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The versatile air abrasive blaster
The versatile
air abrasive
blaster
William W. Nagy, D.D.S.,* and Charles G. Stankewitz, D.D.S.** U.S. Army Dental Activity, Fort Sam Houston, Tex., and U.S. Army Dental Activity, Fort Ord, Calif. The air abrasive blaster with pencil-type handpiece and various powdered abrasives has been a mainstay in prosthodontic laboratories for many years. A dental laboratory technician can clean, carve, polish, and shape dental restorations after deflasking with a precisely controlled, highspeed stream of abrasive particles in a fraction of the time required by conventional methods. New uses are discovered daily for this versatile device, although it is still of most benefit in fixed partial denture procedures. No ceramist would be without it for preparing metal frameworks for porcelain. The blaster quickly removes contaminants, lifts off burnished fins of alloy, increases the available amount of surface area, and permits easier wetting of the metal by the porcelain. When followed by steam cleaning, nothing prepares the surface more effectively.’ Removing artificial stone and debris A time-consuming and thankless job is that of using hand chisels or rotary instruments to remove stone and debris remaining around plastic denture teeth after deflasking a complete or removable partial denture. Regardless of the care taken when using chisels or burs, scratches and gouges seem to appear. The pencil blaster with 25- or 50-micron aluminum oxide abrasive will remove this debris in one third of the time without marring the surface. Air pressure should be decreased to 50 psi and the pencil tip kept moving to prevent burning or abrading the acrylic resin. Surfaces prepared in this manner are much easier to polish than those prepared with hand or rotary instruments. However, if this technique is used around porcelain teeth, the glaze will be removed. Carving acrylic resin and revitalizing old dentures Carving resin is at times desirable, such as when an improper wax-up of the denture causes the acrylic resin flash
to cover more of the plastic teeth than desired, resulting in poor estheticsof the finished denture. The air pencil with 25-micron aluminum oxide will quickly abradethis acrylic resin to exposethe teeth. Old dentures can be revitalized by using the abrasive blaster to remove stains,calculus,and poorly contoured or dead resin and to prepare the surfacesfor repair. In fixed partial dentures, the abrasive blaster may be used to remove set cement from the inside of cast crowns and interim resin restorations or to prepare the inside of interim restorations for relining. Reshaping plastic denture teeth Plastic denture teeth often need to be separatedto appear as individual teeth. Opening the incisal embrasure with a flexible disk or jeweler’s saw followed by rounding and refining with the air pencil can restore the individual tooth look. Making articulating paper marks visible The pencil blaster can be used to dull shiny surfacesto facilitate marking of a highly polished chrome removable partial denture framework or fixed partial denture when adjusting the occlusion.Dusting the restsor other parts of the framework that may be interfering with the occlusion with 25-micron aluminum oxide will permit the articulating paper marks to becomereadily visible. SUMMARY The air-abrasive blaster has become an indispensable tool in the prosthodontic laboratory. New usesare discovered daily. A number of them are describedin this article. Reprint requests to: DR. WILLIAM W. NAGY 2646 PEBBCE VALLEY SAN ANTONIO, TX 78232
REFERENCE
The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or Department of Defense. *Colonel, U.S. Army, DC: Chief, Fixed Prosthodontics. **Colonel, U.S. Army, DC; Chief, Removable Prbsthodontics.
1. Preston JD, Bergen R. Some laboratory variables metal alloys. Dent Clin North Am 19’7’7;21:‘717-28.
affecting
ceramo-
10/4/183a4
490
APRIL
1990
VOLUME
63
NUMBER
4
air abrasive
blaster
William W. Nagy, D.D.S.,* and Charles G. Stankewitz, D.D.S.** U.S. Army Dental Activity, Fort Sam Houston, Tex., and U.S. Army Dental Activity, Fort Ord, Calif. The air abrasive blaster with pencil-type handpiece and various powdered abrasives has been a mainstay in prosthodontic laboratories for many years. A dental laboratory technician can clean, carve, polish, and shape dental restorations after deflasking with a precisely controlled, highspeed stream of abrasive particles in a fraction of the time required by conventional methods. New uses are discovered daily for this versatile device, although it is still of most benefit in fixed partial denture procedures. No ceramist would be without it for preparing metal frameworks for porcelain. The blaster quickly removes contaminants, lifts off burnished fins of alloy, increases the available amount of surface area, and permits easier wetting of the metal by the porcelain. When followed by steam cleaning, nothing prepares the surface more effectively.’ Removing artificial stone and debris A time-consuming and thankless job is that of using hand chisels or rotary instruments to remove stone and debris remaining around plastic denture teeth after deflasking a complete or removable partial denture. Regardless of the care taken when using chisels or burs, scratches and gouges seem to appear. The pencil blaster with 25- or 50-micron aluminum oxide abrasive will remove this debris in one third of the time without marring the surface. Air pressure should be decreased to 50 psi and the pencil tip kept moving to prevent burning or abrading the acrylic resin. Surfaces prepared in this manner are much easier to polish than those prepared with hand or rotary instruments. However, if this technique is used around porcelain teeth, the glaze will be removed. Carving acrylic resin and revitalizing old dentures Carving resin is at times desirable, such as when an improper wax-up of the denture causes the acrylic resin flash
to cover more of the plastic teeth than desired, resulting in poor estheticsof the finished denture. The air pencil with 25-micron aluminum oxide will quickly abradethis acrylic resin to exposethe teeth. Old dentures can be revitalized by using the abrasive blaster to remove stains,calculus,and poorly contoured or dead resin and to prepare the surfacesfor repair. In fixed partial dentures, the abrasive blaster may be used to remove set cement from the inside of cast crowns and interim resin restorations or to prepare the inside of interim restorations for relining. Reshaping plastic denture teeth Plastic denture teeth often need to be separatedto appear as individual teeth. Opening the incisal embrasure with a flexible disk or jeweler’s saw followed by rounding and refining with the air pencil can restore the individual tooth look. Making articulating paper marks visible The pencil blaster can be used to dull shiny surfacesto facilitate marking of a highly polished chrome removable partial denture framework or fixed partial denture when adjusting the occlusion.Dusting the restsor other parts of the framework that may be interfering with the occlusion with 25-micron aluminum oxide will permit the articulating paper marks to becomereadily visible. SUMMARY The air-abrasive blaster has become an indispensable tool in the prosthodontic laboratory. New usesare discovered daily. A number of them are describedin this article. Reprint requests to: DR. WILLIAM W. NAGY 2646 PEBBCE VALLEY SAN ANTONIO, TX 78232
REFERENCE
The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or Department of Defense. *Colonel, U.S. Army, DC: Chief, Fixed Prosthodontics. **Colonel, U.S. Army, DC; Chief, Removable Prbsthodontics.
1. Preston JD, Bergen R. Some laboratory variables metal alloys. Dent Clin North Am 19’7’7;21:‘717-28.
affecting
ceramo-
10/4/183a4
490
APRIL
1990
VOLUME
63
NUMBER
4