A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

The aim of the present study was to compare root surface smear layer removal following topical application of EDTA and EDTA-T (Texapon). Extracted human teeth had their cementum removed and were mechanically scaled. A total of 220 root specimens were obtained and were randomly assigned to the following groups: I-saline solution (control), II-EDTA; III-EDTA-T. Groups II and III specimens were assigned to different EDTA gel concentrations: 5%, 10%, 15%, 20% and 24%. Smear layer removal score was assessed for each specimen by scanning electron microscopy. The results demonstrated that EDTA and EDTA-T gel led to a higher root surface smear layer removal when compared to the control group. The 5% EDTA gel also showed a higher smear layer removal than the 15%, 20% and 24% EDTA gels (p<0.05). No difference could be found between the different concentrations of EDTA-T gels tested (p>0.05). EDTA gels had statistically significantly lower smear layer scores than the EDTA-T gels for the 5% and 10% concentrations. The results suggested that topical application of EDTA or EDTA-T gel led to significant smear layer removal of the mechanically treated root surfaces. The addition of a detergent to the EDTA gel formula did not improve smear layer removal of the root surface.