Restorative Dentistry, University Dental School and Hospital, Wilton, Cork, Ireland.
J Oral Rehabil. 2010 Apr;37(4):278-82. doi: 10.1111/j.1365-2842.2009.02045.x. Epub 2009 Dec 29.
The effect of pre-heating resin composite on pre-cured viscosity and post-cured surface hardness was evaluated. Groups of uncured specimens were heated to 60 degrees C and compared with control groups (24 degrees C) with respect to viscosity and surface hardness. Mean (SD) viscosities of the pre-heated specimens (n = 15) were in the range of 285 (13)-377 (11) (Pa) compared with 642 (35)-800 (23) (Pa) at ambient temperature. There was a statistically significant difference between the two groups (P < 0.001). Mean (SD) Vickers microhardness (VHN) of the pre-heated group (n = 15) was 68.6 (2.3) for the top surface and 68.7 (1.8) for the bottom surface measured at 24 h post curing (specimen thickness = 1.5 mm). The corresponding values for the room temperature group were 60.6 (1.4) and 59.0 (3.5). There was a statistically significant difference between corresponding measurements taken at the top and bottom for the pre-heated and room temperature groups (P < 0.001). There was no significant difference between top and bottom measurements within each group. Pre-heating resin composite reduces its pre-cured viscosity and enhances its subsequent surface hardness. These effects may translate as easier placement together with an increased degree of polymerization and depth-of-cure.
研究了预加热树脂复合材料对预固化粘度和后固化表面硬度的影响。将未固化的样本分为几组，加热至 60°C，并与对照组（24°C）进行比较，以测量粘度和表面硬度。预热组（n=15）的平均（SD）粘度范围为 285（13）-377（11）（Pa），而环境温度下的对照组为 642（35）-800（23）（Pa）。两组之间存在统计学上的显著差异（P<0.001）。预热组（n=15）在固化后 24 小时测量的顶部表面的平均（SD）维氏硬度（VHN）为 68.6（2.3），底部表面为 68.7（1.8）。室温组的相应值分别为 60.6（1.4）和 59.0（3.5）。预热组和室温组的顶部和底部测量值之间存在统计学上的显著差异（P<0.001）。每个组内的顶部和底部测量值之间没有显著差异。预加热树脂复合材料降低了其预固化粘度并提高了随后的表面硬度。这些效果可能表现为更容易放置，聚合度和固化深度增加。
