[Observation of marginal leakage with 35SO4 =. 2. Marginal leakage of complete crowns]

The purpose of this study was to observe marginal leakage of complete crowns cemented with zinc phosphate cement and adhesive cement as determined by RI. After repeating load the samples were placed in gelatine solution with 35SO4 = labeled compound. 1. Most of complete crowns cemented with zinc phosphate cement showed remarkable marginal leakage as long as the entire length of the interface. 2. Complete crowns cemented with adhesive cement showed very little marginal leakage, a maximum depth of 0.53 mm from crown margins. 3. The repeating load test manifested proper position of crown margin, that is, the crown margin should be placed at least 1 mm far from the dowel core margin using adhesive cement. 4. The marginal distance of gaps was presumed from autoradiograms by using the regressive formula calculated from the relationship between the distance of gaps and the film density in Part 1.