Corrosion of endodontic silver cones in humans: a scanning electron microscope and X-ray microprobe study

By Brady and del Rio

Date: 11/1975
Journal: JOE

Summary:  ​

Purpose: to test reactions of silver cones in clinical situations under SEM.​

  • N= 13 silver cones removed from 12 patients.​

Materials/Methods: ​

  • 13 silver points were removed from 12 patients had been in place in the root canal from 9 months to 15 years.​
  • 4 cases were asymptomatic  with no abnormalities, 1 case showed indistinct  lamina dura, 5 cases were asymptomatic with PA pathosis, 1 case had overextended cone (2.5 mm), one was underextened (2.5mm).​
  • Analyses with the scanning electron microscope (SEM) and the X-ray microprobe were performed.​
  • tissue section from a biopsy specimen of case no. 1 was examined in the Xray analyzer and under SEM.​

Most highlighted Results:  ​

  • Clinically, the cones showed surface changes ranging from dull to black and pitted.​
  • By SEM, the cones showed corrosive changes from pitting to deep circumferential erosion.​
  • Sulfur and silver were localized in biopsy tissue from the periapex that was associated with severe surface erosion.​
  • Measurement of sulfur and chlorine with the X-ray microprobe showed that these elements are present with decreasing concentrations at greater distances from the apex.​

Clinical significance:  

The results of this study indicate that silver cones undergo moderate to severe deterioration when placed as endodontic filling materials.​