Visual versus mechanical wear measurement of dental composite resin

SUMMARY This study compares a visual method for measuring composite wear with a relatively inexpensive mechanical technique. The visual measurements used a set of 17 graduated stone standards as the reference. Two sets of 10 unknown casts were evaluated. The first was a set of 10 stone replicas selected from the reference set in the range of 25–250 μm. The second set was composed of 10 casts of clinical restorations. The mechanical test employed a computer-controlled custom profilometer. Depth was recorded at 50 equidistant positions around the margin. A significant correlation was found (r > 0.98) between the visual and mechanical means for both measurement techniques. Mean values were equivalent for the standard casts. However, visual estimation of the clinical casts were significantly lower (61% of mechanical values) and thus not accurate for clinical use.