Stevanović R
Stomatol Glas Srb. 1989 Jun-Aug;36(3):175-84.
An important question in conservative dentistry is whether in direct contact of calcium hydroxide paste and phosphate cement the neutralization of pH calcium hydroxide occurs and how it can be prevented. Chemical investigations performed in vitro conditions (in the test tube) concerned 3 groups, each of which had 12 samples. In the A group (control group) calcium hydroxide paste was put at the bottom of the test tube and ZOOK paste and phosphate cement layer were put over it; in the B group, Tubulitec base in 2 layers was applied over calcium hydroxide cement and then the phosphate cement; and in the C group, the calcium hydroxide paste and phosphate cement were put in the test tube in direct contact. Within 12 weeks, after 7 days, the 3 samples were investigated (1 in each group). Contrary to expectations the results showed that in direct contact of calcium hydroxide paste and phosphate cement no change occurred in pH calcium hydroxide, and that its average value was 12.70. Further were there was no statistically significant difference in values of pH calcium hydroxide paste among the A, B and C groups. On the basis of these studies and in the opinion of other authors, it may be concluded that, although there was no decrease in pH calcium hydroxide in direct contact of calcium hydroxide paste and phosphate cement, it should be necessary to make the mutual isolation of these materials; in practice this is most efficiently done on two-layer Tubulitec base.
保守牙科领域的一个重要问题是，氢氧化钙糊剂与磷酸锌水门汀直接接触时，氢氧化钙的pH值是否会发生中和以及如何预防。在体外条件下（在试管中）进行的化学研究涉及3组，每组有12个样本。A组（对照组）将氢氧化钙糊剂置于试管底部，在其上方放置ZOOK糊剂和磷酸锌水门汀层；B组在氢氧化钙水门汀上涂抹两层Tubulitec基底，然后再涂抹磷酸锌水门汀；C组将氢氧化钙糊剂和磷酸锌水门汀直接放入试管中接触。在12周内，7天后对3个样本进行研究（每组1个）。与预期相反，结果表明，氢氧化钙糊剂与磷酸锌水门汀直接接触时，氢氧化钙的pH值没有变化，其平均值为12.70。此外，A、B、C组氢氧化钙糊剂的pH值之间没有统计学上的显著差异。基于这些研究以及其他作者的观点，可以得出结论，虽然氢氧化钙糊剂与磷酸锌水门汀直接接触时氢氧化钙的pH值没有降低，但仍有必要使这些材料相互隔离；在实践中，最有效的方法是在两层Tubulitec基底上进行。
