The evaluation of different irrigation techniques on removal of smear layer, debris, calcium hydroxide and retreatment procedures

The purpose of this study is to evaluate efficacy of different irrigation techniques on smear layer and debris removal, calcium hydroxide removal and retreatment procedures.The roots of 70 maxillary central incisors were randomly divided into 7 groups and instrumented to apical size 50 using hedstrom hand files. During instrumentation procedure 7 different irrigation techniques were used. 2 ml NaOCl were used between each instrument. For removal of smear layer 5 ml 17% EDTA for 1 min and 10 ml % 5.25 NaOCl was used. The irrigation techniques used are as follows; RinsEndo (Group 1, Duerr-Dental, Bittigheim-Bissingen, Germany), EndoVac (Group 2, Discus Dental, Culver City, CA), Canal Cleanmax (Group 3, Maximum Dental, NJ, USA), MM 1500 sonic system (Group 4, Micro Mega, Prodonta, Geneva, Switzerland) , CanalBrush (Group 5 ,Roeko, Langenau, Germany), NaviTip FX (Group 6, Ultradent Products Inc, South Jordan, UT) and manual-dynamic irrigation (Group 7). The roots were grooved longitudinally in bucco-lingual direction and splitted into two halves and each half was photographed by scanning electron microscope. The amount of the remaining smear layer on coronal, middle and apical third were recorded using a 5-step scale. Kruskal-Wallis and the Mann-Whitney U tests were used for statistical analysis. In conclusion, all irrigation techniques removed debris and smear layer better at coronal and middle third of roots and all techniques showed similar results.The roots of 74 mandibular premolars were instrumented and 72 roots were filled with calcium hydroxide paste. Two roots were left with calcium hydroxide paste as positive controls and two roots were left without paste as negative controls. Root canals (70) were divided into 7 groups according to the irrigation technique used as follows; RinsEndo, EndoVac , Canal Cleanmax, MM 1500 sonic system, CanalBrush, NaviTip FX and conventional irrigation. 10 ml 1 % NaOCl and 5 ml steril saline were used as irrigation regimen in all groups. The roots grooved longitudinally in bucco-lingual direction and split into two halves and each half was photographed with stereomicroscope. The area of the remaining calcium hydroxide paste was calculated with Image J software. Kruskal-Wallis and the Mann-Whitney U tests were used for statistical analysis. There were significant differences observed between MM1500 and all other tested groups; Conventional irrigation, Canal Clean Max, EndoVac, NaviTip FX, RinsEndo (p<0, 05) except for CanalBrush group (p>0,05). In conclusion, irrigation with MM 1500 sonic system is the most efficient irrigation technique for removing calcium hydroxide paste from the root canal.The roots of 70 maxillary central insicor instrumented to apical size 50 using hedstrom hand files and root canals were filled with gutta-percha and AH Plus sealer. Retreatment procedures was made with R-Endo and hedstrom files and finished by using 50 Hedstrom file. 2 ml 1% NaOCl used for irrigation after each enstrument changed. The irrigation techniques used were as follows; RinsEndo (Group 1), EndoVac (Group 2), Canal Cleanmax (Group 3), MM 1500 sonic system (Group 4), CanalBrush (Group 5), NaviTip FX (Group 6), and conventional irrigation (Group 7). The roots grooved longitudinally in bucco-lingual direction and split into two halves and each half was photographed with stereomicroscope. The area of the remaining root canal filling material was calculated with Image J software. Kruskal-Wallis and the Mann-Whitney U tests were used for statistical analysis. Remnants of root canal filling was found in every group. Although CanalBrush group showed the lowest results there were no significantly difference between other groups. İrrigation techniques are not efficient on retreatment procedures. Instrumentation is important on retreatment procedures.