Accuracy investigation of dual mode markers for navigated dental implant surgery with a new 3D realtime navigation system DENACAM

Dental implants are in 96% positioned free hand including a risk of suboptimal placement. A miniaturized navigation system has been developed to overcome these limitations by fixing two stereo cameras to the drill to guide the surgeon during implant insertion. The aim of the present study was to develop and analyse a dual-mode marker with a highly precise, high contrast optical pattern, visible by the camera system, on a precise substrate clearly identifiable on Cone Beam CT (CBCT) images and sterilisable. The marker was developed with a laser engraved optical pattern brought to a ceramic substrate containing two holes to ensure clear identification of the position of the marker within CBCT images. The substrate dimensions were verified with a micrometer gauge and compared to the expected tolerances. The position and angular error of the optical pattern on the substrate was analysed on optical microscope images. Six markers were exposed to 20 cleaning and steam sterilization cycles and changes were analysed on optical and scanning electron microscope (SEM) images. Energy dispersive X-ray spectroscopy (EDX) analysis was performed to study the percentage composition of the different elements. Substrate dimensions and angular errors remained always within the defined tolerances. Positioning errors were higher than the tolerances for some of the measurements. The error distribution indicates a systematic error. Results were reproducible over the samples. No changes could be observed visually on the optical Health Sciences EPiC Series in Health Sciences Volume 1, 2017, Pages 219–223 CAOS 2017. 17th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery K. Radermacher and F. Rodriguez Y Baena (eds.), CAOS 2017 (EPiC Series in Health Sciences, vol. 1),