Shear bond strength of eugenol- and non-eugenol-based endodontic sealers to gutta-percha and dentin: An in vitro study.
OBJECTIVE
a) To evaluate the bond strength of eugenol- and non-eugenol-based endodontic sealers to gutta-percha and dentin and b) To make a comparative evaluation of the bond strength of sealers to gutta-percha and dentin.


METHODS
Seventy-two specimens were used in this study, which was divided into two groups - group I consisting of 36 freshly extracted human molars with 2 mm coronal cut surface; and group II consisting of gutta-percha disks of 10 mm diameter and 2 mm thickness embedded in 36 plaster of Paris specimens. Group I was further divided into three subgroups: subgroup 1, subgroup 2, and subgroup 3, consisting of 12 teeth each; and group II was further divided into three subgroups: subgroup 1, subgroup 2, and subgroup 3, consisting of 12 plaster specimens each. Each subgroup consisted of two materials each, which were placed in 5 mm long sections of polyethylene tubing and were then placed on coronal 2 mm cut surface of human molars; likewise subgroup 1, subgroup 2, and subgroup 3 of group II consisted of two materials each, which were also placed in 5 mm long sections of polyethylene tubing and then placed on gutta-percha disks 10 mm in diameter and 2 mm in thickness, which were embedded in the plaster specimens. After the materials were set, the specimens were subjected to test for shearing bond strength using a universal testing machine (Instron).


METHODS
Mann-Whitney U test.


RESULTS
Group I, i.e., zinc oxide eugenol sealers, showed more bond to gutta-percha than to dentin, in which subgroup 2b, endomethasone, showed the maximum bond. Group II, i.e., non-zinc oxide eugenol sealers, showed more bond to dentin than to gutta-percha, where the maximum bond was shown by subgroup 3b, EndoRez.


CONCLUSIONS
Under the circumstances of this in vitro study, all the six endodontic sealers had significant differences in terms of shear bond strength to gutta-percha and dentin.
Department of Conservative Dentistry and Endodontics, A. B. Shetty Memorial Institute of Dental Sciences, Mangalore, India.
Shibu Thomas
ST
Mathew
Mithra N
MN
Hegde