Figure 2. Rubber base impression after tooth preparation for bar framework fabrication. The O-ring attachment used for the implant overdentures consisted of a brass abutment analogue, metal O-ring, Cisplatin clinical and white and red color silicone rings. The laboratory analogue was duplicated in putty rubber base relined with light body polyvinylsiloxane. Pattern resin was poured into the duplicate mold to fabricate the castable stud attachment (Figure 3). The metal O-ring with silicone ring fitted well with the duplicate pattern resin abutment analogue (Figure 4). The excess dowel length of the pattern resin was removed. A wax pattern was made for the bar framework. The abutment teeth were connected using 2 mm sprue former wax. The duplicate pattern resin stud attachment was waxed to the bar framework (Figure 5).

Two stud attachments were placed. One of the studs was attached to the distal aspect of tooth 45 and another to the mesial aspect of tooth 33 above the bar. The casting of the framework was done in Co-Cr alloy using conventional procedures. The bar framework with stud attachments was finished and polished. It was tried in the patient��s mouth and the fit was satisfactory. The bar and stud framework was luted to the abutment teeth using resin cement (Figure 6). Figure 3. O-ring attachment system with duplicated pattern resin post in putty index. Figure 4. Metal O-ring fitting well to the resin post. Figure 5. Wax pattern of the bar framework with the duplicated resin studs attached. Figure 6. Cemented bar framework.

After the cementation of the bar framework, a final impression of the lower arch was made using medium body rubber base material. Care was taken to block the undercuts below the bar with soft wax at the time of impression making. Brass abutment analogues which were previously used for duplication were placed in the impression and a master cast was poured in dental stone (Figure 7). The metal O-ring was placed on the laboratory analogues on the master cast and a record base was fabricated. A relief block-out was performed around the attachment for easy removal of the record base. A record rim was made and the jaw relationship recorded using conventional techniques. Teeth arrangement was done and a trial was made. After a satisfactory trial, the trial denture was invested and dewaxed.

The metal O-rings were retrieved from the temporary record base and were placed on the abutment analogue (Figure 8). Block out was performed beneath the O-ring. Heat polymerizing acrylic resin was packed and cured. Finishing and polishing of the processed denture were carried out. Relief was provided Dacomitinib around the O ring and bar framework area so that no movement of the framework occurred as the denture base was moved slightly on and off the tissues (Figure 9). Fit checker disclosing agent was used for this purpose to identify contact between the attachment mechanisms and the denture base. Finally the denture was placed (Figure 10).