發展不含鐵之介穩水泥做為牙科逆向封填材料的研究

Abstract

A Nobel one-step sol-gel process for adding zinc to PSC-system was developed. Different weight percentage of zinc concentrations (1%, 3%, and 5%) were added to PSC-system and analysis of the new final material was done. In this study, 5 wt% PSC-Zn significantly decreased the initial setting time of PSC Cement to 10 minutes and its final setting time to 30 minutes compared to MTA which has an initial setting time of 30minutes and a final setting time of 210 minutes. Zn is naturally abundant in the human body and is the key element for bone development and healing. PSC with different percentages of zinc added was not only non-toxic at cellular level but also has adequate mechanical properties that qualify it to be a good root-end filling material. At a preparation temperature of 800C, PSC-Zn increased the phase contents of Ca2SiO5 (C2S) and Ca3SiO6 (C3S) but decreased CaO. As a result, the setting time was shortened. It was discovered that as more weight percentage of Zn concentration was added, more unstable state was effectively created and monoclinic structure of C3S was favored to form, which increased the hydrated reaction of PSC-Zn and shortened the setting time as shown in the SEM and XRD data. The new PSC-Zn material has great sealing ability, good bio-compatibility and an ideal setting time which is believed to have magnificent potential in its application to perforation repair and retrograde filling in Apical surgery.