| 摘要 |
<p>For the production of plaster models in dentistry, there are added to the plaster-based material at least one further component having basic characteristics and at least one further component having acid characteristics, these components being soluble in water, together with a pH indicator in order to obtain indications on the course of the process from the time of the mixing with water, the variation in the pH of the mixture being correlated with this course.</p> |
