Imaging evaluating of the implant/bone interface-an in vitro radiographic study

To analyze the diagnostic accuracy of conventional and digital radiographic images and the impact of digital filters in evaluating the bone-implant interface.

Titanium implants were inserted into 74 fresh bovine ribs blocks, 37 fitting tight to the bone walls (simulating the existence of osseointegration) and 37 with a gap of 0.125 mm (simulating a failure in the osseointegration process). Periapical radiographs were taken with conventional film and two phosphor plate systems [VistaScan^® (Dürr Dental, Bietigheim-Bissingen, Germany) and Express^® (Instrumentarium, Tuusula, Finland)]. Digital radiographs were investigated with and without enhancement filters. Three blinded examiners assessed the images for the presence of juxtaposition in the bone-implant interface using a five-point Likert scale. Sensitivity, specificity and the area under the receiver-operating characteristic curve (AUC) and its 95% confidence interval (CI) were calculated for each variable. Intraexaminer and interexaminer agreements were analyzed using Kendall's concordance test.

Intraexaminer and interexaminer agreements were >0.80 for both digital and conventional images. Conventional radiographs (AUC = 0.963/CI = 0.891 to 0.993) and digital images with high enhancement filters such as Caries2 (AUC = 0.964/CI = 0.892 to 0.993), Endo (AUC = 0.952/CI = 0.875 to 0.988) and Sharpen3 (AUC = 0.894/CI = 0.801 to 0.954) showed the greatest accuracy for evaluating the bone-implant interface. Original images from both digital systems and the further enhancement filters tested showed low sensitivity for the diagnosis task tested.

Conventional radiographs or digital radiographs with high-pass filters could help enhance diagnosis on implant-bone interface.