Determination the effect of different implant impression splinting techniques on the dimensional accuracy: an in vitro study

The current study aimed to determine the effect of different implant impression splinting techniques on dimensional accuracy. Five analog implant pairs were fixed in 5 jaw models using auto polymerizing resin. After completing the polymerization for 1 week, the impression copings were connected to the analogs. Then, the models were scanned by a laboratory scanner, and the results were used as reference data. In the next step, impression copings were splinted with flowable composite material. Then, the copings were separated from the analogs and connected to one of the analogs by turning 180 degrees, and the copings were scanned with a scanner. This process was repeated for auto polymerizing acrylic resin [which was cut in the middle and then connected by the same material], BIS-acryl composite resin, and light cure glass ionomer. The scanner output was entered into the GOM Inspect software, and the obtained information was saved in three-dimensional form and STL format. The distance, depth, and angle of implants were measured by software, and Friedman's non-parametric test was used for statistical analysis in different splinting materials. Data from this study showed that no significant differences were seen regarding implant distances [p=0.121], implant depths [p=0.334], and implant angles [p=0.856] using different splinting materials compared to the master model. In conclusion, we may demonstrate that due to insignificant differences regarding linear, depth, and angular errors between implants and master model as well as acceptable values of the errors, studied splinting materials are recommended to achieve accurate impressions in implant treatments.