 |
|
| Adjustable Box
Precision
Intracoronal Instructions |
Screw adjustable retention intracoronal precision
attachment for effective retention of removable partial dentures.
Advantages:
- Gingival bevel on the male for easy patient insertion
and removal--reduces wear potential.
- Retention is fully and easily adjustable by simply
tightening or loosening the screw
- Female may be cast against with precious or semi
precious alloy for easy fabrication.
- Vertical height may be reduced for short or close bite
situations.
- Excellent external wall contact for guide plane
stability.
- Male may be connected to the cast frame by acrylic
resin, composite resin, bonding, or solder. Very easy techniques.
- Easy technique to incorporate male housing into cast
chrome cobalt frame.
- System allows for conversion of fixed bridge to a
removable partial denture if distal abutments are lost.
Be sure that the retaining abutments are large enough that
an adequate internal box preparation may be completed to receive the attachment
female.
The Adjustable Box is a rigid or non-moving connector.
Multiple strong abutments and splinting is recommended, as forces are therefore directed
to the abutments
Laboratory Procedures
Crown and Bridge
For bilateral insertion and free-end dentures cast transversal connections such as plates in the upper, sublingual connectors in the lower jaw are used. It is important that these constructions are absolutely rigid (no springiness).
1. Determine the path of insertion of the
removable prosthesis using a surveyor. A double tilt is recommended. In order to prevent overcontours on the crown, a box must be prepared in the abutment into which the female part of the slide attachment can be placed. The box preparation should be larger than the width and depth of the female part of the attachment (0.6 x 0.2 mm).
2. Wax the patterns for full coverage abutment
crowns.
| 3. If a lingual bracing arm and/or mesial rest is to
be incorporated into the removable prosthesis, prepare the recesses into the wax
abutment patterns . |
Most slide attachments used for partial dentures and prospectively planned bridgework must be protected against overload caused by leverage.
This is achieved by constructing a brace support (milled lingual section of primary crown with cast secondary part). |
|
|
1 |
2 |
| 4. When using the Box attachment, cast with only precious
or semi-precious alloys.
5. Thoroughly
clean the female and remove any grease residue on the female with a steam
cleaner (FIG 1). 6. Position the female(s) in the
wax abutment pattern(s) with the paralleling mandrel (FIG 2). The female
attachments must be vertically parallel, in proper crown contour, and over
the crest of the ridge.
The attachment female(s) also must be parallel to the
path of insertion and as close as possible to the long axis of the abutment. |
|
3 |
4 |
| 7. Be sure to
completely wax to the female. If the abutment crown is to be porcelain
fused to metal, the porcelain needs to be fused to the cast alloy, not the
alloy of the attachment female (FIG 3).
8. With a fine instrument, make a groove between the wax and the
attachment female. This will prevent casting alloy flash on or in the
female attachment (FIG 4). You may wish to paint the attachment female
with Liquid Colloidal Graphite to act
as an anti-flux. |
|
5
|
| 9. Do not use wax conditioner or
debubblizer as this will cause casting alloy flash on the attachment female
(FIG 5).
10. Accurately sprue and invest the
patterns (Preci Roto System).
Do not exceed the female melting temperature of 1400-1490°C |
|
7 |
8 |
| 11. Carefully devest
the casting and clean in an ultrasonic cleaner. Do NOT sandblast to
remove investment from the female as this will oversize the inside of the
attachment female. Shell blasting, brass or fiberglass pencils may be
used to remove investment from the female (FIG 7).
12. The male attachment should now be checked for
accurate fit with the female. Liquid Colloidal Graphite may be painted
on the male attachment--and the male attachment repeatedly inserted and
removed from the female to remove any minor discrepancies and assure a
proper fit (FIG 8). |
13. The completed abutment restorations are returned
to the dentist for patient try in. The abutment restorations are picked up
in an accurate new master impression in the material of choice and returned to
the laboratory.
14. Prepare a new master cast.
Cast
Frame and Acrylic (Removable)
|
9 |
10 |
| 16. Place the metal male into
the female on the master cast. Block out all undercuts (FIG 9), and
prepare model for duplication and preparation of refractory cast.
17. Use an accurate duplicating material and pour
up refractory cast. (FIG 10).
18. Wax, cast and finish the frame, leaving space for the male inside the framework. |
Laboratory
Direct Bonding of the Attachment Male to the Cast Frame
|
11 |
12 |
| 19. Sandblast the
framework receptacle and the retention area of the attachment male with
clean aluminum oxide (FIG 11). Clean the sandblasted areas with a
steam cleaner or distilled water in an ultrasonic cleaner, or clean with a
stiff tooth brush and water. 20. Seat the
male attachment into the female on the master cast. Block out openings
and undercuts with latex rubber or silicone (rubber sep) (FIG
12).
The walls must have a minimal thickness of 0.5 mm in order to avoid a deformation of the female part.
|
|
13 |
21. Mix a small amount of CEKA SITE
(anaerobic composite bonding resin that sets in the absence of air)
following instructions. Apply CEKA SITE to the framework receptacle
and the retention area of the attachment male (FIG
13). Seat cast
frame over the attachment male on the master cast and allow a full 5 minutes
for the CEKA SITE to set. Any excess CEKA SITE may be cleaned away
with a brush after removal of the cast frame from the master cast.
Another alternative is to connect the precious metal attachment male to the
cast frame with solder. |
22. If an occlusal rim technique is to be utilized,
complete at this time.
23. Complete the wax set up on the cast frame.
Send to the dentist for try in and approval.
24. Process and finish the acrylic resin base in the
technique of choice. The male attachment should be covered with Vaseline®
or rubber prior to processing. This will protect it from any flash or
excess acrylic resin.
Bonding
or Resin Pick Up in the Laboratory or Chairside by the Dentist
The acrylic resin is processed and finished on the cast
frame without the attachment male bonded or soldered into the cast frame.
|
12 |
13 |
| The cast frame receptacle
and retention area of the attachment male are sandblasted with clean
aluminum oxide (FIG 12). Clean the sandblasted areas with a steam
cleaner or distilled water in an ultrasonic cleaner, or a clean stiff
toothbrush and water. The attachment male is
seated in the female on the master cast for laboratory bonding or resin pick
up. The attachment male is seated in the female in the mouth for
dentist chairside bonding or pick up. Block out the openings and
undercuts with latex rubber or silicone (rubber sep) (FIG 13). |
|
14 |
The attachment male is now bonded into
the prosthesis with CEKA SITE as outlined in step #22. An alternative
would be to pick up the attachment male using self cure (FIG
14). |
T0092.REV.00
|
