Wylie S G, Wilson P R
School of Dental Science, University of Melbourne, Australia.
J Dent Res. 1994 Nov;73(11):1684-9. doi: 10.1177/00220345940730110301.
Pressure changes in the pulp chamber resulting from crown cementation have not been previously quantified. An experiment was designed to investigate the effect of smear layer removal on the peak pressure transmitted to the pulp chamber with crown cementation. Ten matched pairs of single-rooted premolar teeth were collected from adolescents and prepared for full-coverage crowns. The pulp tissue from each tooth was removed. One tooth from each pair had the smear layer removed with the application of 37% phosphoric acid for 30 s. The null hypothesis states that the removal of the dentinal smear layer will not change pressure in the pulp chamber resulting from the cementation. Before cementation, a hydrostatic head of pressure was used to perfuse the tooth, and the perfusion rate was recorded. Crowns were cemented with zinc phosphate cement with a seating force of 100 N. The mean peak pressures recorded were 85 Pa (SE 12 Pa) with the smear layer intact, and 194 Pa (SE 49 Pa) when the dentin was etched. The difference in the peak pressures transmitted to the pulp chamber with the two groups was significant (p < or = 0.05). A significant negative correlation was found between dentin thickness and the peak pressure transmitted to the pulp chamber (r = -0.5531, p < or = 0.01). We have shown that the pressure transmission to the pulp chamber during crown cementation can be measured. Since smear layer removal significantly influences the peak pressure, it is concluded that the pressure detected is at least partially dependent on the fluid flow through the dentin.
此前尚未对牙冠黏固导致的髓腔内压力变化进行量化。设计了一项实验，以研究去除玷污层对牙冠黏固时传递至髓腔的峰值压力的影响。从青少年中收集了十对匹配的单根前磨牙，并制备全冠。去除每颗牙齿的牙髓组织。每对中的一颗牙齿用37%磷酸处理30秒以去除玷污层。无效假设为去除牙本质玷污层不会改变黏固导致的髓腔内压力。在黏固前，使用静水压力头灌注牙齿，并记录灌注速率。用磷酸锌水门汀黏固牙冠，就位力为100 N。玷污层完整时记录的平均峰值压力为85 Pa（标准误12 Pa），牙本质酸蚀时为194 Pa（标准误49 Pa）。两组传递至髓腔的峰值压力差异有统计学意义（p≤0.05）。发现牙本质厚度与传递至髓腔的峰值压力之间存在显著负相关（r = -0.5531，p≤0.01）。我们已经表明，牙冠黏固过程中传递至髓腔的压力是可以测量的。由于去除玷污层显著影响峰值压力，得出的结论是，检测到的压力至少部分取决于通过牙本质的流体流动。
