METHODS: 35 maxillary incisors were endodontically prepared. A dimensionally stable silicone material was injected into the root canal space and scanned with CBCT. The root canal volume was measured using Romexis 3.0.1 R software. Replicas were carefully removed from the teeth and scanned using an extraoral laser scanner. These images were exported to the Rhinoceros software for volume measurement. The volume of each replica was also assessed using the gravimetric method. To determine the accuracy, the volume obtained from both devices was compared with the gravimetric method. Statistical analysis was done using a paired t-test. The reliability was assessed using the intraclass correlation coefficient.

RESULTS: There was no statistically significant difference between the mean volume of CBCT 27.04 ± 7.25 mm³ and the mean volume of the gravimetric method 27.87 ± 7.17 mm³ (P< 0.05). A statistically significant difference was seen with the laser scanner at 25.31 ± 6.89 mm³ and the gravimetric method at 27.87 ± 7.17 mm³ (P< 0.05). CBCT showed a good degree of agreement (ICC 0.899), while the laser scanner showed a moderate degree of agreement (ICC 0.644) with the gravimetric method. CBCT proved accurate and reliable in measuring minor volumes like the root canal space, ideally in the range of 20-25 mm³. The laser scanner presented acceptable reliability.