How to Match Central Incisors Using a Jacket Crown and Laminate Veneer Made With Noritake EX-3 Porcelain

Alek Aronin · Technical · Nov 2013

  • Restorative Problem

    A 23-year-old female sustained a facial injury that resulted in tooth #9* requiring endodontic treatment and a subsequent full coverage restoration. A pressable crown with external stain was placed but the patient was unhappy with the esthetics and requested further treatment.

    Dr. Efim Fichman, DDS, North York, Ontario, Canada and I decided to replace the existing crown on tooth #9 with a porcelain jacket crown and fabricate a porcelain veneer on the vital, non-restored tooth #8**. Note the especially translucent nature of the patient's maxillary incisors, making the case even more technically challenging.

    *Tooth #21 according to FDI Notation.
    **Tooth #11 according to FDI Notation.

  • Step 1: Using the VITA 3D-Master® shade guide, Dr. Fichman selected 1M1 for the shade. He also used the Gumy® Shade Indicator from Shofu that's designed to be used in conjunction with a conventional shade guide and takes into account the contrasting effects of the patient's gingiva when determining proper shade. When the proper shade was determined, I used Noritake Value Shade (NV) 1110B.

  • Step 2: When the existing crown on #9 was removed, the remaining tooth structure was relatively minimal in height and had a discolored root. The veneer preparation on #8 was conservative with only slightly discolored remaining tooth structure.

  • Step 3: During the crown fabrication, I used a wash layer of Noritake Creamy White Luster Porcelain to mask the discoloration on tooth #9. To restore the shape of the tooth, I used a thin layer of Opacious Body White. Using a thin layer of material was critical to ensure that I changed the value of the discolored tooth without blocking light transmission.

  • Step 4: For the buildup, I used Noritake EX-3 Body 1110B, Enamel E1 and Noritake EX-3 Luster Porcelain Aqua Blue 2.

  • Step 5: I baked the crowns and prepared them for internal live application with accurate incisal edge alignment in place.

  • Step 6: Next, the internal stains were applied.

  • Step 7: To prevent uneven shrinkage during the subsequent baking of the veneer and crown, I applied Noritake EX-3 LF (low fusing) Press Lusters—including LT1, Creamy Enamel, LT0, Incisal Aureola and LT-Yellow—on the internal live stain prior to baking. Shrinkage during baking is always greater on unsupported porcelain; if materials other than the low-fusing lusters were applied, the jacket crown would be subject to greater overall shrinkage than the veneer which would result in the entire internal canvas (such as crack lines and mamelons) being repositioned gingivally from the desired levels. EX-3 LF porcelain bakes at 760°C, which is 170°C less than the porcelain used during the buildup of the restoration (see Step 4). Here are the final baked porcelain restorations on the model.

  • Step 8: During the try-in procedure, the restorations appear to be lower in value relative to the neighboring teeth. This visual outcome was due, in part, to the dehydration process on the laterals and canines that makes the enamel appear temporarily whiter. In addition, the use of a "clear" material for the try-in paste contributed to the overall temporary contrast in value.

    In most cases, a critical point to consider is the undesirable and permanent contrast in value that can occur between bonded porcelain restorations fabricated with minimal thickness (0.3mm-0.5mm) and their neighboring, non-restored teeth. In my experience, when a clear material is used for bonding anterior porcelain restorations, it almost always causes a permanent reduction in the overall value of the final units. Using a clear material for bonding is of no significant esthetic consequence for posterior restorations but for anterior restorations, using a chromatic material (dentin shade) is always preferable.

  • Step 9: Dr. Fichman etched only the enamel of tooth #8, thereby increasing the micromechanical retention. For bonding to the composite post buildup of tooth #9, he applied a silane to create a chemical connection and then used Kuraray’s Clearfil Ceramic Primer followed by Clearfil SE Bond. For the final cementation of both restorations, he applied Clearfil Majesty ES 2 White Dentin light-cured composite resin, resulting in optimal value of the final restorations.

  • Final Result
    The patient is happy with the esthetics.