And the Winner is...Bart Hyde, Hyde Dental Prosthetics

Bart Hyde · Technical · June/July 2014

  • Step 2: Mounting the Casts
    Upon receiving the plaster record bases, it was clear they needed to be adjusted. I trimmed the borders and adjusted a few high spots so the plaster rims fit the casts properly for an accurate mounting.

    It was very important to set the condyles according to the patient’s detailed history: the right was 28 and the left was 30.

    I mounted the models according to the occlusal plane on the Candulor Articulator CA II. This step is very simple with this articulator because the grooves are milled in the incisal pin and its lower element. I used an elastic string around the articulator and putty to line up the base with the occlusal plane.

  • Step 3: Model Analysis

  • I determined the necessary information to properly set up the case with the Gerber concept:
    * Static lines: these parameters indicate where the teeth can be functionally placed according to the anatomy of the maxillary and mandible bone structures.
    * Stop line: Having any occlusion posterior to the stop line will cause the denture to slide anteriorly and dislodge during chewing—also known as Christensen’s Phenomenon—so you want to avoid this scenario.
    * Lowest portion of the posterior ridge: ideally, the first molar should be centered on the lowest part of the surveyed ridge. This centers maximum biting force in this area, assisting in seating the mandibular denture while in function.
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    Step 4: Preserving Information
    To retain the esthetic information from the plaster bite rims, I used lab putty to preserve length, midline and buccal/labial fullness. I also transferred the high lip line from the bite rim to the land area of the cast with a compass and recorded the measurement on the cast. The putty enabled me to arrange the anterior teeth to the proper facial contour and midline according to record bases.

  • Step 5: Sub-Frame
    To add rigidity and reinforce the lower implant-retained denture, I constructed a cast cobalt-chrome frame that was blasted, prepped and opaqued to prevent any metal show-through.
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    Step 6: Anterior Setup
    I prepared the baseplates on the casts to begin the setup process. Using the Candulor PhysioStar® NFC+ teeth provided, I started with the upper anteriors, placing them according to my vision and information preserved from the plaster bite rims. Using carbide burs and rubber polishing wheels in a handpiece, I carefully added incisal detail to replicate age-appropriate incisal wear. Next, I set the lower anterior to create a natural arrangement that complemented the upper arrangement while having good incisal contacts when in protrusive.

  • Step 7: Posterior Setup According to Gerber
    I used the Gerber principles of centering the first molar within the parameters determined by my model analysis and the lingualized “mortar and pestle” concept, a design specific to the CondyloformII NFC.

    You’ll notice on the left side, I set the second molar fully functional as it was anterior to the stop line and the first molar was very well centered on the lowest part of the surveyed ridge. On the right side, the second molar was posterior to the stop line and was set out of occlusion while the first molar was centered on the lowest part of the ridge.

    Another option on the right side would have been to leave out the second molar but from my experience, it’s better for the psyche of the patient to make both sides symmetrical.

  • Step 8: Detailed Waxup

  • My goal is always to create an anatomical waxup with the contours exactly where I want them, minimizing the need for grinding. I also wanted to maximize the muscle grip by creating the appropriate facial and buccal contours onto the facial and buccal surfaces.

  • I thought it was also a nice detail to duplicate the patient’s natural rugae in the palate of the denture. To do this, I made an impression of the rugae area of the cast with lab putty, flowed wax into the impression, peeled the wax out and applied it to the waxup.
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    Step 9: Processing
    I sealed the casts to the processing models, invested, washed out and applied separator to all exposed stone. Upon cooling, I used Candulor's Aesthetic Color Set Easy to apply the intrinsic coloring to the denture base. Then I press packed the case using a blend of base resins to achieve the shades, veins and desired natural blending effects.

  • Step 10: Tooth Modification/Characterization
    I characterized the denture teeth using Ivoclar Vivadent’s Telio Lab Kit. First, I did the lingual cutbacks and prepped the surfaces with aluminum oxide blasting media following the directions on the kit. I used white to add some internal details and nuances found in natural teeth. After curing the stains, I backfilled the area with incisal shade to add translucency to the teeth and achieve a more lifelike appearance. I repeated these steps on the upper and lower anteriors.

  • For the external staining, I used the same stains to add cracks and applied cervical stains. I smoothed out the backfilled areas with a carbide bur, followed by a handpiece with rubber points and wheels, and then polished to a high shine with appropriate compounds.

  • Most patients’ dentition has some form of previous dental work—really, who in their 60s doesn’t have an amalgam or stain on their natural teeth?—so I added a very subtle amalgam stain on the mesial of #12. This subtle detail brings an ordinary denture to life.

  • Step 11: Polishing
    Due to the detail of the final waxup, very little finishing was required. I fine-tuned the occlusal details to achieve proper balance through excursions and then polished the case with pumice and rouge to a very high shine and fitted it to the master cast.

About The Author
Bart Hyde

Works at Hyde Dental Prosthetics

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