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Inside Dentistry
January 2016
Volume 12, Issue 1

The authors’ plan was to replace the eight maxillary restorations with the Authentic® pressable ceramic system (Jensen Dental, www.jensendental.com) using the Authentic® B00+ ingot (Jensen Dental) for all-ceramic crowns for teeth Nos. 4 through 7 and Nos. 10 through 13, veneers for teeth Nos. 8 and 9, and two Authentic® Pressable to Galileo high noble (Jensen Dental) porcelain-fused-to-metal (PFM) crowns for teeth Nos. 3 and 14. Twelve mandibular teeth were prepared and the same porcelain and PFM system and ingot selection was utilized. Four all-ceramic crowns (teeth Nos. 20, 21, 28, and 29), two PFMs (teeth Nos. 19 and 30), and six veneers (teeth Nos. 22 through 27) were treatment planned to obtain a more uniform color appearance. The Authentic pressable system was selected due to its strength, superior optical properties, and conservative prep design. According to the manufacturer, Authentic is the strongest pressable ceramic material in the leucite-reinforced pressable category and offers 58 different fluorescent pressable ingots in a range of opacities, which increase vitality to resemble the natural dentition in all lighting sources.9

Clinical Protocol

After an extensive diagnosis of this patient’s functional and esthetic needs, the decision was made to first perform crown lengthening on teeth Nos. 5 and 12 and then treat the mandibular teeth. Restoring the mandibular teeth prior to the maxillary teeth would allow an opportunity to establish the proper plane of occlusion and curve of Spee by utilizing the Wynne 2000 adapter for the SAM® 3 articulator (Great Lakes Orthodontics, www.greatlakesortho.com) (Figure 6). This occlusal plane analyzer identifies on the flag atop the articulator the intersection of two 4-in arcs. One arc’s center originates at the incisal tip of the mandibular canine, with the other arc’s center originating from the most distal cusp of the last mandibular molar. From the point of intersection of the two 4-in arcs, a new 4-in arc’s center will touch the cusp tips of the premolars and molars, indicating any necessary shortening or lengthening of cusps to form the proper curve of Spee (Figure 7). This necessary step allows harmony to exist between the anterior teeth and condylar guidance by eliminating excursive interferences and obtaining a more predictable occlusal relationship.10

A properly waxed mandibular model was used to create an axial reduction matrix for the mandibular arch, as it is easy to use and provides the proper form for the preparation at different heights. The preparation of the mandibular arch required 0.8 mm of facial reduction and 1.5 mm of incisal reduction of the six anterior teeth. A 0.5-mm depth cutting diamond (Maxima Diamond No. 9000-7136, Henry Schein Inc., www.henryschein.com) was used, followed by a 0.3-mm depth cutting diamond (Maxima Diamond No. 9000-7135, Henry Schein) for a total of 0.8 mm of facial reduction. Each depth cut was identified with an indelible marker to ensure the exact amount of tooth structure was removed with the round-ended diamond No. 112-5161 (Henry Schein). As a 1.5-mm incisal reduction was desired in this case, the authors sank a 0.75-mm diameter diamond bur twice its diameter to get the desired reduction. A diamond shank (8878K.31, Brasseler USA, www.brasselerusa.com) was utilized to clear the contact areas and smooth all external line angles. By preparing the teeth with cleared contacts, several advantages are gained:11

• Technician is provided with control over placing and correcting misaligned midlines.
• Alterations in color can be made in this area to mimic natural teeth.
• Lingual margin is placed in a free cleansing area.
• Retention form is increased.

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