The patient was restored in the mid-1990s with a maxillary spark erosion superstructure, set on a primary bar supported by implants (Figure 1A, 1B). Mandible was restored with porcelain fused to metal bridges, supported by implants and teeth (Figure 1A, 1B, 2A). The restoration showed a loss of vertical dimension due to abrasion of the acrylic teeth, the presence of extensive pigmentation and discoloration in acrylic teeth, as well as in the pink acrylic resin representing the gingiva (Figure 2A). The implants, as well as the primary bar, did not present any problems, and therefore they were retained. The reconstruction of the superstructure was carried out in an increased vertical dimension. The superstructure carried two latches lingually to the right and left side, which when secured, held the superstructure to the primary bar (Figure 1B, 2B). Every latch had a notch, the opening of which increased its retention to the primary bar during locking (Figure 2B). The latches were somewhat worn-out and loose, and therefore they should be adjusted, as well.

The anterior denture teeth that had been initially used were Dentply 42F, which exhibit central incisors with a length of 10.5 mm and a width of 8.5 mm, a six-anterior-tooth width of 46.5 mm, and square-oval shape. Similar teeth were selected. A facebow record was made, and a semi-adjustable arcon articulator was used (Hanau wide view). No maxillary impression was taken of either the primary bar or the superstructure, but the superstructure itself was used to make a poly-vinyl siloxane putty impression, which served as a cast of the primary bar (Figure 3A). A mandibular alginate impression was taken and a plaster cast was made. Vertical dimension and centric relation were recorded in the increased vertical dimension with alluwax. A protrusive record of 4-6mm was registered in order to adjust the condylar inclination on the articulator. The silicone model of the primary bar, with the superstructure upon it, and the plaster model of the mandible were mounted on the articulator (Figure 3B). Lip support was evaluated and found to be satisfactory. Shade selection was carried out according to the lower teeth. A poly-vinyl siloxane index was made, in order to record the buccal position of the initial situation anterior teeth (Figure 4A). This silicone index would verify the agreement of the new tooth setup with that of the initial situation, mainly in terms of lip support (Figure 4B). Then the anterior and posterior teeth of one quadrant were removed and the new teeth were set, without removing the artificial teeth of the other side, which were left as they were in the former condition (Figure 4B). In this way, there is no complete loss of the reference points of the previous state, in case the new tooth setup is not satisfactory in terms of esthetics. The silicone index was used, in order to verify, that the quadrant acrylic tooth set-up was not substantially different from the initial situation, in terms of lip-support and esthetics, on the stone model before intraoral try-in (Figure 4A, 4B). If lip support is not satisfactory, the quadrant tooth set-up is not recommended, and a wax rim record is preferable, after removing all existing teeth.

In a new appointment, the quadrant tooth set up was evaluated, in terms of vertical dimension, esthetics of the new tooth set-up compared to the initial situation, lip support, shade, centric relation, and phonetics (Figure 5A). Phonetics were evaluated with the pronunciation of “F” and ”V” consonants, in order to assess the position of maxillary incisors in relation with the lower lip, and the pronunciation of “S” consonant, in order to check the position of the incisors during protrusive movement of the mandible.

After the necessary modifications, the waxed superstructure was placed on the articulator, the rest teeth were set-up, and the wax-up of the denture was completed (Figure 5B). The silicone index was used to verify the position of the complete tooth try-in, compared to the initial situation on the model. Afterwards vertical dimension, esthetics, lip support, shade, centric relation, and phonetics were reassessed, in a new clinical appointment. Only the waxed superstructure was then removed, and sent to the dental technician for wax contouring, flasking, wax elimination, packing of the pink acrylic resin, processing, finishing and polishing. The lab was instructed to block out the undercuts, as well as the latch areas used for securing during placement on the primary bar, with plaster of Paris prior to flasking. Plaster of Paris was chosen in order to make it easier to remove, and not to trap acrylic resin around the latches, when packing it. After flasking and wax burn-out, and before pink acrylic packing, the dental technician was asked to remove the remaining old pink acrylic resin by heating, and to cover the metal framework with pink opaque, where it had been removed. When the restoration returned from the lab, it was placed back into the silicone mold on the articulator, and the occlusion was checked. In a subsequent appointment, the repaired superstructure was delivered to the patient, after occlusion was checked, and selective grinding was carried out, as needed (Figure 6A, 6B). The latch slot was then modified, using a #25 scalpel, in order to increase retention as it secured to the primary bar.