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Internally weighted mandibular dentures
SCHELB
7. Insert the plunger and express the excess air. 8. Hold the impression on a vibrator and slowly express the stone from the syringe, filling the preparations from the bottom up (Fig. 4). When the tooth impressions are full, the stone may be added more rapidly to the desired thickness. 9. Empty the syringe before the stone sets and immediately clean the syringe and tip to prevent damage. Lubricate the O-ring. 10. The completed cast will usually be free of voids (Fig. 5). Fig. 5. Stone cast with no voids.
3.
4. 5. 6.
buildup of excessivehydraulic pressure as the stone mix is expressed (Fig. 2). Use a clean syringe and ensure that the plunger works easily and smoothly without the tip in place. Place the top on the syringe and check it again. Make a vacuumed mix of die stone according to manufacturer’s directions. Fill the barrel of the syringe with the stone mix and wipe the excess from sides with a paper towel (Fig. 3).
Internally
REFERENCES 1. Council of Dental Materials and Devices. American Dental Association specification No. 19 for nonaqueous, elastomeric dental impression materials. J Am Dent Assoc 1977;94:733-41. 2. Lacy A, Treleaven S, Jendresen M. The effect of selected surfactants on the wetting behavior of gypsum die stone on impression materials. Can Dent Assoc J 1977;43:36-40. 3. .%helb E, Mazzocco C, Jones J, Prihoda T. Compatibility of type IV dental stones with polyvinyl siloxane impression materials. J PROSTHETDENT 1987;58:19-22. Reprint requests to: DR. ERNSTSCHELB THE UNIVERSITYOF TEXAS HEALTH SCIENCE CENTER AT SAN ANTONIO
DENTAL SCHOOL SAN ANTONIO,TX 78284-7890
weighted mandibular
dentures
Alvaro J. Hurtado, D.D.S., M.S. Miami, Fla.
W
eighted mandibular dentures have been used for the management of severely resorbed mandibular residual alveolar ridges. Advocates claim the denture aids in retention if it weighs approximately 30 dwt.’ When a weighted mandibular denture is indicated, but the supporting edentulous alveolar mucosa is not appropriate for loading with a cast metal base, an internally weighted mandibular denture may be used. This treatment provides the benefit of the additional weight and avoids direct contact of the metal base with the mucosa. Wormley and Bruntor? described a technique for making internally weighted mandibular dentures by using a metal frame with metal sprues on the facial and 122
Fig. 1. Pencil outline for wax spacer and tissue stops. JULY 1988
VOLUME
60
NUMBER
1
INTERNALLY
WEIGHTED
MANDIBULAR
DENTURES
Fig. 2. Chrome-cobalt alloy frame.
Fig. 3. Ridge side of completed weighted denture.
lingual sides to hold the metal insert in a suspended position in the denture flask during the packing process. Berry and Funk’ described a Vitallium (Austenal Dental Inc., Chicago, Ill.) frame used to prevent a mandibular denture from breaking. Tissue stops on the metal frame aid in positioning it against the working stone cast during the packing process. This article describes a method to use tissue stops to position the metal frame and add considerable weight to aid in retention. PROCEDURE
stops should be placed over the crest of the edentulous mandibular ridge in the position of the second molars and canines and should be approximately 2 mm wide and 3 mm long (Fig. 1). 2. Place one sheet of baseplate wax over the master cast and trim it to the pencil mark outline. 3. Use a fine scalpel to remove the wax from the four tissue stops and seal the wax in position. 4. Duplicate the master cast with the wax on it and pour it in stone. 5. Make a metal frame of chrome-cobalt to fit directly over the waxed portion of the cast. The frame must weigh approximately 16 dwt and the spacesmust be wide enough to permit the acrylic resin to pass through during the packing process (Fig. 2). Stainless steel rods may be soldered to the frame for additional weight. Care must be taken to allow enough space to set the teeth. 6. Place the metal on the original master cast with the wax spacer, set the teeth, and complete the esthetic try-in. 7. Flask and boil out but, before packing the acrylic resin, recover and clean the metal frame and cement it to the master cast at the four tissue stops with cyanoacrylate cement. 8. Apply separating medium to the stone surface and pack the acrylic resin in the usual manner. The internally weighted mandibular denture has most of the advantages of heavy cast metal bases and it is easier to adjust and reline (Fig. 3). REFERENCES I.
Grunewald AH. Gold base lower denture. J PROSTHETDENT 1964;14:432-41. 2. Wormley JH, Brunton DA. Weighted mandibular dentures. J PROSTHETDENT 1974;32:101-2. 3. Berry HH, Funk OJ. Vitallium strengthener to prevent lower denture breakage. J PROSTHETDENT 1971;26:532-5.
