Biomechanical Effects of Pulpotomy Biomaterial Type and Thickness in Primary Molars: A Finite Element Analysis

Background: This study aimed to evaluate the effects of three different biomaterials (MTA, Biodentine, BioAggregate) and two base thicknesses (2 mm, 3 mm) on stress distribution in a mandibular second primary molar model treated with pulpotomy using finite element analysis. Methods: A sound mandibular second primary molar extracted for orthodontic reasons was scanned with micro-CT to create a detailed finite element model. Six models were prepared by combining three biomaterials (MTA, Biodentine, and BioAggregate) with two base thicknesses (2 mm and 3 mm). The models were evaluated under a 45° oblique occlusal loading condition, and von Mises stress distributions were analyzed in four anatomical regions: the cervical region of the mesial root, pulpal floor, furcation area, and cervical region of the distal root. Results: Compared with the 2-mm restorative configurations, the corresponding 3-mm configurations generally showed lower local stress values, particularly at the pulpal floor. However, the differences among the material and thickness combinations were relatively small. Conclusions: MTA, Biodentine, and BioAggregate exhibited similar biomechanical behavior in pulpotomized primary teeth. The 3-mm restorative configurations generally exhibited lower local stress levels than the corresponding 2-mm configurations. However, in clinical material selection, factors such as setting time, ease of application, and biocompatibility should also be taken into consideration alongside biomechanical performance.