Table 1.

Synthesis of the included articles on XP-endo® shaper evaluated by micro-CT.

Author and year	Teeth	Method	Result
Azim et al. [10]	20 mandibular incisors	Evaluation of root canal preparation with the XP-endo Shaper and Vortex Blue instruments by micro-CT (n = 10)	XP-endo® Shaper had significantly less untouched walls (38.6%) compared to Vortex Blue (58.8%). However, the final preparation taper varied according to the anatomy of the treated tooth.
Lacerda et al. [11]	33 distal canals of mandibular molars	Evaluation of root canal preparation with the XP-endo Shaper, SAF, and TRUShape instruments by micro-CT and histologic analysis (n = 11)	There was no significant difference in the amount of unprepared surfaces between the three systems studied. The mean number of untouched areas after preparation with SAF, TRUShape, and XP-endo® Shaper was 10.92%, 17.45%, and 17.31%, respectively. Except for comparison in the apical 4 mm segments between SAF and XP-endo® Shaper, the latter showed better performance.
Versiani et al. [12]	30 mandibular incisors	Evaluation of root canal preparation with the XP-endo Shaper, iRace (R1, R2, and R3), and EdgeFile (X1 and X7) instruments by micro-CT (n = 10)	The XP-endo® Shaper, iRace, and EdgeFile system showed a similar shaping ability. The mean percentage of the untouched surface area was 9.42% (p > 0.05) for XP-endo® Shaper. There was no significant difference in the amount of untouched canal walls between groups.
De-Deus et al. [13]	10 mesial canals of mandibular molars	Micro-CT analysis of the shaping ability of the XP-endo Shaper instrument as recommended by the manufacturer and then submitting each specimen to an extra activation time of 15, 30, and 45 s (n = 10)	The extra activation times of XP-endo Shaper at working length resulted in a comprehensive root canal preparation, increasing volume and surface area of the root canal and volume of removed dentin. Preparation ranging from 31.82% of untouched surface area using the time recommended by the manufacturer at working length to 29.27%, 25.0%, and 22.74% when an extra time of 15, 30, and 45 s was used at the same length, respectively.
Zhao et al. [14]	75 mandibular molars	Evaluation of root canal preparation with the Reciproc Blue and XP-endo Shaper instruments by micro-CT (n = 35)	The XP-endo Shaper and Reciproc Blue systems were associated with a similar area of untouched canal walls after instrumentation of C-shaped root canals, in which 30.45% and 33.04% of canal walls remained untouched, respectively (p > 0.05).