Digital volume tomography in the diagnosis of peri-implant defects: an in vitro study on native pig mandibles.
BACKGROUND
The aim of this study of native pig mandibles was to investigate the accuracy and quality of the representation of peri-implant defects by intraoral radiography (IR), panoramic radiography (PR), computer tomography (CT), and digital volume tomography (DVT).


METHODS
The examination was carried out on 19 native pig mandibles. In the toothless sections of the mandibles, one or two implants were inserted. Following the standardized preparation of peri-implant defects (11 each of dehiscences, fenestrations, and 2- to 3-walled intrabony defects), IR, PR, CT, and DVT were performed. The peri-implant defects were measured using appropriate software on the digitized IR and PR image programs. As a control method, the peri-implant bone defects were measured directly using a reflecting stereomicroscope with measuring ocular. The statistical comparison between the measurements of the radiographic scans and those of the direct readings of the peri-implant defects was performed with Pearson's correlation coefficient. The quality of the radiographic scans was determined through the subjective perception and detectability of the peri-implant defects by five independent observers.


RESULTS
In the DVT and CT scans, it was possible to measure all the bone defects in three planes. Comparison with the direct peri-implant defect measurements yielded a mean deviation of 0.17+/-0.11 mm for the DVT scans and 0.18+/-0.12 mm for the CT scans. On the IR and PR images, the defects could be detected only in the mesio-distal and cranio-caudal planes. In comparison with the direct measurements of the peri-implant defects, the IR images revealed a mean deviation of 0.34+/-0.30 mm, and the PR images revealed a mean deviation of 0.41+/-0.35 mm. The quality rating of the radiographic images was highest for the DVT scans.


CONCLUSIONS
Overall, the CT and DVT scans displayed only a slight deviation in the extent of the peri-implant defects. Both radiographic imaging techniques permitted imaging of peri-implant defects in three planes, true to scale, and without overlay or distortion. The DVT scans showed the best imaging quality.
Mengel
Reiner
R
Department of Periodontology, Philipps University, Marburg, Germany. mengel@mailer.uni-marburg.de
Kruse
Björn
B
Flores-de-Jacoby
Lavin
L
D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging* / Q000209:etiology; D000818:Animals; D003758:Dental Implantation, Endosseous / Q000009:adverse effects; D015921:Dental Implants / Q000009:adverse effects*; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000000981:diagnostic imaging; D011861:Radiography, Dental / Q000379:methods*; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic; D013529:Surgical Wound Dehiscence / Q000000981:diagnostic imaging; D013552:Swine; D014057:Tomography, X-Ray Computed
D015921:Dental Implants