Preventing distortion of removable deflasking process Kenneth E. Bloodworth, U.S. Army Dental Activity,
The opinions or assertions contained herein are the private views of the author and are not to be construed as of??cialor as reflecting the views of the United States Army, or the Department of Defense. aLieutenant Colonel, U.S. Army, DC. 10/4/38202
Andre Hashem, Boston University
denture
frameworks
DDSa Fort Qrd, California
Occasionally the clasps and minor connectors of minimal coverage nonplated, rotational path, removable partial denture frameworks are distorted during deflasking after the denture base resin is processed. This distortion can be prevented by placing a small amount (2 to 3 mm) of a resilient material such as
Technique
partial
for two-stage
retrofitted
Dent-Kote (Dentsply International, York, Pa.) around clasps and minor connections that are subject to distortion when the waxed partial denture is ready to flask. The elastomer should not completely encircle the clasps and minor connectors, because this might complicate removal of the elastomer. Contraindicated materials are: polysulfide impression materials (because of the stain and odor imparted to acrylic resin), polyethers, and monophasic addition silicone impression materials, which have relatively high rigidity. Reprint
requests
to:
DR. KENNETH E. BLOODWORTH 999 JEFFERSON STREET MONTEREY, CALIFORNIA 93940-2134
cast post and core
DMD,a and Steven R. Gordon, DMDt Goldman School of Graduate Dentistry, Boston, Mass.
This article describes a method for fabricating a post and core that fits an existing retainer of a fixed partial denture by first making and fitting the post and then by incorporating the core directly onto the post. Restorative dentists are sometimes faced with the problem of making a post and core that fit the retainer of an existing fixed partial denture (FPD). If the FPD is retrievable and is otherwise satisfactory in occlusion, esthetics, contour, and marginal fit, it may be desirable to “retrofit” a new post and core to the existing prosthesis. A solution to this problem is to make a post and core pattern intraorally with autopolymerizing acrylic resin or wax that fits the existing retainer.lm6 A disadvantage of this technique is that any inaccuracy in completely seating the finished post becomes an inaccuracy in seating the retainer over the core, which prevents complete closure of the crown margins. TECHNIQUE 1. Prepare the canal space to the desired dimensions. 2. Make the post intraorally with autopolymerizing acrylic resin (Duralay, Reliance Dental Mfg. CO., aTeaching Fellow, Department of Prosthodontics. I-Deceased, former Associate Professor, Department of Prosthodontics. 10/4/37928
386
Fig. 1. Retrofitted post and core. A, Existing crown; B, Duralay core; C, cast post with mechanical retention on the coronal projection.
AUGUST
1992
VOLUME
68
NUMBER
2
The opinions or assertions contained herein are the private views of the author and are not to be construed as of??cialor as reflecting the views of the United States Army, or the Department of Defense. aLieutenant Colonel, U.S. Army, DC. 10/4/38202
Andre Hashem, Boston University
denture
frameworks
DDSa Fort Qrd, California
Occasionally the clasps and minor connectors of minimal coverage nonplated, rotational path, removable partial denture frameworks are distorted during deflasking after the denture base resin is processed. This distortion can be prevented by placing a small amount (2 to 3 mm) of a resilient material such as
Technique
partial
for two-stage
retrofitted
Dent-Kote (Dentsply International, York, Pa.) around clasps and minor connections that are subject to distortion when the waxed partial denture is ready to flask. The elastomer should not completely encircle the clasps and minor connectors, because this might complicate removal of the elastomer. Contraindicated materials are: polysulfide impression materials (because of the stain and odor imparted to acrylic resin), polyethers, and monophasic addition silicone impression materials, which have relatively high rigidity. Reprint
requests
to:
DR. KENNETH E. BLOODWORTH 999 JEFFERSON STREET MONTEREY, CALIFORNIA 93940-2134
cast post and core
DMD,a and Steven R. Gordon, DMDt Goldman School of Graduate Dentistry, Boston, Mass.
This article describes a method for fabricating a post and core that fits an existing retainer of a fixed partial denture by first making and fitting the post and then by incorporating the core directly onto the post. Restorative dentists are sometimes faced with the problem of making a post and core that fit the retainer of an existing fixed partial denture (FPD). If the FPD is retrievable and is otherwise satisfactory in occlusion, esthetics, contour, and marginal fit, it may be desirable to “retrofit” a new post and core to the existing prosthesis. A solution to this problem is to make a post and core pattern intraorally with autopolymerizing acrylic resin or wax that fits the existing retainer.lm6 A disadvantage of this technique is that any inaccuracy in completely seating the finished post becomes an inaccuracy in seating the retainer over the core, which prevents complete closure of the crown margins. TECHNIQUE 1. Prepare the canal space to the desired dimensions. 2. Make the post intraorally with autopolymerizing acrylic resin (Duralay, Reliance Dental Mfg. CO., aTeaching Fellow, Department of Prosthodontics. I-Deceased, former Associate Professor, Department of Prosthodontics. 10/4/37928
386
Fig. 1. Retrofitted post and core. A, Existing crown; B, Duralay core; C, cast post with mechanical retention on the coronal projection.
AUGUST
1992
VOLUME
68
NUMBER
2
