Thickness and marking characteristics of occlusal registration strips

Abstract

T he practice of clinically marking and evaluating occlusal patterns or “high spots” has been empirical to dentistry. Dentists have used ink, silk ribbon with colorants, colored paper, plastic strips with colorants, and wax to visualize occlusal contacts. Little has been reported on the accuracy of the registration materials. Dawson’ suggested that thin silk ribbon was the most efficient method of marking interferences. Halperin et a1.2 studied marking materials to determine thickness, strength, and plastic deformation. They concluded that occlusal registration strips should be less than 21 pm thick and capable of plastic deformation. In addition, they stated that paper was a brittle material and therefore should not be used. Clinical observations revealed that commercially available occlusal registration materials produced a wide range of marks from small, sharply defined areas to broad, ill-defined smudges. 3-5 Information is needed on the variables that affect the size of the mark. Manufacturers’ designations of registration strip thickness presently are not standardized. Descriptions such as microthin, extra thin, extra-extra thin, and thick have only a rough qualititative relationship to the true strip thickness or mark size. Depending on the physical properties of a registration strip, a product may mark the actual contact area or generate a misleading smear or smudge in a noncontacting area. The purpose of this study was to investigate the relationship between registration strip thickness and area of the mark produced under dry laboratory conditions.