Efficiency of final irrigation of root canal in removal of smear layer

Abstract

Introduction A smear layer forms on the root canal walls as the consequence of root instrumentation. The smear layer formed in such a way considerably influences the quality of root obturation and endodontic treatment outcome. Objective The aim of this study was to ultrastructurally analyze the surface of intracanal dentine after removal of the smear layer by the solution of doxycycline, citric acid and detergent Tween-80 (MTAD). Methods The study involved 60 single-rooted, extracted, human teeth divided into four groups. All samples were instrumented by a step-back technique and manual K-files, and rinsed during instrumentation by 2% CHX and H2O2. The first group of samples was exclusively rinsed by CHX and H2O2; in the second group, besides using CHX and H2O2, MTAD solution was used for the final irrigation. The samples which were rinsed by distilled water (+ control) and the samples rinsed by 5.25% NaOCl and 17% Na EDTA (-control) served as control groups. All samples were observed under the scanning electronic microscope JEOL-JSM-5300. The coronary, middle and apex thirds of the radix region were analyzed. Results The obtained results of the SEM analysis showed that the application of 2% chlorhexidine and hydrogen peroxide did not give clear dentine walls, and the smear layer could not be removed completely. The application of the same combination (CHX and H2O2), added by the final MTAD irrigation solution, led to the efficient removal of the smear layer, while the morphological structure of dentine surface remained unchanged. Statistical analysis showed that canal walls in the experimental group with MTAD as the final irrigation were significantly clearer compared to the control group (p lt 0.001). Conclusion Based on the obtained results, it can be concluded that MTAD is an efficient solution for the final irrigation of the canal system.

Uvod Razmazni sloj koji se stvara na zidovima kanala korena zuba posledica je instrumentacije kanala. On značajno utiče na kvalitet opturacije kanala i krajnji ishod endodontskog lečenja. Cilj rada Cilj istraživanja je bio da se ustanovi stepen efikasnosti rastvora doksiciklina, limunske kiseline i deterxenta Tween-80 (poznate pod nazivom MTAD) kao završnog irigansa u uklanjanju razmaznog sloja s površina intrakanalnog dentina. Metode rada Ispitano je 60 jednokorenih ekstrahovanih humanih zuba, podeljenih u četiri grupe. Svi uzorci su instrumentirani tehnikom step-back i ručnim K-turpijama, a tokom instrumentacije ispirani dvoprocentnim hlorheksidinom (CHX) i tropostotnim vodonik-peroksidom (H2O2). Prva grupa uzoraka je ispirana isključivo sa CHX i H2O2, dok je za završnu irigaciju uzoraka druge grupe korišćen i rastvor MTAD. Svi uzorci su posmatrani na skening elektronskom mikroskopu JEOL-JSM-5300. Ultrastrukturno su analizirane koronarna, srednja i apikalna trećina korenske regije. Rezultati Primenom samo CHX i H2O2 kao irigansa ne dobijaju se čisti dentinski zidovi, a razmazni sloj sa zidova nije potpuno uklonjen. Istom kombinacijom irigansa koja je dopunjena rastvorom MTAD za završno ispiranje razmazni sloj se efikasno uklanja, a morfološka struktura dentinske površine se ne menja. Statistička analiza je pokazala da su zidovi kanala uzoraka ispiranih i sa MTAD značajno čistiji nego kod uzoraka kontrolne grupe (p lt 0,001). Zaključak Na osnovu rezultata istraživanja može se zaključiti da je MTAD bio najefikasniji rastvor za završnu irigaciju kanalnog sistema korena zuba.