This examination gives the insightful knowledge ofthe proceeding of smear layer abolition capability of conventional irrigationprotocol and continuous soft chelating irrigation protocol. The main principle ofshaping is to boost satisfactory irrigation, disinfection, and obturation. Accumulationof smear layer is noticed while shaping of root canal which ought to be abolishwith the help of irrigating solution.
Whole activity needed from an irrigant toreduce smear layer from dentin wall cannot be obtain by any sole irrigatingsolution. Therefore, combined application of multiple irrigating solutions is obligatoryfor optimal abolition of smear layer (5).Whereas Chloroquick solution is mix ofHEBP (a soft chelating agent) and NaOCl which can disinfect root canal as wellas reduces smear layer. Highlight of such combination of NaOCl and Etridonicacid is that the NaOCl doesn’t surrender its biological, antibacterial andtissue dissolving properties (13, 14), whereas the reduction and elimination ofthe inorganic element is done with help of HEBP (11, 12). Outcome of this current research demonstrate eradicationof smear layer was more decisive in middle and coronal third in comparison toapical third. These results are in accordance with study done by Abbott PV, Heijkoop PS et al. and numerous studies, which have proved in past thatan effective cleaning action in the middle and coronal third of the root canalseven with numerous irrigation solutions, different volume, and time (15, 16).
In coronal and middle third areas where a larger canal diameter allows betterflow of solution and more time to be in contact with dentine wall which allows thesolution to remove smear layer comprehensively. (3,16). Roleof surfactant has been discussed by many authors, in present study SmearClear,SmearOFF and Chloroquick have surfactant in the solution. Abou-Rass andPatonaiconfirmed that reduction of surface tension of endodontic solutionsimproved their flow into narrow root canals (17).
Therefore, an addition ofsurfactants to irrigation solution should improve its penetration into apicalnarrow part of root canal. In present study, SmearClear and SmearOFF despitehaving additional surfactant doesn’t show the significant removal of smearlayer in apical third when compared to control group of 17% EDTA, which doesnot have any addition surfactant. This result is in accordance with theobservationsof Lui et al. (18) and also, other studies have shown that calciumchelating ability of solution is not improved by reducing the surface tensionof the solution. Presentstudy results disply that the continuous softchelating irrigation shows thesignificantly better removal of smear layer thanconventional irrigation protocol at apical third level when 18% HEBP was usedin combination with 5.25% NaOCl (Chloroquick High).
Where 9% HEBP incombination with 3% NaOCl (Chloroquick Low) did not show any significancedifference compared to conventional irrigation protocol groups. These resultscanbe attributed to chelating agent being more time in canal and also chelatingprocedure is seen while instrumentation, unlike conventional irrigationprotocol where removal of smear layer is done only once instrumentation iscompleted (19). Paque et al. demonstrated that the accumulation of hard tissuedebris in root canals when irrigated withamalgamation of NaOCl and HEBP was significantly less than irrigationwas performed with 2.
5% NaOCl alone (20).Another advantage of this combinationis that it has better tissue dissolution capacity by keeping the hypochlorite-hypochlorous acid equilibrium towards hypochlorite (21). This combination isaffective on inorganic as well as organic part of smear layer at same time. Resultof this study is in contrast to the recently published study by AbyKuruvilla et al. where 7%malic acid wasmore effective in removing smear layer as compared to 17% EDTA and 18%etidronic acid (22). This observation may be seen because 18% etidronic acid whichis soft chelating agent was merely used in a final rinse irrigation protocol. There arevery few studies available on use of the continuous soft chelating agent forsmear layer removal.
In present study, continuous soft chelating irrigationprotocol shows promising results.