Room: AAPM ePoster Library
Cone beam computed tomography (CBCT) imaging is commonly used in treatment planning for dental implant placement. Metal artifacts produce image deterioration via bright streaks and loss of gray values in the vicinity of metallic structures, such as amalgams and stainless-steel crowns. The aim of the study is to determine the impact of progressively increasing metal artifacts on the measurement accuracy of commonly evaluated points in implant treatment planning.
Holes (1 mm in diameter) were drilled into porcine mandibles located 3, 6, and 9 mm from the alveolar crest on the buccal and lingual surfaces and filled with gutta percha. Repeated images were taken using a Carestream 9300 dental CBCT machine, with progressively increasing metal restorations (amalgams and stainless-steel crowns) ranging from 0 to 8 restorations per jaw using dentoalveolar (80 kV, 5 mA, 12.0 s, 0.2 mm voxel spacing) and full-arch (90 kVp, 4 mA, 6.2 s, 0.18 mm voxel spacing) fields of view. The measurement between gutta percha points (buccal to lingual) on the mandible was performed using calipers to establish “truth”. The same measurements were made by manually selecting identical points on the CBCT images, and compared with “truth” to estimate the measurement accuracy with increasing number of restorations.
Comparison of measurements made using calipers and baseline CBCT (with no metal artifact) demonstrated differences up to 1.7 mm. Comparison of baseline CBCT images with those containing increasing metal artifact showed measurement errors up to 0.7 mm, with no clear pattern of increasing errors.
There is a variation of up to 1.7 mm between measurements made with calipers and made on CBCT images. While this measurement inaccuracy may be clinically relevant, it is not affected by metal artifact due to increasing numbers of amalgam restorations or stainless-steel crowns.