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Fabrication of the hollow bulb obturator
Fabrication
of the hollow
bulb obturator
Bob Palmer* and Kyle W. Coffey, D.D.S.** Veterans Administration Hospital, Columbia, MO.
T
he effective obturation of palatal defects presents a challenge, especially in the edentulous patient. In both the dentulous and edentulous mouth, retention is reduced as the weight of the obturator increases to fill the anatomic defect. Hollow prostheses decrease the overall weight and absorb less sound than solid prostheses of equal size. In the interest of clarity and simplicity, a dentulous patient was selected to illustrate the technique. Teeth and clasps have been purposely omitted. The principles illustrated apply to any size obturator.
6. Remove the plaster cap when set, take out the clay and discard. 7. Coat the tissue side of the plastic cap with a suitable separating medium.
PROCEDURE 1. Make an impression that includes the palatal defect to be obturated (Fig. 1). 2. Pour a stone cast, separate, and key at the border of the bond as indicated (Fig. 1). 3. Apply a suitable separating medium to the stone surface. 4. Sculpt in clay the palatal defect and the missing alveolus (Fig. 2). 5. Pour a plaster cap over the clay build-up, including the keys, in the master cast (Fig. 3). *Senior **Chief,
Laboratory Technician, Dental Service.
Certified
Dental
Technician.
Fig. 1. Cast of palatal defect (A) to be obturated with a hollow bulb. THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 2. Palatal defect and missing alveolus sculptured in clay (B).
Fig. 3. Plaster cap (C) is poured over sculptured clay
and keys in master cast.
1”ILMER
AND
CQFFt:\
Fig. 4. Master cast (D, E, and F) to which orthodontic acrylic resin has been applied Additional resin is dusted onto border of E and F, and border between D and E. Plaster cast and F are inverted onto master cast and resin is allowed to cure.
10. Combine powder and liquid acrylic resin into the border of E and F, and into the border of II adjacent to E (Fig. 4). 11. Invert the plaster cap and F into the master cast. Be sure the acrylic resin is kept moist with monomer before closure. 12. Check the keys for proper fit and allow the acrylic resin to cure. 13. Remove and finish the bulb in the usual manner (Fig. 5).
SUMMARY The fabrication of a hollow bulb without the use of water and pressure has been described. When water and pressure are used, it requires opening t-he bulb, draining the water, and resealing. Tissue conditioners, soft liners, clasps, teeth, and other additions may be used in conjunction with the restoration. Adjustments are easily made. Fig. 5. Finished and polished (G) on master cast.
hollow
bulb
obturator
8. Apply a thin layer of orthodontic acrylic resin to the defect. Keep the acrylic resin short (Fig. 4). 9. Cure the acrylic resin without pressure or heat.
596
APRIL
1985
VOLUME
53
NUMBER
4
of the hollow
bulb obturator
Bob Palmer* and Kyle W. Coffey, D.D.S.** Veterans Administration Hospital, Columbia, MO.
T
he effective obturation of palatal defects presents a challenge, especially in the edentulous patient. In both the dentulous and edentulous mouth, retention is reduced as the weight of the obturator increases to fill the anatomic defect. Hollow prostheses decrease the overall weight and absorb less sound than solid prostheses of equal size. In the interest of clarity and simplicity, a dentulous patient was selected to illustrate the technique. Teeth and clasps have been purposely omitted. The principles illustrated apply to any size obturator.
6. Remove the plaster cap when set, take out the clay and discard. 7. Coat the tissue side of the plastic cap with a suitable separating medium.
PROCEDURE 1. Make an impression that includes the palatal defect to be obturated (Fig. 1). 2. Pour a stone cast, separate, and key at the border of the bond as indicated (Fig. 1). 3. Apply a suitable separating medium to the stone surface. 4. Sculpt in clay the palatal defect and the missing alveolus (Fig. 2). 5. Pour a plaster cap over the clay build-up, including the keys, in the master cast (Fig. 3). *Senior **Chief,
Laboratory Technician, Dental Service.
Certified
Dental
Technician.
Fig. 1. Cast of palatal defect (A) to be obturated with a hollow bulb. THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 2. Palatal defect and missing alveolus sculptured in clay (B).
Fig. 3. Plaster cap (C) is poured over sculptured clay
and keys in master cast.
1”ILMER
AND
CQFFt:\
Fig. 4. Master cast (D, E, and F) to which orthodontic acrylic resin has been applied Additional resin is dusted onto border of E and F, and border between D and E. Plaster cast and F are inverted onto master cast and resin is allowed to cure.
10. Combine powder and liquid acrylic resin into the border of E and F, and into the border of II adjacent to E (Fig. 4). 11. Invert the plaster cap and F into the master cast. Be sure the acrylic resin is kept moist with monomer before closure. 12. Check the keys for proper fit and allow the acrylic resin to cure. 13. Remove and finish the bulb in the usual manner (Fig. 5).
SUMMARY The fabrication of a hollow bulb without the use of water and pressure has been described. When water and pressure are used, it requires opening t-he bulb, draining the water, and resealing. Tissue conditioners, soft liners, clasps, teeth, and other additions may be used in conjunction with the restoration. Adjustments are easily made. Fig. 5. Finished and polished (G) on master cast.
hollow
bulb
obturator
8. Apply a thin layer of orthodontic acrylic resin to the defect. Keep the acrylic resin short (Fig. 4). 9. Cure the acrylic resin without pressure or heat.
596
APRIL
1985
VOLUME
53
NUMBER
4