측정방법에 따른 치과용 수경성 시멘트의 경화시간 = Setting time of dental water-based luting cements under various test variables

다국어 초록 (Multilingual Abstract)

Information on setting behavior of luting cements is essential to accomplish successful cementation of dental restoration. The purpose of this study is to investigate the influence of test variables on the setting time of dental water-based luting cements. Six kinds of luting cements were investigated: two zinc phosphate, two zinc polycarboxylate and two glass ionomer cements. Cements were mixed with the standard consistency for luting according to their respective manufacturer's recommendation. Setting time of cements was measured with two test apparatus (penetrating indentor and oscillating rheometer) under one of following environmental conditions (temperature/humidity); 37℃/90%, 23℃/50% and 37℃/20%. The Setting time was recorded as the time elapsed from start of mixing to the time indicated at the ISO specification (9917:1991) or when the oscillation is reduced to 95% of the original width. Setting time of luting cements was decreased with increase in temperature and decrease in humidity, and it was significantly influenced by environmental temperature and humidity. Some cements tested showed significant differences in setting time measured between indentor and rheometer under laboratory environment. Percent water loss of cements was different under various environmental conditions. This was largely arisen at the early stage of setting. Zinc Phosphate was hygroscopic under high humidity. these results indicate that working and setting time should be separately evaluated in office and oral environments, respectively. Oscillating rheometer was useful to investigate setting behavior of dental water-based luting cement. However, control of test environment and sensitivity should be considered in the rheometry.