife-edge rubber wheel then used a large felt wheel and diamond paste to increase the luster on the heights of the lobes.
The final restorations were bonded in place, and the patient said her expectations were exceeded (see Figure 6).
Contact information: Jensen Industries is now the exclusive distributor of Authentic porcelain*: call 800-243-2000 or click here to visit the website.
Authentic porcelain was formerly available from Microstar and its dealers.