Impression Techniques for Multiple Implants:
A Photoelastic Analysis. Part I: Comparison of Three
Direct Methods
A Photoelastic Analysis. Part I: Comparison of Three
Direct Methods
The purpose of this article was to compare through photoelastic analysis the stress distribution in 3 direct transfer techniques for implants with splinting. Three photoelastic resin blocks were made with 2 implants placed parallel to each other and 2 square transfer copings splinted. Both transfers were splinted with acrylic resin chemically activated in 3 different techniques: metallic sticks (T1), prefabricated acrylic bars (T2), or dental floss (T3). A circular polariscope was used, and the distortion energy (E) was calculated in 4 periods: 20 minutes and 3, 24, and 36 hours. Statistically significant differences were found among the 3 techniques (P < .05). The dental floss presented the greatest distortion energy values (T3 = 0.469 Kgf/mm2) and the metallic sticks the lowest values (T1 = 0.0 Kgf/mm2). Thus, the metallic sticks technique (T1) appears to be the most accurate protocol to be used for implant-supported prosthesis with multiple abutments.
Figure 1. Master block with demarcations in lead and modified and fixed transfers. Figure 2. Master block in the base of the wood box. Figure 3. Transfers positioned on the implants in the photoelastic block and screws with torque of 10 N. Figure 4. Graph for the BB′ area in T3 after a period of 36 hours with resin Dencrilay (E = 0.469 kgf/mm2).
Figure 5. Photoelastic response of the area AA′ after a period of 36 hours in T1. Figure 6. Photoelastic response of the area AA′ after a period of 36 hours in T2. Figure 7. Photoelastic response of the area AA′ after period of 36 hours in T3. Figure 8. Photoelastic response of the area BB′ after a period of 36 hours in T1. Figure 9. Photoelastic response of the area BB′ after period of 36 hours in T2. Figure 10. Photoelastic response of the area BB′ after a period of 36 hours in T3.
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