Spatially distributed and interconnected porous architectures for dental implants.

Abstract

Purpose: Patients with pre-existing medical conditions that impair bone integrity face challenges in dental implant success due to compromised osseointegration. This study evaluates three titanium interconnected porous architectures: the TPMS solid gyroid, TPMS sheet gyroid, and Voronoi stochastic lattice. We aim to assess manufacturability, design controllability, and cellular interactions to identify an optimal architecture that enhances cellular behavior with the potential to strengthen bone-to-implant contact.

Methods: Three porous architectures were designed and compared: the two variants of the uniform, periodic triply periodic minimal surface (TPMS) gyroid, and the random, non-uniform Voronoi stochastic lattice. The porous constructs were fabricated using selective laser melting (SLM) and evaluated using microcomputed tomography (microCT) for porosity, manufacturability, and permeability. In vitro experiments used primary bone marrow stromal cells (BMSCs) isolated from 8-week-old wild type C57BL6/J mice. These cells were seeded onto the SLM-fabricated porous architectures and evaluated for adhesion using scanning electron microscopy (SEM) and RNA extraction. Cell trajectory was profiled using fluorescent confocal microscopy.

Results: Selective laser melting (SLM) successfully fabricated all three porous architectures, with the TPMS solid gyroid exhibiting the highest manufacturing resolution, controllability, and the most uniform pore distribution. Computational fluid dynamics (CFD) analysis showed that its permeability outperformed both the TPMS sheet gyroid and stochastic Voronoi architectures. In vitro cell culturing demonstrated superior cell behavior in the TPMS solid gyroid scaffold. RNA quantification after 72 h of culture showed that cells are most adherent to the TPMS solid gyroid, demonstrating a 4-fold increase in RNA quantity compared to the fully dense (control). Additionally, cell trajectory analysis indicated enhanced cell infiltration and cellularization within the pore channels for the TPMS solid gyroid architecture.

Conclusion: This research demonstrates that inducing an interconnected porous architecture into a titanium construct enhances cellular behavior compared to a traditional dense implant. The TPMS solid gyroid architecture showed superior manufacturability, making it a promising solution to improve dental implant success in patients with compromised bone integrity.