Aims: To compare the shaping efficiency of the XP-endo Shaper with or without glide path preparation with sequenced Scout Race files in J-shaped resin blocks
Material and Methods: Forty simulated J-shaped root canals were classified into two groups (n=20). While the root canals were shaped with XPS after a glide path was created with Scout Race files in Group 1, the same procedures were done without the glide path preparation in Group 2. The pre-and post-instrumentation images were taken and superimposed. Transportation value (TV), centering ability (CA) and the total amount of resin removed (TRR) was calculated by using the obtained images with Adobe Photoshop CS5 software. These parameters were calculated based on 18 reference points (9 inner/9 outer walls) with 1-mm intervals according to 3 sections (coronal, middle, and apical of the canals). The data were analyzed with Kruskal-Wallis and then Dunn's multiple comparison tests (p ≤ 0.05).
Results: More resin was removed in Group 2 apical and coronal sections than in Group 1 (p=0.036). In Group 2, a higher transportation value was obtained in apical and middle sections compared to Group 1 (p<0.001). Group 1 showed a higher centering ratio in apical and middle sections than in Group 2 (p<0.001). The centering ability of the instruments was decreased in the curvature part (middle section) of the canals.
Conclusions: Within the limits of this study, glide path preparation using Scout Race instruments improved the shaping ability of XPS instrument by leading to less transportation and maintaining centering ability.