Technique for the repair of removable partial denture backings

Technique for the repair of removable denture backings Leo F. Broering,

D.M.D.,*

and William

partial

M. Gooch**

USA Dental Activity, Hanau, West Germany, and Fort Knox, Ky.

ccasionally a patient has an excellent fitting, 0 properly designed, esthetically acceptable removable partial denture, but has broken or lost the retentive pin from the backing. Conventional soldering techniques transmit high temperatures to the acrylic resin in the damaged areas, necessitating a remake of these parts. This article describes ‘a technique that eliminates the need to remake’ the removable partial denture and replace the acrylic resin portions of the denture base. The Hydroflame II (Henes Products Corp., Phoenix, Ariz.), used in this technique, is a precision soldering unit that produces hydrogen and oxygen at a controlled rate and mixes them in the correct proportion to maintain a constant flame temperature. Different torch tip sizes that allow tailoring flame size to fit specific requirements can be used.

Fig. 1. Broken tient’s mouth.

removable

partial

denture

in

pa-

TECHNIQUE 1. Insert the removable partial denture in the patient’s mouth to verify fit and stability (Fig. 1). 2. Using irreversible hydrocolloid, make an impression with the removable partial denture in place. 3. Block out tissue undercuts present in the acrylic resin of the denture base and, using correctly measured water-to-powder ratios, pour the impression with vacuum-spatulated dental stone. 4. Carefully remove the removable partial denture from the cast so as not to break the abutment teeth or the teeth adjacent to the backing. 5. Make a replacement pin by bending in half a 0.036-gauge stainless steel wire about 1 inch in length. This is then soldered together with 0.025-gauge silver

The views or opinions expressed herein are those of the authors and do not necessarily reflect those of the U.S. Army. *Commander and Chief of Removable Prosthetics, 92nd Medical Detachment. **Senior Technician, Removable Prosthetic Laboratory, Fort Knox, KY.

582

Fig. 2. Replacement pin fabricated with Hydroflame II pinpoint torch tip CA).

Fig. 3. Backing roughened pin removed.

OCTOBER

1983

and remaining

VOLUME

50

parts of

NUMBER

4

REPAIRING

REMOVABLE

PARTL4L

Fig. 4. New pin soldered removable partial denture point torch tip CA).

Fig. 5. Finished

DENTURE

BACKINGS

to backing of with Hydroflame

existing II pin-

with

tooth-colored

repair

resl:;

for

plastic

facings or zinc phosphate cement for porcelain facings. If the original facing was not lost, it can be cemented in the same manner (Fig. 6). 10. Replace the removable partial denture in the

THE

JOURNAL.

OF PROSTHETIC

DENTISTRY

cemented

to replacement

Fig. 7. Removable partial denture with ing in patient’s mouth for final check.

pin on backing.

solder (Unitek Corp., Monrovia, Calif.) with the Hydroflame II torch (Fig. 2). 6. Roughen the surface on the backing where the retentive pin was located with an abrasive stone. At the same time, any remaining portion of a broken pin can be removed (Fig. 3). 7. Solder the pin to the backing with the Hydroflame II torch. Alligator clips or other suitable holders can be used to hold the stainless steel wire used to replace the broken pin in the proper position to the framework (Fig. .I). 8. Shape the new pin with disks and burs to resemble the origi.nal pin (Fig. 5). 9. Return the removable partial denture to the cast and select and contour a new facing. The facing can be cemented

Fig. 6. Facing

repaired

patient’s mouth and check for interproximal and occlusal (Fig. 7).

interferences

with

pin.

fine articulating

fac-

contact paper

SUMMARY An easy and practical technique has been described for replacement of a removable partial denture retentive pin as an alternative to fabricating a new removable partial denture or reprocessing the acrylic resin part of the old metal framework. The technique uses the Hydroflame II soldering unit, which provides controlled, localized application ,of heat without damaging any acrylic resin that may be present. We wish to express OUT gratitude to Colonel Marvin for his review and constructive criticism of this article.

Keprmt reyueststo: DR. LEO F. BROERINC 92~x1 MED DET (D5) APO, Nw YORK, NY 09165

F. Grower