[ effect of intermediate flexofile golden mediums on apical transportation of the curved canals]

A large number of instruments and techniques have been introduced for preparation of canals, specially in curved canals. It's claimed that FlexoFile Golden Mediums can provide more proper canal preparations. This study aimed to evaluate the efficiency of FlexoFile Golden Mediums in decreasing apical transportation during preparation of simulated curved blocks. In this experimental study, fifty simulated resin blocks with 40°Curvature were divided in two groups. 25 canals were prepared using K-FlexoFiles and the others were prepared using K-FlexoFiles and FlexoFile Golden Mediums. Anticurvature Passive Stepback technique with pull and push motion were applied for both of the groups. The amount of resin removal from inner and outer walls of the canals was measured by using superimposed computerized pre and postoperative photographs. Results were evaluated by Mann - Whitney statistical analysis. The amount of resin removal from the inner and outer walls of the canals were assessed milimetric in 11 mm length from the apex. In the three areas of 7, 8 and 9 mm from apex, the amount of resin removal from the outer wall in the experimental group was more than the control group [P<0.05]. There was no significant difference in the other areas both in inner and outer walls between two groups. FlexoFile Golden Mediums in spite of using more instruments, had less apical transportation, and are recommended for preparation of curved canals