Versluis A, Douglas W H, Sakaguchi R L
Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, USA.
Dent Mater. 1996 Sep;12(5):290-4. doi: 10.1016/s0109-5641(96)80036-4.
A simple test method was developed to determine the coefficient of thermal expansion of prevailing restorative resin composites and to study the transient behavior as a function of temperature and repeated thermocycles.
Strain gauges were used to determine the thermal expansion for seven commonly used restorative resin composites by measuring the instantaneous strain along with temperature change. The temperature was measured by means of a thermocouple, the tip of which was embedded in the composite. The differences among the test groups were analyzed using ANOVA, followed by Scheffé's multiple comparisons test.
The coefficient of thermal expansion determined for the composites tested was: 22.5 +/- 1.4 x 10(-6)/degree C (Z-100), 23.5 +/- 1.4 x 10(-6)/degree C (P-50), 32.6 +/- 1.6 x 10(-6)/degree C (Herculite XR), 34.1 +/- 1.8 x 10(-6)/degree C (APH), 35.4 +/- 1.4 x 10(-6)/degree C (Conquest), 41.6 +/- 1.5 x 10(-6)/degree C (Silux Plus), 44.7 +/- 1.2 x 10(-6)/degree C (Heliomolar). The coefficient was almost linear in the considered temperature range (26-75 degrees C) for all composites (r > 0.99) and decreased with each consecutive thermocycle (p < 0.1).
Thermally induced loads, introduced into restored teeth by the mismatch of the coefficient of thermal expansion of the tooth and the restorative material, may be related to microleakage and wear problems. A highly filled hybrid composite such as Z-100 had a coefficient of thermal expansion closest to that of the tooth crown, confirming other studies which demonstrated the benefits of high filler loading in matching the properties of the dental hard tissues.
开发一种简单的测试方法，以确定常用修复性树脂复合材料的热膨胀系数，并研究其作为温度和反复热循环函数的瞬态行为。
使用应变片通过测量与温度变化相关的瞬时应变来确定七种常用修复性树脂复合材料的热膨胀。温度通过热电偶测量，热电偶尖端嵌入复合材料中。使用方差分析（ANOVA）分析测试组之间的差异，随后进行谢费尔多重比较检验。
测试的复合材料的热膨胀系数为：22.5±1.4×10⁻⁶/℃（Z - 100），23.5±1.4×10⁻⁶/℃（P - 50），32.6±1.6×10⁻⁶/℃（Herculite XR），34.1±1.8×10⁻⁶/℃（APH），35.4±1.4×10⁻⁶/℃（Conquest），41.6±1.5×10⁻⁶/℃（Silux Plus），44.7±1.2×10⁻⁶/℃（Heliomolar）。在所有复合材料的考虑温度范围（26 - 75℃）内，该系数几乎呈线性（r > 0.99），并且随着每个连续的热循环而降低（p < 0.1）。
牙齿与修复材料的热膨胀系数不匹配会在修复牙齿中产生热诱导负荷，这可能与微渗漏和磨损问题有关。高度填充的混合复合材料如Z - 100的热膨胀系数最接近牙冠的热膨胀系数，这证实了其他研究，这些研究表明高填料含量在匹配牙齿硬组织性能方面的益处。
