[The size of the overlapping of the gingival margin in Class II amalgam fillings examined in the teeth and their radiographic images].

200 Class II extracted teeth provided with amalgam filling were examined. The size of the overlapping of the fillings were measured on the X-ray pictures and in the transverse section of the teeth embedded in self-cementing plastic under a stereomicroscopy by means of an ocular micrometer. The mean overlapping of the fillings was 0.52 +/- 0.44 millimeters on the teeth and 0.48 +/- 0.43 millimeters on the X-ray pictures. There was no significant difference between the values obtained by both methods. On the upper teeth [teeth: 0.64 +/- 0.50 millimeter, X-ray: 0.59 +/- 0.48 millimeters (significantly) P less than 0.001] the overlapping of the fillings was greater than on the lower ones (teeth: 0.39 +/- 0.49 millimeters, X-ray: 0.36 +/- 0.33 millimeters). The other comparisons did not show any significant difference by either method. The oro-vestibular extension of the overlapping gingival filling borders was, on the average 3.45 +/- 1.25 millimeters and amounted to 46.25 +/- 15.94% of the width of the surfaces. The percentual oro-vestibular extension of the gingival filling borders was significantly greater (p less than 0.05) on the premolars than on the molars. The gingivally overlapping filling showed also an oral and/or vestibular overlapping.