Composite bone–tooth constructs. (A) Tooth scaffolds composed of a dental mesenchymal (DM) cell seeded polyglycolide/poly-l-lactide (PGA/PLLA) scaffold sphere to mimic the dental papilla, and a dental epithelial (DE) cell seeded gelfoam strip to mimic the enamel organ. (B) Lattice bone scaffolds made by poly-dl-lactic-co-glycolic acid (PLGA), seeded with iliac crest–derived mesenchymal stem cells (MSCs) and grown in the rotational oxygen-permeable bioreactor system (ROBS) for 6 weeks. (C) Fabricated tooth–bone construct seeded with cells before implantation. (D) Surgical implant site before wound closure. (E) Bioengineered dental tissues that closely resembled those of naturally formed pig tooth tissues surrounded by alveolar bone. Scale bar = 100 μm. b, bone; bm, bone marrow; d, dentin; e, enamel; p, pulp; pdl, periodontal ligament.