AN ACCURATE AND SIMPLE METHOD FOR THE MEASUREMENT OF DENTAL COMPOSITEWEAR

This study describes a relatively simple mechanical technique for meas uring occlusal wear at the margin of dental restorations. The device w as essentially a custom profilometer which consisted of a linear varia ble differential transformer with its core supported by double cantile ver springs, a specially shaped stylus, a motor driven microscopic sta ge, custom computer software utilizing a colour coding to separate dif ferences in slope, and a cross-hair-shaped mouse cursor to differentia te the boundary of wear. Two sets of visual standard stone casts were evaluated. The first set consisted of 17 stone replicas of machined st eel dies and the second set consisted of five clinical casts, which ha ve been used to measure the wear of composite restorations by direct v ision. The reproducibility found when measuring the stone replicas of the machined steel dies was 2 mu m, while, for the clinical standards, it was 16 mu m.