Histological and immunohistochemical studies of tissue engineered odontogenesis

Abstract

The successful regeneration of complex tooth structures based on tissue-engineering principles was recently reported. The process of this regeneration, however, remains poorly characterized. In this study, we have used histochemistry to examine the regeneration process of tissue engineered teeth in order to determine the cell types that give rise to these engineered tooth structures. Porcine third molar tooth buds were dissociated into single-cell suspensions and seeded onto a biodegradable polyglycolic acid polymer scaffold. Following varying periods of growth in rat hosts, the specimens were evaluated by histology and immunohistochemistry. Aggregates of epithelial cells were first observed 4-6 weeks after implantation. These aggregates assumed three different shapes: a natural tooth germ-like shape, a circular shape, or a bilayer-bundle. Based on the structure of the stellate reticulum in the dental epithelium, the circular and bilayer-bundle aggregates could be clearly classified into two types: one with extensively developed stellate reticulum, and the other with negligible stellate reticulum. The epithelial cells in the circular aggregates differentiated into ameloblasts. The continuous bilayer bundles eventually formed the epithelial sheath, and dentin tissue was evident at the apex of these bundles. Finally, enamel-covered dentin and cementum-covered dentin formed, a process most likely mediated by epithelial-mesenchymal interaction. These results suggest that the development of these engineered teeth closely parallels that of natural odontogenesis derived from the immature epithelial and mesenchymal cells.

Tooth Organ Engineering: Biological Constraints Specifying Experimental Approaches

“…6) were not used to shape the forming organ but either to maintain cells together and work with high cell density or to retain signaling molecules involved in stimulating morphogenesis and/or cell differentiation (Griffith & Schwartz, 2006;Honda et al, 2005;Huang et al, 2010;Sumita et al, 2009). The level of signaling in the mesenchyme was recognized as a potentially limiting factor in tooth engineering (Hu et al, 2006a;Nait Lechguer et al, 2009).…”

Midkine expression correlating with growth activity and tooth morphogenesis in odontogenic tumors

“…These epithelial and mesenchymal differentiations do not independently occur, but are induced through the intermediary interaction between odontogenic epithelial and ectomesenchymal components. [7,8] Therefore, tooth germ is regarded as one of the good morphogenetic models for epithelial-mesenchymal interactions.…”

Stem Cell Regenerative Therapy in Oral and Maxillofacial Region: A Systematic Review.

“…They confirmed bioengineered rat teeth grown in 12 weeks with Poly Lactic co glycolic 1635 acid (PLGA) and Poly glycolic acid (PGA) scaffold. Honda et al 2005 (32) developed tissue engineered teeth, when implanted into omentum of rat utilizing porcine tooth bud cells and PGA fiber engage scaffold that reminds of the model of odontogenesis. Young et al 2005 (33) using porcine tooth bud cells, PLGA and PGA scaffolds produced a crossbreed tooth bone for the cure of tooth loss beside with alveolar bone resorption.…”