Chai J, Pang I C, Leong D, Kim J E, Torres P
Advanced Education Prosthodontics, Northwestern University Dental School, Chicago, Il.
J Prosthodont. 1993 Sep;2(3):167-73. doi: 10.1111/j.1532-849x.1993.tb00402.x.
The time required for 10 vinyl-polysiloxane impression materials to reach a viscosity of 5000 poise (Tcv) was estimated. This viscosity was selected based on previous work that suggested that an impression material might not be workable if its viscosity exceeded this limit. The effect of variations in the time of placement of the impression materials into a simulated oral-temperature environment was also studied.
The change in the viscosity of the impression materials was recorded with a viscometer at oral temperature. Impression materials were placed at either 20 seconds, 30 seconds, or 40 seconds from the start of mixing.
There were statistically significant differences in Tcv among various impression materials. Variations in placement time significantly affected the Tcv of six impression materials.
Knowledge of the viscosity change of an impression material is beneficial in the clinical selection of an impression material.
估算10种乙烯基聚硅氧烷印模材料达到5000泊粘度（Tcv）所需的时间。选择该粘度是基于之前的研究，该研究表明，如果印模材料的粘度超过此极限，可能无法使用。还研究了将印模材料放置在模拟口腔温度环境中的时间变化的影响。
用粘度计在口腔温度下记录印模材料的粘度变化。印模材料在混合开始后20秒、30秒或40秒时放置。
不同印模材料之间的Tcv存在统计学显著差异。放置时间的变化显著影响了六种印模材料的Tcv。
了解印模材料的粘度变化有助于临床选择印模材料。
