Authors: Negm MM.
Title: Filling root canals with silver-percha cones: a clinical study.
Journal: Oral Surg Oral Med Oral Pathol
Date: Jan 1983
Citation: 55(1):81-5
Category: Obturation
Evidence-based Ranking: 2
Purpose/Objective: To evaluate silver-percha as a root canal filling material comparing the percentage of success with that of silver cones. Also, to determine what role the gutta percha layer of the silver percha plays by comparing discoloration, tarnish and corrosion in relation to their clinical use.

Materials and methods: The study had 2 groups of patients, first group with 64 teeth obturated with silver percha and the second group with 52 teeth obturated with silver cones. The root canal sealer used was AH-26. Patients were recalled for clinical and radiographic examination 1 and 4 weeks after the treatment. The temporary fillings were then replaced with permanent restorations and the patients were recalled at 6-month intervals. For the operation to be recorded as clinically successful, the tooth must have a negative history of pain and absence of tenderness to percussion. To be radiographically successful, there must be negative periapical radiographic findings. A tooth that demonstrated any clinical or radiographic evidence of pathologic change was classified a failure. Permanent fillings were removed and the master cones were pulled out of the canals. The cones were then examined for tarnish, corrosion and surface discoloration. A case was a failure when the master cone exhibited any degree of surface discoloration

Results: Only 5 cases were listed as unsuccessful on the basis of clinical and radiographic evidence. When the findings were evaluated from the tarnish and corrosion standpoint, 7% of the 1st group showed surface discoloration at the apical thirds of the silver cones. In the 2nd group (silver cones), 70% exhibited different degrees of tarnish and corrosion.

Conclusions: The findings emphasize the importance of the gutta-percha layer for the success of any root canal treatment with silver cones, with regards to tarnish and corrosion.

ReviewerÂ’s comments: This article supports the use of gutta-percha in conjunction with silver points; and consequently having gutta percha itself replace silver points as the root canal filling material of choice to avoid tarnish and corrosion (and subsequent leakage) of the filling material.