Comparison of implant abutment fit using optical microscopy versus micro computed tomography

The interface between implant and abutment has been traditionally defined by cross-sectional analysis. A new scanner using cone beam CT has become available. Purpose. This study was undertaken to compare variability of the CT technique to that of cross-sectional analysis. Materials and methods. Four implants and four abutments were connected. One specimen was scanned using a micro CT scanner at 2-micron resolution. All specimens were embedded in resin, sectioned, polished, and photographed with a digital camera on an optical microscope. Measurements were obtained using software. Results. Non-parametric tests were used. Optical microscopy estimated the gap size to be significantly larger than did micro CT. Different software yielded significantly different results. Multiple scans using micro CT yielded significantly different results. There was no detectable significant difference in means between micro CT scans and optical microscope measurements. Conclusion. There was not a detectable significant difference in variability of gap size measurements made using micro CT scanning and cross-sectional microscopy.