former studies have shown that the dentin wall was covered with smear layer
after mechanical shaping of the root canals with instrumentation (1,2). Disregarding
of the controversy over preserving the smear layer it has been recognized that the
smear layer itself may be infected and may protect the bacteria within the
dentinal tubules (3). Smear layer not only contains organic components but also
have inorganic component in the form of dentin chips etc (1). The penetration
of intracanal disinfectants (4) and sealers into dentinal tubules were
prevented by smear layer, which affects the final seal of the root canal
filling (5, 6, 7).
are paramount for successful debridement of the root canals with mechanical procedures
(3). There is no single effective solution available for removing both organic
and inorganic parts of the smear layer. To eliminate this smear layer mix of
sodium hypochlorite (NaOCl) and strong chelating agent such as Ethylenediaminetetraacetic
is recommended (8). It has been suggested by Crumpton et al that complete evacuation
of smear layer can be achieved by 17% EDTA for 1min followed by 5.25% NaOCl (9,12).
Till now there is no single solution which can disinfect the root canal system
as well as remove the smear layer. On the other hand the application of strong
chelating agent like EDTA for more than minute and 1ml of volume has been
reported to be associated with dentinal erosion (10,11).
(Sybron Endo, Orange, CA) is a product introduced for eliminating the smear
layer. It contains 17% EDTA solution in conjunction with a cationic (Cetrimide)
and an anionic surfactant. SmearOFF (Vista Detal Products) is Proprietary EDTA
and Chlrohexidine mix. It is prepared with combination of wetting agents and
surface modifiers for best outcomes. These solutions are used only as final
Etridonic acid which is soft chelating agent appears
to have a nominal effect on dentine walls yet can still reduce smear layer Lottanti et al. 2009. Etridonic
acid(HEBP) can be used in combination
with NaOCl without affecting its proteolytic or antimicrobial properties(13,14). In contrast to EDTA, Etridonic
acid is a weak decalcifying agent and hence cannot be used as a mere final
rinse there for it is suggested that HEBP to be mixed with NaOCl to be used as
more complete root canal irrigation solution.
(innovationsendo, India) is a combination of NaOCl and HEBP. Chloroquick High
contains 18% HEBP and 5.25% NaOCl while Chloroquick Low contains 9% HEBP and 3%
NaOCl both be mixed with surfactant tween 80 for complete root canal irrigation
solution. There for this study aims to compare the efficacy of continuous soft
chelating irrigation protocol with Chloroquick solutions to conventional
irrigation protocol on smear layer removal in coronal, middle, and apical
thirds of the instrumented root canals.