Effect of Splinting in Accuracy of Two Implant Impression Techniques
Because there is no consensus in the literature about the need for a splint between copings, the aim of this study was to evaluate, in vitro, the accuracy of 2 impression techniques for implant-supported prostheses. A master cast was fabricated with four parallel implant abutment analogs and a passive framework. Two groups with 5 casts each were formed: Group 1 (squared impression copings with no splint: S) and Group 2 (splinted squared impression copings, using metal drill burs and Pattern resin: SS). The impression material used was polyvinyl siloxane with open trays for standard preparation of the casts. For each cast, the framework was positioned, and a titanium screw was tightened with 10 N·cm torque in analog A, after which measurements of the abutment-framework interface gaps were performed at analogs C and D. This process was repeated for analog D. These measurements were analyzed using software. A one-way analysis of variance (ANOVA) with a confidence interval of 95% was used to analyze the data. Significant differences were detected between S and SS in relation to the master cast (P ≤ 0.05). The median values of the abutment-framework interface gaps were as follows: master cast: 39.64 μm; squared impression copings with no splint: 205.86 μm; splinted squared impression copings: 99.19 μm. Under the limitations of this study, the technique presented for Group 2 produces better results compared with the technique used for Group 1.

Figure 1 . Brass master cast. Figure 2. Positioning of the analogs with the aid of a surveyor. Figure 3. Analogs positioned in master cast. Figure 4. Master cast and metal framework. Figure 5. Bar composed of four cylinders titanium. Figure 6. Non-splinted impression technique.

Figure 7 . Splinted impression technique, splinted with drill steel and Pattern resin. Figure 8. Hemostatic pincer holding the analogs during torque for casting stone. Figure 9. Four analogs were positioned sequentially from A to D. Figure 10. The measurements were performed using the software (Leica Imaging System, Cambridge, UK).
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