USE OF A HOOPER DUPLICATOR
Figure 1 The dentures containing the reline impressions are sent to the laboratory.
Figures 2 through 5 The impressions are beaded or boxed and poured in the same manner as final impressions. The casts are allowed to set.
Figure 6 The beading wax is removed from the denture and the cast.
Figure 7 The cast is then trimmed on the cast-trimmer. The land area is trimmed in the same manner as was done for master casts for complete dentures.
Figure 8 Index notches are cut in the base of the cast.
Figures 9 and 10 The instrument shown is a Hooper Duplicator. It is a rigid jig which will maintain the relationship of the teeth to the cast.
Figure 11 Impression plaster is mixed and is placed in the lower portion of the Hooper Duplicator.
Figure 12 The plaster is smoothed and the teeth are set into the plaster so that an occlusal index is formed. The teeth should penetrate the plaster two to three millimeters.
Figure 13 A second mix of impression plaster is made and is placed on the surface of the cast.
Figure 14 The top of the Hooper Duplicator is placed in position.
Figure 15 The plaster is smoothed on the top of the Hooper Duplicator and around the cast.
Figure 16 The mounting has been completed. The use of the Hooper Duplicator will maintain the relative position of the teeth to the cast surface after the denture is separated from the cast. The occlusal index of the teeth is of a sufficient depth that the teeth may be removed from the denture and a complete new base (rebase) made.
Figure 17 The top portion of the Hooper Duplicator is placed in hot water to soften the impression material so that the denture may be removed from the cast.
Figure 18 The denture is separated from the cast.
Figure 21 Any undercuts which remain in the denture base must be removed so that the flask will separate when the dentures are invested.
Figure 22 The border of the denture is beveled in the direction shown here. The purpose of this beveling is to permit the easier application of tinfoil substitute after the denture is invested. (See Figure 64.)
Figure 23 The denture is placed in the occlusal index on the Hooper Duplicator.
Figure 24 The Hooper Duplicator is then re-assembled.
Figure 25 This shows the Hooper Duplicator re-assembled with the denture in place. At this point, the denture may be waxed to the cast. No wax should extend onto the polished surface of the denture. The cast is then removed from the Hooper Duplicator and is invested in the usual manner.
VARIATIONS IN THE RELINE/REBASE PROCEDURE
Figures 26 and 27 Less dimensional change will occur in a maxillary reline when the palate is removed. Removing the palate permits the relined or rebased denture to have a palate of uniform thickness. Removal of the palate is one of many variations possible when a Hooper Duplicator or similar jig is used.
Figure 28 A rebase may be done by removing all of the denture base material from the teeth. When resin teeth are used, the teeth must be left in a horseshoe as is shown in this illustration. If porcelain teeth are used, they may be removed from the denture base by heating them with a waxing torch. This softens the resin around the teeth and permits their removal. The teeth are then placed individually into the index in the bottom of the Hooper Duplicator. However, leaving the teeth in a horseshoe of resin makes re-assembly and waxing easier.
Figure 29 The Hooper Duplicator is assembled to be sure there are no interferences between the teeth and the cast.
Figure 30 The teeth are tacked to the index with sticky wax.
Figure 31 The Hooper Duplicator is assembled and the teeth are sealed to the cast.
Figure 32 After the wax sealing the teeth to the cast has solidified, the Hooper Duplicator is separated. The teeth will adhere to the cast. Additional wax is then placed around the teeth to secure the teeth more firmly to the cast.
Figures 33 through 37