Micro-CT Assessment of Hydraulic Calcium Silicate Cements for Perforating Internal Resorption in 3D-printed Tooth Replicas at Different Root Thirds: An In Vitro Study.

INTRODUCTION: Effective repair of perforating internal resorption (PIR) requires adequate defect filling; however, the influence of defect location on the filling ability of hydraulic calcium silicate cements (HCSCs) remains unclear. This micro-computed tomography (micro-CT) study evaluated Bio-C Repair (BCR), Biodentine (BD), and white MTA-Angelus (WMTA) in three dimensional-printed tooth replicas with PIR defects in different root thirds. The null hypothesis was that material performance would not differ according to defect location.

METHODS: A maxillary central incisor was instrumented to size R50 and scanned by micro-CT. PIR defects were digitally created in the apical, middle, and cervical thirds. Ninety replicas were printed and distributed by defect location (n = 30) and HCSC type (n = 10). After obturation, scans quantified cement-filling and extrusion. Surface characteristics were assessed by confocal laser scanning microscopy. Data were analyzed with Welch's analysis of variance (ANOVA) with Games-Howell post hoc and Kruskal-Wallis tests (P < .05).

RESULTS: In apical PIRs, WMTA achieved greater filling and sealing than BCR and BD (P < .05), including superior filling of the adjacent apical canal (P < .001). No differences were observed in the middle third (P > .05). In cervical PIRs, all materials showed high filling, although BD exhibited greater extrusion than WMTA (P < .01). BCR presented higher surface roughness in apical PIRs (P < .05).

CONCLUSIONS: HCSC performance in PIR repair was influenced by defect location. WMTA demonstrated more predictable apical adaptation, whereas BD showed greater cervical extrusion under simulated periodontal conditions.