Effect of revascularisation and apexification procedures on biomechanical behaviour of immature maxillary central incisor teeth: a three-dimensional finite element analysis study.

OBJECTIVES: This study aimed to assess the effects of revascularisation and apexification procedures on biomechanical behaviour of immature teeth using 3-dimensional finite element analysis (3D FEA). MATERIALS AND METHODS: Five 3D FEA permanent maxillary incisor models were developed from CBCT scans and available literature data: Model MT: Mature tooth, Model IT: Immature tooth (Cvek's stage 3), Model AT: Apexified tooth-mineral trioxide aggregate (MTA) apexification, Model RTB: Revascularised tooth with blood, and Model RTS: Revascularised tooth with supplementary scaffold. Using FEA, a masticatory load of 240N at 120° was simulated, and the Von Mises and maximum principal stresses within the models were evaluated. Failure index (FI) and weakening% were also calculated for each model. RESULTS: On dentinal stress analysis, model MT (96.16MPa) and IT (158.38MPa) had lowest and highest stress values, respectively. Among the experimental groups, model RTS (131.12MPa) had lower stresses than AT (136.33MPa) and RTB (133.7MPa), with no significant difference among the three. Peak dentinal stresses in all the models were observed in the cervical third of the root and near the apical opening in model IT. The extent of high dentinal stress area in model RTB and RTS was lesser than that of AT. The FI and weakening% values were highest for model AT followed by RTB and RTS, among the experimental groups. However, all these treatments strengthened an immature tooth by more than 20%. CONCLUSIONS: AT, RTB, and RTS treatments lowered the stress values and risk of fracture in immature teeth with no significant difference among the three groups. CLINICAL RELEVANCE: Stress distribution evaluation following revascularisation/apexification was essential, with potential to influence clinical decision-making. MTA apexification and revascularisation with blood clot/supplementary scaffold lowered the stresses in immature teeth, with no significant difference among the three.

Microscopic and elemental characterization of hydrated dental pulp capping agents.

Context: Characteristics of dental pulp capping agents may influence its interaction with the pulpal cells and can impact the treatment outcome. Aims: This study aims to microscopically characterize various pulp capping agents following hydration. Settings and Design: Original research. Materials and Methods: Disk-shaped specimens of five calcium silicate-based materials, i.e., mineral trioxide aggregate (MTA) Angelus, Biodentine, TheraCal LC, ApaCal ART, and Endocem MTA were prepared. After final set, the materials were immersed in 10 mL of deionized water for 14 days at 37°C. The set materials were characterized by scanning electron microscopy (SEM), X-ray energy dispersive analysis (EDX), and X-ray diffraction (XRD) analysis along with pH analysis of the storage solution using pH meter. Results: On SEM analysis, all the materials showed crystalline deposition on the cement surface with Biodentine exhibiting the most dense and homogenous microstructure. Calcium-silicate-hydrate and calcium hydroxide (CH) were observed as dark-grey and light-grey matrix material, respectively. EDX analysis revealed a high concentration of calcium. The other major elements were oxygen and carbon. The surface calcium concentration in the tested specimens was as follows: Biodentine (42.59 wt.%) > MTA Angelus (38.51wt.%) > Endocem MTA (30.24wt.%) > TheraCal LC (27.51wt.%) > ApaCal ART (22.02wt.%). On XRD analysis, all the materials exhibited peaks for tricalcium silicate and CH, after 14 days of hydration. Conclusions: The higher surface calcium level in Biodentine and MTA Angelus may enhance reparative dentin formation. The surface calcium concentration of Endocem MTA and ApaCal ART was found to be lesser than that of MTA Angelus, but with the added advantage of fast-setting property. Hence, they are potential alternative materials for vital pulp therapy.