Objectives: A reliable laboratory wear testing is an important tool for improving composite resin material quality. For determining wear properties, a contact profilometer (PFM) has been commonly used. Recently, a digital CCD microscope (CCDM) has been launched which is easy, quick and non-contact measurement. However, difference of wear measurement of composite resins by PFM and CCDM has not been clearly confirmed.
Methods: Twenty-three wear tracts of 3 composite resins (Clearfil APX, Durafill VS, MI flow) were prepared using a modified ball-sliding wear testing machine using poppy seed and PMMA beads as 3-body media. Wear tracts were measured with a PFM (TalyScan 150), and a CCDM (VHX-1000). Maximum wear depth (MD; µm) and volume loss (VL; mm3) were measured by two systems, and evaluated with regression analysis.
Results: The MD and VL measured by PFM ranged from 15 to 230 µm and from 0.013 to 0.648 mm3, respectively. The linear regression lines of MD and VL were as follows:
MD of CCDM = 5.2 + 0.94 x MD of PFM
VL of CCDM = 0.009 + 1.02 x VL of PFM
The coefficients of determination of these lines were 0.973 and 0.995 (p < 0.01).
Conclusion: The VL measured by CCDM was almost identical to that measured by PFM. The MD measured by CCDM was in proportion to that measured by PFM. These results suggested that CCDM could be used as an alternative of PFM for measuring wear properties of composite resins.