Biocompatibility and cytotoxicity assessment of 3D-printed orthodontic aligners

Background/purpose: The development of 3D-printed orthodontic aligners offers an alternative to conventional thermoformed aligners, reducing material waste and production time. However, concerns regarding biocompatibility and cytotoxicity remain. This study evaluates the cellular response of human periodontal ligament (PDL) cells and MG63 osteoblast-like cells to Graphy and LuxCreo 3D-printed resins, assessing their potential impact on orthodontic treatment and bone remodeling. Materials and methods: PDL and MG63 cells were cultured and exposed to extracts from Graphy and LuxCreo resins. MTT assays measured cell viability at 24, 48, and 72 h, while phase-contrast microscopy analyzed cell morphology, adhesion, and confluency. Statistical comparisons were performed using ANOVA with Bonferroni post-hoc testing. Results: Graphy-treated cells exhibited high viability and confluency, demonstrating progressive adaptation and proliferation. In contrast, LuxCreo-treated cells showed lower initial viability, with poor adhesion and slower recovery. MG63 cells, in particular, exhibited reduced osteoblast compatibility with LuxCreo, indicating potential limitations for bone remodeling applications. Conclusion: Graphy demonstrated better biocompatibility and osteoblast support, making it a more suitable material for orthodontic applications. LuxCreo showed early cytotoxic effects, suggesting the need for surface modifications to enhance cellular response. Further research is required to optimize 3D-printed aligner materials for long-term intraoral use.