From the moment an egg is fertilized and a single cell zygote formed, it begins to divide and redivide, simultaneously differentiating into specialized cells that give rise to different body parts. A certain population of these cells which exhibit similar but limited potential to differentiate continue to exist in various tissues of the body throughout the lifetime of an organism. The science of tissue engineering exploits this valuable ability of stem cells/progenitor cells to regenerate or repair new tissues. In conservative dentistry, regenerative endodontic procedures aim to regenerate the pulp dentin complex utilizing dental stem cells, growth factors and scaffold matrix. Ability to isolate and harvest stem cells, improvements in the design of scaffold materials, advances in cell culture technology and commercial availability of growth factors has facilitated regeneration of pulp and dentin. Clinical techniques whereby these tissues can be regenerated include the surgical implantation of laboratory grown synthetic pulp and dentin tissues; implanting a mix of scaffold and growth factors and promoting endogenous recruitment of stem cells; or enhancing revascularization into root canals by encouraging stem cells to grow into natural fibrin clots. In this article, the components and techniques for pulp dentin regeneration will be discussed. Several preclinical studies have reported positive results but clinical cases reported in the literature are still very few. Additional research involving multiple disciplines that will translate these preclinical research outcomes into successful clinical applications need to be conducted. Every year a huge population of dental patients suffer from diseases like dental caries, which left untreated can progress to cause extensive loss of enamel and dentin with concomitant pulpal involvement. Currently, the treatment options available for a carious tooth are restoration of the defect with a filling material when the lesion size is small to moderate. In deep lesions extending close to a vital pulp, capping the pulp with a material which promotes pulpal healing and reparative dentin formation is the treatment of choice. In cases where the pulp is involved beyond repair, the dentist is left with no other option but to perform a root canal treatment which includes removing whole of the dental pulp and replacing it with an artificial filling material. Efforts have continuously focused to overcome limitations associated with existing restorative materials and evolve a material that mimics natural tooth structure as closely as possible. Clinical outcomes are also not always predictable especially in teeth with incompletely formed roots, resorption defects, fractures and extensive caries. Moreover, endodontic treatment leaves a tooth brittle and more prone to caries because the tooth is devoid of its blood supply, innervation and ability to produce secondary dentin. Developing a treatment therapy that will eliminate the use of any artificial material and enable replacement of lost tissues with natural pulp and dentin is an attractive option. Applying tissue engineering concepts can help turn this dream into reality. A combination of stem cells, scaffold and growth factors maintained in a controlled and regulated environment has shown immense potential to repair and generate tissues of the endodontium. doi : 10.5214/ans.0972.7531.2010.170109 Co mpeting interests: None. Source of Funding: None Received Date: 16 Dec 2009 Revised Date: 13 Jan 2010 Accepted Date: 28 Jan 2010