1. The document discusses different types of abrasives used in dentistry, including finishing, polishing, and cleansing abrasives. 2. Finishing abrasives are hard and coarse to develop contours and remove irregularities, while polishing abrasives are finer and smoother surfaces. Cleansing abrasives are soft to remove softer materials from teeth. 3. Common abrasives used include aluminum oxide in coarse, medium, and fine grits applied to disks, and diamond chips impregnated in binders to form disks.