Deep learning-based segmentation of dental implants on cone-beam computed tomography images: A validation study

Objectives: To train and validate a cloud-based convolutional neural network (CNN) model for automated segmentation (AS) of dental implant and attached prosthetic crown on cone-beam computed tomography (CBCT) images. Methods: A total dataset of 280 maxillomandibular jawbone CBCT scans was acquired from patients who underwent implant placement with or without coronal restoration. The dataset was randomly divided into three subsets: training set (n = 225), validation set (n = 25) and testing set (n = 30). A CNN model was developed and trained using expert-based semi-automated segmentation (SS) of the implant and attached prosthetic crown as the ground truth. The performance of AS was assessed by comparing with SS and manually corrected automated segmentation referred to as refined-automated segmentation (R-AS). Evaluation metrics included timing, voxelwise comparison based on confusion matrix and 3D surface differences. Results: The average time required for AS was 60 times faster (<30 s) than the SS approach. The CNN model was highly effective in segmenting dental implants both with and without coronal restoration, achieving a high dice similarity coefficient score of 0.92 +/- 0.02 and 0.91 +/- 0.03, respectively. Moreover, the root mean square deviation values were also found to be low (implant only: 0.08 +/- 0.09 mm, implant+restoration: 0.11 +/- 0.07 mm) when compared with R-AS, implying high AI segmentation accuracy. Conclusions: The proposed cloud-based deep learning tool demonstrated high performance and time-efficient segmentation of implants on CBCT images. Clinical significance: AI-based segmentation of implants and prosthetic crowns can minimize the negative impact of artifacts and enhance the generalizability of creating dental virtual models. Furthermore, incorporating the suggested tool into existing CNN models specialized for segmenting anatomical structures can improve presurgical planning for implants and post-operative assessment of peri-implant bone levels.

Automated summary

This study developed a cloud-based convolutional neural network (CNN) model for automated segmentation of dental implants and attached prosthetic crowns on CBCT images. The CNN model achieved high performance and time-efficient segmentation, with high accuracy and the ability to minimize the negative impact of artifacts. This tool can enhance the creation of dental virtual models and improve presurgical planning for implants.