A Robust Model to Test the Accuracy of Cone Beam Computed Tomography Linear Measurements

Abstract

In planning for placement of dental implants in edentulous mandibles, the accuracy of the linear measurements of the cone beam computed tomography (CBCT) has been questioned. This study used a digital caliper as the gold standard to which linear measurements taken from CBCT were compared. Customized aluminum screws, 2.8 mm in diameter and 11-12 mm in length, were used as dental implant analogues in the canine, premolar, and molar regions in completely edentulous synthetic polyurethane mandibles. A 2 mm aluminum wire was used as the mandibular canal. A total of 240 readings by the digital caliper and the CBCT were recorded for the screws length and diameter, mandibular canal wire diameter, and the distance from the apices of the screws to the superior border of the mandibular canal wire. The statistical analysis was performed using the paired sample T test, with a p value of .05 considered statistically significant. Statistically significant differences between the digital caliper readings and those of the CBCT were recorded in the canine, premolar and molar regions where all the over-and under-estimations did not exceed half a millimeter. The statistically significant discrepancies found in the linear measurements of the CBCT were less than 1 mm, and therefore did not exclude the CBCT from being a beneficial tool in the planning for dental implant placement. However, it is important to note that the results of this study and cannot be generalized to all CBCT machines as they are not created equal by different manufacturers.