Title: In vitro evaluation of root canal wall cleanliness in primary molars after preparation with Self-Adjusting-File (SAF) or Mtwo NiTi-instruments and final irrigation
Abstract: Aim In vitro evaluation of cleanliness of root canal walls of primary molars after preparation with the Self-Adjusting-File and Mtwo-instruments and final irrigation with citric acid and sodium hypochlorite.
Materials and methods Study Design: In 23 matched pairs, teeth were prepared either with SAF or with Mtwo NiTi-instruments, and final irrigation was performed with 2 mL citric acid and 4 mL NaOCl. Roots were split longitudinally, SEM-images were taken, and smear layer was evaluated by two blinded observers using a four-grade score. Statistical evaluation was performed with Mann-Whitney-U-Test and Wilcoxon Signed Rank Test (P<0.05).
Results No significant difference between SAF and Mtwo (P=0.9454) was observed. Overall removal of the smear layer was significantly better in the coronal part of the root canal than in the apical one (P=0.0004393). Mtwo showed no significant difference in cleanliness when comparing the coronal and apical part of the root canal (P=0.1089), whereas SAF cleaned the coronal part of the root canal significantly better than the apical part (P=0.00108).
Conclusion None of the two instruments was superior concerning cleanliness in root canals of primary molars. Both show good cleaning ability when using an irrigation protocol with citric acid and sodium hypochlorite.