Efficient intraoral photogrammetry using self-identifying projective invariant marker.

Abstract

The re-measurement of full-arch implant digital impressions is an important step in denture restoration. This paper provides an efficient oral photogrammetry technology using projective invariant marker, applied in the re-measurement of full-arch implant digital impressions. We have developed a self-recognizing marker with projection invariance, along with its detection code. The marker is installed on the scanning body and used for photogrammetric measurements. Triangulation is utilized to determine the 3D coordinates of the marker, followed by a series of post-processing steps to obtain more accurate 3D coordinates. The experimental data indicate that the optimal working distance is between 200 and 250mm, with a minimum measurement error of less than 0.05mm and an average measurement error of 0.10 mm. The measurement time is less than 2min. The experimental results show that the photogrammetric system can obtain reliable positions of full-arch implants with efficient photogrammetry, without the need to enter the patient's oral cavity, and has potential clinical application value.