In vitro characterization of tooth-derived and dentin-derived graft particles: Comparative analysis of particle size, mineral composition, and cytotoxicity

Background/purpose: Characteristics of grafting material influence its osteoconductive and osteoinductive properties. This study aimed to compare tooth-derived particles (TDPs) with dentin-derived particles (DDPs) with respect to particle size, demineralization behavior, elemental composition, and cytotoxicity. Materials and methods: TDP materials and DDP materials were cleaned, air-dried, ground using a Smart Dentin Grinder (KometaBio, Bergen, NJ, United States), and sorted by particle size. Both materials were demineralized with 10 % ethylenediaminetetraacetic acid (EDTA) at various time points and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy to determine the structural changes and the time required to reach 30 % residual Ca. Samples that achieved this level were subsequently evaluated for cytotoxicity according to ISO 10993-12:2021. Results: Particle size distribution was significantly different between TDPs and DDPs. The proportion of particles suitable for grafting was higher in DDPs (69.12 %) than in TDPs (55.98 %). Although the percentages of Ca and P during demineralization were slightly higher in TDPs than in DDPs, the differences were not significant. Both Ca and P contents, as well as the Ca/P ratio, decreased significantly with increasing demineralization time. Samples from both groups, adjusted to approximately 30 % residual Ca, were non-cytotoxic and met the ISO safety criteria for biological experimentation. Conclusion: DDPs have a more favorable size distribution than TDPs, requiring 17-20 min of 10 % EDTA to reach optimal 70 % Ca removal. The resulting materials are non-cytotoxic, supporting their safe and effective use as autogenous grafts.