Human tooth-related diseases often occur throughout life. The tooth is a complex organ, which includes different types of mineralized tissues. Although this complex structure provides it with hardness and durability, the tooth components are occasionally vulnerable to damage such as mechanical trauma, bacterial infections, and dental procedures as well as congenital defects. Once the tooth suffers loss, it is difficult to expect complete regeneration of the injured tissue, unlike other tissues such as hair and bone. However, the tooth components have some limited regenerative capacity except for the enamel regeneration. Tooth development proceeds through sequential and reciprocal interactions between the oral epithelium and the cranial neural crest-derived mesenchyme. Human dental tissues harbor stem/progenitor cells in the dental pulp, periodontal ligament, and dental follicle, which are responsible for tooth and associated tissue development or regeneration. Stem cell biology provides us with informative insights for the improvement of regenerative methods for tooth structures. Regenerative medicine using dental stem cells could become a feasible tool for novel approaches to treat dental diseases such as caries, endodontitis, periodontitis, and pathological defects of the maxillofacial bones and teeth. This chapter focuses on the different sources of dental stem cells that have been used for producing tooth components or a whole tooth. The improvement in tissue engineering approaches for dental tissue regeneration using dental stem cells is promising, and remains one of the greatest challenges in the dental field in the near future. © 2011 by Nova Science Publishers, Inc. All rights reserved.