[Behavior of Zn-phosphate cement in parafunctional conditions. 2. Wear resistance of Zn-phosphate cement]

The paper deals with the phenomenon of complex stress of the Zn-phosphate cement when slope specimens are loaded. In a 5 degree slope the horizontal component was only 0.7% whereas this value began to increase up to 45.3% when the slope was 40 degrees. It is of interest that in the slant specimens the significant part of the total force referred to horizontal component, particularly expressed in parafunctions, which speaks for the unfavourable stress type suffered by specimen slope. The second part of the experiment revealed the degree of wear of Zn-phosphate cement parafunctional activities. The value of 1800 which presents the number of contacts realized by a patient with parafunctions only in the course of daily action of occlusive dental surfaces, was selected as the maximal number of pulses. The following was established: with the increase of pulses the degree of wear was also increased; the wear was more expressed in the mobile specimen; the degree of wear of the mobile specimen was not a linear function of the number of pulses contrary to the fixed one in which a linear dependence was observed.