Heprmtrequest,lo: DR. ALVAROJ. HURTADO 10115 N. W. 41‘~ LANE FONTAINEBLEAU PARK MIAMI, FL 33172
1. Mark with a pencil the desired extension of the metal frame and the position of the stops on the cast. The
THE JOURNAL
OF PROSTHETIC
DENTISTRY
123
7. Insert the plunger and express the excess air. 8. Hold the impression on a vibrator and slowly express the stone from the syringe, filling the preparations from the bottom up (Fig. 4). When the tooth impressions are full, the stone may be added more rapidly to the desired thickness. 9. Empty the syringe before the stone sets and immediately clean the syringe and tip to prevent damage. Lubricate the O-ring. 10. The completed cast will usually be free of voids (Fig. 5). Fig. 5. Stone cast with no voids.
3.
4. 5. 6.
buildup of excessivehydraulic pressure as the stone mix is expressed (Fig. 2). Use a clean syringe and ensure that the plunger works easily and smoothly without the tip in place. Place the top on the syringe and check it again. Make a vacuumed mix of die stone according to manufacturer’s directions. Fill the barrel of the syringe with the stone mix and wipe the excess from sides with a paper towel (Fig. 3).
Internally
REFERENCES 1. Council of Dental Materials and Devices. American Dental Association specification No. 19 for nonaqueous, elastomeric dental impression materials. J Am Dent Assoc 1977;94:733-41. 2. Lacy A, Treleaven S, Jendresen M. The effect of selected surfactants on the wetting behavior of gypsum die stone on impression materials. Can Dent Assoc J 1977;43:36-40. 3. .%helb E, Mazzocco C, Jones J, Prihoda T. Compatibility of type IV dental stones with polyvinyl siloxane impression materials. J PROSTHETDENT 1987;58:19-22. Reprint requests to: DR. ERNSTSCHELB THE UNIVERSITYOF TEXAS HEALTH SCIENCE CENTER AT SAN ANTONIO
DENTAL SCHOOL SAN ANTONIO,TX 78284-7890
weighted mandibular
dentures
Alvaro J. Hurtado, D.D.S., M.S. Miami, Fla.
W
eighted mandibular dentures have been used for the management of severely resorbed mandibular residual alveolar ridges. Advocates claim the denture aids in retention if it weighs approximately 30 dwt.’ When a weighted mandibular denture is indicated, but the supporting edentulous alveolar mucosa is not appropriate for loading with a cast metal base, an internally weighted mandibular denture may be used. This treatment provides the benefit of the additional weight and avoids direct contact of the metal base with the mucosa. Wormley and Bruntor? described a technique for making internally weighted mandibular dentures by using a metal frame with metal sprues on the facial and 122
Fig. 1. Pencil outline for wax spacer and tissue stops. JULY 1988
VOLUME
60
NUMBER
1
INTERNALLY
WEIGHTED
MANDIBULAR
DENTURES
Fig. 2. Chrome-cobalt alloy frame.
Fig. 3. Ridge side of completed weighted denture.
lingual sides to hold the metal insert in a suspended position in the denture flask during the packing process. Berry and Funk’ described a Vitallium (Austenal Dental Inc., Chicago, Ill.) frame used to prevent a mandibular denture from breaking. Tissue stops on the metal frame aid in positioning it against the working stone cast during the packing process. This article describes a method to use tissue stops to position the metal frame and add considerable weight to aid in retention. PROCEDURE
stops should be placed over the crest of the edentulous mandibular ridge in the position of the second molars and canines and should be approximately 2 mm wide and 3 mm long (Fig. 1). 2. Place one sheet of baseplate wax over the master cast and trim it to the pencil mark outline. 3. Use a fine scalpel to remove the wax from the four tissue stops and seal the wax in position. 4. Duplicate the master cast with the wax on it and pour it in stone. 5. Make a metal frame of chrome-cobalt to fit directly over the waxed portion of the cast. The frame must weigh approximately 16 dwt and the spacesmust be wide enough to permit the acrylic resin to pass through during the packing process (Fig. 2). Stainless steel rods may be soldered to the frame for additional weight. Care must be taken to allow enough space to set the teeth. 6. Place the metal on the original master cast with the wax spacer, set the teeth, and complete the esthetic try-in. 7. Flask and boil out but, before packing the acrylic resin, recover and clean the metal frame and cement it to the master cast at the four tissue stops with cyanoacrylate cement. 8. Apply separating medium to the stone surface and pack the acrylic resin in the usual manner. The internally weighted mandibular denture has most of the advantages of heavy cast metal bases and it is easier to adjust and reline (Fig. 3). REFERENCES I.
Grunewald AH. Gold base lower denture. J PROSTHETDENT 1964;14:432-41. 2. Wormley JH, Brunton DA. Weighted mandibular dentures. J PROSTHETDENT 1974;32:101-2. 3. Berry HH, Funk OJ. Vitallium strengthener to prevent lower denture breakage. J PROSTHETDENT 1971;26:532-5.
Heprmtrequest,lo: DR. ALVAROJ. HURTADO 10115 N. W. 41‘~ LANE FONTAINEBLEAU PARK MIAMI, FL 33172
1. Mark with a pencil the desired extension of the metal frame and the position of the stops on the cast. The
THE JOURNAL
OF PROSTHETIC
DENTISTRY
123