Hi all,
I just read this interesting thread and would like to add a few comments regarding accuracy of scanners and 3Shape scanners in particular.
Most scanner manufacturers do not disclose how they measure their accuracy claims. Hence, claimed accuracies – typically in the area of 20 microns – cannot be compared nor even confirmed.
How do 3Shape ensure high and consistent accuracy The science of high accuracy measurement – metrology - applies reference objects with accuracies much higher than the scanner. These objects can only be manufactured by specialized accredited companies or metrology laboratories. By defining and introducing proper mutual reference objects such as these, it becomes clear that different scanner brands perform quite differently.
3Shape performs various tests to assess scanner accuracy and ensure consistent high quality of the scanners we manufacture. Today, thousands of implant bars are successfully produced with 3Shape software - every month.
For those of you who are interested, I have uploaded a report explaining how we measure accuracy of our scanners. The report confirms 3Shape’s D800 scanner’s ability to scan highly accurate implant bar and bridge cases.
Click here to read more: View attachment 3Shape Implant Bridge Accuracy Evaluation.pdf Scanner calibration is important It is an undeniable law of physics that all materials – and thus also scanner hardware – will expand and contract according to changes in temperature. Scanner hardware can also be affected by rough handling such as during transportation. For demanding work, such as long span bridges and implant bars, it is especially important that a scanner is re-calibrated when moved or when the lab’s temperature changes. All 3Shape scanners come with special calibration objects with a known accuracy factor that is much higher than the scanner’s accuracy capability. Software algorithms cannot compensate for temperature effects because the scanner hardware itself contains weldings, fasteners, glued sections, varying loads, etc., and is thus prone to highly complex expansion and contraction.
I hope this clarifies any questions.
