The efficacy of laser, ultrasound and self-adjustable file in removing smear layer debris from oval root canals following retreatment: A scanning electron microscopy study

A. Keles, A. Kamalak, C. Keskin, M. Akçay, I. Uzun

Australian Endodontic Journal 2016; 42(3):104-111



This study aims to compare the efficacy of different irrigation activation methods to remove smear layer and debris from oval-shaped root canals following retreatment. Ninety mandibular canines with oval-shaped root canals were selected. Retreatment was performed with R-Endo retreatment files. The samples were randomly divided into six groups (n = 15). Groups were assigned according to agitation technique: R-Endo with classic irrigation, with self-adjustable file, with passive ultrasonic irrigation, R-Endo + Er:YAG, R-Endo + PIPS and R-Endo + Nd:YAG. Compared with the classic irrigation (R-Endo + CI) group, all other groups were more successful in reducing smear layer and debris (P < 0.05). The least amount of residual smear layer and debris was detected in the Er:YAG laser group (P  < 0.05). Additional use of different agitation methods contributes to removal of debris and smear layer following root canal filling removal with rotary instruments; however, none of the techniques tested render root canal walls completely free of smear layer or debris.  


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keles debris retreatment


Additional Info

  • ReDent Nova’s note:

    This research did not use the advised clinical protocol for retreatment with the self-adjusting file, including the use of a guttapercha softener (Chloroform or other), followed by 4 minutes of operation of the SAF with a combination of NaOCl and EDTA irrigants.

    Instead, the research used the SAF for only 2 minutes (1 minute with EDTA, another minute with NaOCl) and did not use any guttapercha softener. Had the advised clinical protocol been used, the results would have likely been improved.

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