2013 Volume 76 Issue 2 Pages 83-88
We investigated the repeatability of contact area measurements using a tooth contact analyzing device which can quantitatively measure occlusal contact area and the number of contact points. A kneaded sample of silicon was weighted with a 1 kg steel ball fixed on a constant loader. We made seven silicon samples with steel balls of seven different sizes, and recorded the contact area of the samples at thicknesses of less than 4 μm, less than 9 μm and less than 29 μm using the BiteEye® tooth contact analyzing device. The measurements were made twice on the same day. Two measurement values were assessed by the intraclass correlation coefficients (ICC), and the mean differences (MD) and 95% limits of agreement (95% LOA) were obtained by the Bland-Altman method. We then evaluated the repeatability of repeated measurements.
The ICCs were greater than 0.9 for all of the repeated measurements for each thickness of silicon sample. The MDs were all essentially zero (-0.005 mm2, -0.002 mm2 and 0.011 mm2 for the silicon thicknesses of less than 4μm, less than 9μm and less than 29μm, respectively). The 95% LOAs were -0.083 to 0.070 mm2, -0.054 to 0.051 mm2, and -0.082 to 0.105 mm2 for the three thicknesses, respectively. We found that the repeatability of the measurements using the tooth contact analyzing device was very high.
