Restorative challenge: A male in his 20's presented with TMJ symptoms of excessive occlusal wear, headaches and clicking in the Temporal Mandibular Joints. After a thorough neuromuscular examination, Dr. Liem established a new vertical position and fitted the patient for a series of orthotic appliances. This habitually re-established a comfortable vertical position and the patient's clicking and headaches subsided. Fixed restorations were required to stabilize and maintain the new vertical position and prevent further occlusal wear and destruction.
Restorative team: James Neuber, RDT, Ocean Ceramics Ltd., Coquitlam, British Columbia and Dr. Edmund Liem, Chilliwack, British Columbia
Treatment plan: The dental team decided to fabricate and bond Ti-Press onlays onto the six mandibular posteriors. This conservative approach would preserve the maximum amount of tooth structure while maintaining the cemento-enamel junction, controlling vertical forces internally within the ceramic and maximizing esthetics. The press-to-metal technique would be used because the extra strength of the metal substructure was required. The Ti-Press onlays would be fabricated with Talladium's Luminesse Pressable Porcelain pressed to Tilite® Luminite Press Alloy, which caused significantly less wear to enamel than glazed feldspathic porcelain during wear tests.*
Case study: Dr. Liem prepped the teeth supragingivally in order to conserve tooth structure (see Figure 1). Impressions were taken and sent to the lab. The master casts were mounted using the silicon bite registration on the AccuLiner® articulator to establish the exact vertical height.
James Neuber, RDT, designed the metal copings on the occlusal surface to act as a rebar-type support for the patient's aggressive mastication. He then metal finished, degassed and opaqued them to the prescribed Vita® shade**. Internal fluorescent orange modifier was applied to the opaqued surface to add warmth and chroma within the occlusal surface.
Using Talladium's Pressable Wax, Neuber waxed the posteriors to full contour (see Figure 2). The units were invested and pressed using Talladium's Galaxy Universal Investment. Once the units were divested with glass beads at a recommended 30psi, they were placed back onto the model with no internal fitting needed (see Figure 3). Enamels were layered onto the pressed cores for added light refraction (see Figures 4 and 5). Finally, the units were internally acid etched in a 9% hydrofluoric etching gel in order to facilitate the bonding procedure.
The bonding agent adheres to the ceramic as well as the Tilite® Alloy for increased strength; attempting to bond to a gold-based alloy would have compromised the internal strength. Dr. Liem had no adjustments to make and the patient was very satisfied with the esthetic results as well as the comfort of the vertical repositioning (see Figure 6).
*In Vitro Assessment of Enamel Wear When Opposed by Various Ceramic Materials. S. SHAH, G.R. GOLDSTEIN, E. CLARK, and E.L. HITTLEMAN, New York University, USA, New York University College of Dentistry, USA
**Registered trademark of VITA Zahnfabrik