Chelating Solutions show no Resistance of Glass Fiber Posts to the Root Dentin

Eduardo Fernandes Marques and colleagues from the Department of Endodontics, Sao Leopoldo Mandic Dental Research Center, Campinas, Sao Paulo, Brazil recently found out that the type of chelating agent used in the final irrigation of the endodontic treatment did not influence the tensile strength of the fixation system used to sealer the glass fiber posts to the intracanal dentin, as published in the European Journal of Dentistry.

Many irrigating solutions are used during chemical-mechanical preparation. These solutions would lead to a change in the collagen fibers of the dentin wall structure, besides being able to affect the calcium/phosphate ratio and interfere with the penetration of the monomer in the demineralized dentin. Consequently, the sealing process between the adhesive systems and the dental structure becomes deficient, reducing the quality and durability of direct restorations and restorations based on glass fiber posts

Therefore, the present study evaluated the influence of chelating agents on the sealer strength of glass fiber posts to root dentin.

The authors selected a total of forty mandibular premolars single canals, with complete apical root, straight, circular cross-sections. All the teeth were accessed and had the cervical third prepared with Gates-Glidden drills, then included in resin, instrumented with ProTaper Universal and the root canal obturation was carried out. After, the samples were randomly divided into 4 groups, each with 10, to test the final irrigation solutions: G1:17% EDTA; G2:10% citric acid; G3: Tetraclean and G4: saline solution (control).

After 30 days of storage at 36.5° C and 100% humidity, the post preparation was performed leaving 4 mm of apical endodontic filling. Then, a fiber-glass post previously selected was coated with ED Primer adhesive system and resin sealer Panavia, installed, and stored for 24 hours at 37°C. The samples were subjected to a tensile test with a constant speed of 1 mm/min with 2000 Kgf. The results were analyzed with the ANOVA test.

The observations revealed that there were no significant differences between the groups (p > 0.05).

Hence, the authors concluded that "the type of chelating agent used in the final irrigation of the endodontic treatment did not influence the tensile strength of the fixation system used to sealer the glass fiber posts to the intracanal dentin."