In Vitro Implant Impression Accuracy Using a New Photopolymerizing SDR Splinting Material

Purpose: The study aims to evaluate three-dimensionally (3D) the accuracy of implant impressions using a new resin splinting material, “Smart Dentin Replacement” (SDR).Materials and Methods: A titanium model of an edentulous mandible with six implant analogues was used as a master model and its dimensions measured with a coordinate measuring machine. Before the total 60 impressions were taken(open tray, screw-retained abutments, vinyl polysiloxane), they were divided in four groups: A (test): copings pick-up splinted with dental floss and photopolymerizing SDR; B (test): see A, additionally sectioned and splinted again with SDR;C (control): copings pick-up splinted with dental floss and autopolymerizing Duralay® (Reliance Dental Mfg. Co., Alsip, IL,USA) acrylic resin; and D (control): see C, additionally sectioned and splinted again with Duralay. The impressions were measured directly with an opto-mechanical coordinate measuring machine and analyzed with a computer-aided design (CAD) geometric modeling software. The Wilcoxon matched-pair signed-rank test was used to compare groups. Results: While there was no difference (p = .430) between the mean 3D deviations of the test groups A (17.5 μm) and B(17.4 μm), they both showed statistically significant differences (p < .003) compared with both control groups (C 25.0 μm, D 19.1 μm). Conclusions: Conventional impression techniques for edentulous jaws with multiple implants are highly accurate using the new photopolymerizing splinting material SDR. Sectioning and rejoining of the SDR splinting had no impact on the impression accuracy.