Lelan Li, Kun Huang, Lei Jiang, Run Chen
The biomechanical behavior of roots after lateral perforation repair was jointly influenced by perforation size, anatomical location, and loading direction. Small perforations generally maintained favorable stress conditions following post-and-core restoration, whereas large perforations, particularly those located in unfavorable anatomical regions or subjected to nonaxial loading, remained mechanically vulnerable. These findings highlight the importance of post-and-core restorative design and occlusal management in improving the long-term prognosis of perforated teeth.
INTRODUCTION: Root lateral perforation repair may restore structural continuity, but the biomechanical behavior of perforated teeth restored with post-and-core systems under different perforation sizes, anatomical locations, and functional loading conditions remains unclear.
METHODS: Three-dimensional finite element models of a maxillary central incisor and a mandibular first premolar with MTA-repaired lateral perforations and subsequent post-and-core restorations were constructed. Perforations with different sizes and anatomical locations were repaired with MTA, followed by post-and-core restoration under functional loading. Maximum principal stress and von Mises stress were evaluated in the remaining radicular dentin and perforation region.
RESULTS: Perforation size, anatomical location, and loading direction all markedly influenced stress distribution in the repaired roots. Tensile stress increased with perforation size and remained concentrated at the perforation margin and lingual cervical region. Middle-third perforations exhibited the least favorable biomechanical behavior in the maxillary central incisor, whereas lateral loading markedly increased stress in the mandibular first premolar. Most repaired models remained within the dentin tensile strength reference range; however, large perforations approaching 1.7 mm exceeded the reported threshold under unfavorable anatomical or loading conditions.
CONCLUSIONS: The biomechanical behavior of roots after lateral perforation repair was jointly influenced by perforation size, anatomical location, and loading direction. Small perforations generally maintained favorable stress conditions following post-and-core restoration, whereas large perforations, particularly those located in unfavorable anatomical regions or subjected to nonaxial loading, remained mechanically vulnerable. These findings highlight the importance of post-and-core restorative design and occlusal management in improving the long-term prognosis of perforated teeth.