VISUAL VERSUS MECHANICAL WEAR MEASUREMENT OF DENTAL COMPOSITE RESIN

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 r eplicas selected from the reference set in the range of 25-250 mu m. T he second set was composed of 10 casts of clinical restorations. The m echanical test employed a computer-controlled custom profilometer. Dep th was recorded at 50 equidistant positions around the margin. A signi ficant correlation was found (r > 0.98) between the visual and mechani cal means for both measurement techniques. Mean values were equivalent for the standard casts. However, visual estimation of the clinical ca sts were significantly lower (61% of mechanical values) and thus not a ccurate for clinical use.