A Microscopic Comparison of the Residual Smear Layer Remaining in Root Canals, after Rotary Instrumentation with and without a Viscous Chelator

Gastón Zamora; Rodrigo Fuentes; Erika Peschke & Felipe Nenen

Summary

Viscous chelators are used to help the instrumentation of narrow root canals, however, they could contribute to greater accumulated smear layer. The aim of this study was to compare the smear layer generated following instrumentation with or without the application of a viscous chelator. 39 inferior incisors were instrumented with Protaper® and divided into three groups. Irrigation in group A and B was performed after each instrument was changed, irrigation was realized as follows: EDTA 17% (1 minute), then NaOCl 5.25% and a final rinse with physiologic saline solution. Also in group A, a viscous chelator was used between each file. Group C irrigation was performed only with physiologic saline solution. Three teeth were not instrumented and irrigated (negative control). The roots were then longitudinally grooved and sectioned by thirds for microscopic evaluation. The detritus score obtained was compared statistically using non-parametric test (p<0.05). In each third very low values of smear layer were found, and were the same in all three groups. In contrast, in the apical third of the groups A and C there was significantly more smear layer than in group B.

KEY WORDS: viscous chelator, smear layer, rotary instrumentation.

How to cite this article

ZAMORA, G.; FUENTES, R.; PESCHKE, E. & NENEN, F. A Microscopic comparison of the residual smear layer remaining in root canals, after rotary instrumentation with and without a viscous chelator. Int. J. Odontostomat., 5(2):165-170, 2011.