title: Influence of metal artifacts on in vivo micro-CT for orthodontic mini-implants.
abstract: This study aimed to show the effects of metal artifacts on the in vivo micro-CT of mini-implants by measuring bone volume. We drilled a hole in the cortical bone of a rat tibia and embedded a titanium orthodontic mini-implant (diameter, 1.5 mm) in the hole. Twelve individually weighed hydroxyapatite grains (HA grains) were placed around the implant either by one dentist (method 1) or separately by 12 dentists (method 2). In vivo micro-CT was used to scan the model after placement of each grain to measure increases and decreases in bone volume voxel number. The subtracted bone voxel volume increased with HA weight in both methods. Simple linear regression analysis showed a significant correlation between weight and volume in both methods (method 1: regression coefficient: 516.502, P < 0.05; method 2: regression coefficient: 4837.432, P < 0.05). Metal artifacts did not appear to influence measurements of bone volume, although further studies are required to determine the effect of thicker implants.
authors.affiliation: Department of Oral and Maxillofacial Radiology, Nihon University, School of Dentistry, Tokyo, Japan. ejima@dent.nihon-u.ac.jp
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Ejima
authors.forename: Saori
authors.initials: S
authors.lastname: Omasa
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Motoyoshi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Arai
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kai
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Amemiya
authors.forename: Hisaya
authors.initials: H
authors.lastname: Yamada
authors.forename: Kazuya
authors.initials: K
authors.lastname: Honda
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D016477:Artifacts; D015519:Bone Density; D015921:Dental Implants; D017886:Durapatite; D020007:Implants, Experimental; D016014:Linear Models; D008670:Metals; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D051381:Rats; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D014025:Titanium; D055114:X-Ray Microtomography
chemical_list: D015921:Dental Implants; D008670:Metals; D017886:Durapatite; D014025:Titanium