PDF Download - Glidewell Dental Labs

Production Workflow
A single package that includes laboratory services helps to
maximize clinical efficiency, reduce chair time and minimize
remakes and chairside adjustments. The advantages of this
treatment protocol are best explained by following a Screw-
Retained Hybrid Denture (Fig. 1) as it moves through the
various phases of laboratory production.
All-in-One Package
Screw-Retained Hybrid Dentures are typically indicated
for edentulous patients desiring a replacement for removable
prostheses. The Inclusive Tooth Replacement System
package simplifies tray setup and eliminates the hassle of
selecting components and arranging laboratory services as
doctors move from one phase of treatment to the next. A
complete case includes:
• 6 tapered implants
• Final surgical drill
• 6 titanium healing abutments
• 6 impression copings
• 6 analogs
• Model work
• Implant verification jig
• CAD/CAM milled titanium bar
• Final denture with premium denture teeth
The Process
Step 1: Fabrication of Implant Verification Jig
and Custom Tray
After placement of the implants and completion of the
healing phase, the laboratory receives the preliminary
impression taken by the doctor. A preliminary cast is poured
from this implant-level impression, which, along with the
impression copings it contains, conveys the patient’s tissue
level, gingival contours and position of the implants to the
laboratory. The processing of the preliminary impression
for overdentures is efficient and predictable because cases
are planned from the beginning with the same interfacing
components and restorative-driven approach in mind.
Based on the preliminary impression, the laboratory
technician fabricates the implant verification jig and
custom impression tray. The verification jig is sectioned
and numbered on the preliminary model (Fig. 2) — each
section containing a non-engaging titanium cylinder — and
sent to the clinician along with the custom impression tray
so the final impression can be made. To maximize clinical
flexibility and efficiency, the laboratory will fabricate the
bite block at this stage if requested.
Step 2: Fabrication of Master Cast and Bite Block
Next, the laboratory fabricates the master cast and bite
block. Note that the final impression contains the implant
verification jig, which conveys the exact orientation of the
implants to the laboratory and ensures a precise fit of the
CAD/CAM milled titanium framework that will be designed
and milled after denture try-in and approval. The master
cast incorporates implant analogs in the same orientation
as the implants placed by the surgeon. The bite block is
fabricated onto the master cast (Fig. 3) and articulated
with the opposing cast. In cases where the bite block was
distributed with the implant verification jig, the base plate
is adjusted to fit the master cast. The laboratory technician
incorporates two screw-retained temporary cylinders that
will be used to retain the bite block when jaw relations are
recorded during the next clinical appointment.
Step 3: Articulation of Casts and Setting of
Denture Teeth in Wax
Once the laboratory receives the jaw relation records,
opposing impression, bite registration and working cast,
the models are articulated and the technician carefully sets
the premium denture teeth according to the instructions
provided by the doctor in the prescription (Fig. 4). The
mounted denture setup is sent to the doctor for try-in and
evaluation of centric relation, VDO, esthetics, phonetics,
tooth arrangement, shade and occlusion.
Step 4: Fabrication of Titanium Framework
Once the denture setup is approved, the model and setup
are scanned, and the titanium bar is fabricated. The titanium
framework is designed by the lab technician using CAD/CAM
technology to achieve a precise fit of less than 20 microns
(Fig. 5). The bar is then milled and the denture setup is
transferred onto the framework before being sent to
the doctor for final try-in. By following a predictable,
restorative-driven workflow, the laboratory produces a
well-fitting titanium bar that typically exhibits a passive fit
upon initial seating, minimizing remakes and adjustments.
This simplifies and makes for a smoother clinical process
that enhances the chair time experience and maximizes the
restorative result for the patient.
Step 5: Processing of Acrylic and Denture Teeth
to the Framework
After a final try-in and approval of the combination titanium
bar and transfer setup, the laboratory completes the final
denture by processing the framework and setup into acrylic
(Figs. 6–8). The resulting final prosthesis is accurate, esthetic
74
– www.inclusivemagazine.com –