There is a lack of evidence on the chemical interaction between sealers and dentin.
The influence of irrigation on the chemical interaction between root canal sealers
and dentin was analyzed by using Fourier transform infrared spectroscopy (FTIRS) and
measurement of dislocation resistance.
Single-rooted teeth (n = 120) were instrumented with 3% NaOCl as the irrigant and divided into 4 groups
(n = 30) on the basis of irrigation protocol: group 1, 3% NaOCl, 17% EDTA, water; group
2, 17% EDTA, 3% NaOCl, water; group 3, 3% NaOCl, QMix, water; group 4, 3% NaOCl, water.
Each group was divided into 3 subgroups (n = 10) on the basis of the root canal sealer: A, epoxy resin (AH Plus); B, silicone
(RoekoSeal); C, calcium hydroxide (Sealapex). The dislocation resistance was assessed
by using push-out bond strength test. The data were statistically analyzed by three-way
analysis of variance and Holm-Sidak tests (P = .05). Dentin powder treated as per the conditioning protocols mentioned was mixed
with the sealers and analyzed by FTIRS.
A significant interaction was observed between irrigation protocol, type of sealer,
and root segment (P < .001) for AH Plus but not for RoekoSeal and Sealapex (P > .05). AH Plus showed the highest bond strength (P < .05). FTIRS showed chemical bonding between AH Plus and dentinal collagen. In groups
2 and 4, no chemical bonding was observed.
Bond strength of sealers is differentially affected by the irrigation protocol. The
epoxy resin sealer AH Plus chemically bonds to dentinal collagen. This interaction
is influenced by the irrigation protocols.