Biomechanical and Bio-Inspired Perspectives on Root Amputation in Maxillary Molars: An FEA Study

TL;DR

This study uses computer modeling to compare the stress on molars after different root amputation procedures, finding that removing the palatal root causes the most stress.

Contribution

The study introduces a novel finite element analysis approach to assess biomechanical risks of specific root amputation types in maxillary molars.

Findings

Maximum von Mises stresses were observed at the site of occlusal force application.

Palatal root resection caused the highest stress in root dentin compared to other resections.

Stress levels in root dentin decreased in the order: palatal, mesio-buccal, disto-buccal, and intact models.

Abstract

This study aimed to evaluate the biomechanics of maxillary first molar teeth following palatal, disto-buccal, and mesio-buccal root amputation. An intact maxillary molar underwent root canal treatment using Reciproc R25 files (VDW, Munich, Germany). The canals were obturated with gutta-percha (DiaDent, Seoul, Republic of Korea) and 2Seal sealer (VDW, Munich, Germany), and the access cavity was restored with composite resin. A high-resolution CBCT scan of an intact maxillary first molar was obtained using a Planmeca Promax 3D Max system (Planmeca Oy, Helsinki, Finland) at 75 kVp and 10 mA. The acquired data were processed in 3D Slicer software (v5.8.0, BSD license, Boston, MA, USA) to segment enamel, dentin, and pulp based on pixel density variations using the three-point cloud method. A baseline intact model and three root-resected models (palatal, disto-buccal, mesio-buccal) were reconstructed in SolidWorks 2021, with resected roots simulated as being sealed with MTA. Finite element analysis was conducted in CosmosWorks to evaluate von Mises stress distribution under a 300 N static occlusal load. Maximum von Mises stresses were detected at occlusal force application sites. Among root dentin tissues, stress values ranked highest after palatal root resection, followed by the mesio-buccal, disto-buccal, and non-resected models. Conclusions: Palatal root amputation of maxillary first molars generated the highest von Mises stresses in root dentin, suggesting a higher biomechanical risk than disto-buccal or mesio-buccal resections.

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