TIPS

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READERS

2. Make an irreversible hydrocolloid (alginate) impression (Fig. 2), ask the patient to hold the tip of the tongue in contact with the soft palate while the material sets. 3. Fill the tongue space of the alginate impression with fast-setting plaster and pour the dental stone cast as soon as the plaster sets. The plaster should be coated with a separating medium. 4. After the stone sets, recover the cast and trim it in the usual manner (Fig. 3). Reprint

requests to:

DR. ALFREDOJ. FERNANDEZ ASSISTANTCHIEF, DENTAL (160) DVA OUTPATIENTCLINIC 2090 KENNY RD. COLUMBUS,OH 43221

Fig. 3. Stone cast recovered and trimmed.

Duplication fabrication Rhoda

F. Jacob,

of interim DDS,

speech aid for definitive

impression

tray

MSa

The University of Texas MD Anderson Cancer Center, Houston, Tex. Most soft palate resection patients wear an interim prosthesis that has been modified for optimum function during healing of the surgical site. The described technique duplicates the interim prosthesis to fabricate a wax final impression tray attached to the definitive prosthesis framework or denture base. Clinical and laboratory time is reduced while maintaining patient satisfaction achieved with the existing prosthesis. TECHNIQUE 1. Make an irreversible hydrocolloid impression of the intaglio surface of the interim prosthesis, including the hard palate and the functional nasopharyngeal portion of the speech aid. 2. Seat the definitive framework or final processed denture base on the irreversible hydrocolloid impression for “best fit.” 3. Drop molten baseplate wax (Tru Wax, Dentsply Intl., Inc., York, Pa.) into the impression of the speech aid and onto the framework retentive loops. For a complete denture, extend the wax onto the polished surface of the denture base. Cool the wax with cold water (Fig. 1). 4. Relieve the borders of the wax tray approximately 3 mm on the nasopharyngeal side to allow space for impression material. Quickly check for overextension of the tray by using a tissue conditioning material (Softone, Harry J. Bosworth Co., Skokie, Ill.) over the entire surface of the tray. Seat the prosthesis in the mouth and have the patient activate the palatopharyngeal complex.

aAssociateProfessor of Dental Oncology. lQ14m3771 THE

JOURNAL

OF PROSTHETIC

DENTISTRY

Fig. 1. The definitive framework is seated on the irreversible hydrocolloid impression, and molten baseplate wax is dripped into the speech aid.

5. Relieve the wax in pressure areas denoted by thin or absent impression material. 6. Place tissue conditioning material (Trusoft, Harry J. Bosworth Co.) for a final impression. For large defects, incremental placement of material is necessary to avoid wiping away the material on insertion of the prosthesis. 561

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READERS

SUMMARY

Fig. 2. The wax tray extends through a patient’s soft palate defect and is ready for the final impression material.

After functional movements, verify that there is tissue contact throughout. Add material where deficient and reimpress. 7. Place the framework on the final cast and pour an altered cast. 8. Flow wax onto the oropharyngeal surface of the speech aid extension to make the tissue conditioner and wax tray confluent and establish the appropriate palatal contours. The framework and cast, or the complete denture, can be covered in stone in the flask. Boil out the wax tray and tissue conditioner material and pack with denture resin.

A modeling

hot knife

Thomas P. Treska, DDSs Veterans Administration Medical

A wax tray is stable and easily relieved if overextended. Unusual tray undercuts or angles needed for the partial resection patient need not be eliminated before the impression procedure. Relief of these undercuts is necessary with acrylic resin trays to ensure separation from the final stone cast. Because the wax tray is separated easily from the prosthesis during the boil-out, it is not necessary to “burn” or grind acrylic resin from the framework. The tray shape is duplicated from the existing interim prosthesis on the nasopharyngeal and oropharyngeal side. An arbitrarily shaped acrylic resin tray may be grossly overextended and require time-consuming clinical adjustments. An underextended tray on the nasopharyngeal side will not carry or support the impressionmaterial around or through the residual soft palate remnant. A tray that closely approximates the final prosthesis will allow use of a tissue conditioner final impression without need for border molding (Fig. 2). Duplicating the oropharyngeal side of the interim speech aid duplicates the previously established plane that is compatible with the tongue. The author has used this technique successfully for eight total and five partial soft palate resections. A cleft palate speech aid prosthesis has also been made with this technique. Reprint

requeststo:

DR. RHONDA F. JACOB THE UNIVERSITY OF TEXAS MD ANDERSON CANCER CENTER Box 9,1515 HOLCOMBE HOUSTON. TX 77030

used to remove

palates

from waxed

trial

Center, Des Moines, Iowa

A uniform palatal thickness in a maxillary complete denture is a desirable feature.l Finishing and polishing the palatal surface can be time-consuming and erratic, especially in a palate with a high vault. An accepted method of removing the palatal portion of a maxillary trial baseplate is to remove the trial base from the cast and to cut the palatal portion with a fissure bur in a hand piece or a dental lathe.2 The possibility of cracking and/or warping the waxed trial denture is great when this method is used. A hot knife modeling instrument, Auto-Cutter (Autoworld, Scranton, Penn.), with its scalpel blade attachment, permits removal of the palatal portion of the baseplate without removing it from the cast (Fig. 1). The resulting

Y3tti Prosthodontist, 10/4/37927

562

Veterans Administration

Medical

Center.

Fig. 1. Modeling hot knife used to remove palatal portion of waxed trial denture. Incision has been made in palate through baseplate lingual to maxillary left posterior teeth. SEPTEMBER

1992

VOLUME

68

NUMBER

3

Duplication of interim speech aid for definitive impression tray fabrication.

A wax tray is stable and easily relieved if overextended. Unusual tray undercuts or angles needed for the partial resection patient need not be elimin...
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