[Investigation of castability and layered structure on margin of titanium cast crown]

Previous studies on dental applications of pure titanium were mainly focused on its mechanical properties rather than its clinical aspects. The purpose of this study was to evaluate the margin castability and mechanical properties of C. P. titanium for better understanding of its suitability for clinical application. To simulate the crown margins, flat wax patterns, which had two different margin thicknesses, i.e., 20 and 40 degrees sharp edges respectively, were used. These patterns were cast using two casting systems, centrifugal and pressure systems. There were statistically significant differences between the samples made from the two types of patterns in terms of cast deficiency at the margins observed with a light microscope and the increased length of the margins measured with a video micrometer, but not between the samples made with the two different systems. Both the thickness of layered structures measured by a metallurgical light microscope and the micro-hardness by a Dynamic Hardness Tester were lowest at the apex of the margins in all samples. These observations were more evident among 20 degree samples than 40 degree samples. The layered structures were different among the casting systems. In conclusion, pure titanium is suitable for clinical application as restorative material when used appropriately.