Pulp regeneration Do you think a tooth with a non-vital or inflamed pulp can become vital with a healthy one?! Yes, now this has become possible through a new process discovered, by researchers in biology, called " pulp regeneration or revascularization" Revascularization or regeneration is a biological alternative method to the conventional root canal treatment done using artificial material, gutta percha, in young immature teeth with necrotic or inflamed pulp. At first, let's know or remember what's the pulp, it's components and function?!. Pulp is a heterogeneous, loose connective tissue which consists of :- 1-Many types of cells, for example :- stem cells and immune cells. 2- Extracellular bundle of collagen fibres which give the pulp capacity to adapt pressure applied by stimuli during inflammatory reactions. 3- Vessels and nerves. It's function is to act as an alarm to different types of stimuli (chemical, thermal and mechanical), it also act as a source of nutrients to odontoblasts to produce healthy dentin which is a main component in tooth structure. The aim of revascularization is to compensate the function of the pulp lost by its inflammation or necrosis through forming new tissue inside root canal. This is done by induction of periapical stem cells to proliferate inside the canal to odontoblasts, by the organizing influence of hertwig epithelial root sheath, forming new dentin apically and laterally to enhance and complete root formation. Protocol of revascularization is as following:- - In the first session:- Make a proper access cavity, then irrigate with low concentrated sodium hypochlorite then saline then chlorhexidine. All of this should be done with proper isolation. Prepare the canal minimally, then disinfect it using a triple antibiotic paste (mix of 3 antibiotics : metronidazole, minocycline and cephalosporins) or calcium hydroxide paste as an intracanal medication below CEJ. Leave any of previous medications inside the root canal for 3 to 4 weeks until the second session. - In the second session :- Irrigate again properly to remove medications from the canal, then dry the canal properly. 2. Induce bleeding inside the canal by doing over instrumentation beyond apex. 3. Blood(rich in proliferated cells) should fill the canal until below CEJ, then wait for 15 minutes until blood clot formation. 4. Cover blood clot with MTA then put a wet cotton pallet over it then seal the cavity with glass ionomer. 5. Follow up every 6 months is a must to ensure complete root development. Treatment outcomes :- Tooth may response to revascularization properly by forming a good thickness of the root apically and laterally. Development of the root may be done perfectly laterally but not apically resulting in not completely formed apex. Development of the root may be done properly apically but not laterally resulting in thin root. Calcification of the root canal may occur. Formation of mineralized tissue between MTA and apex may occur. Conclusion, revascularization or regeneration is a biological process may survive a young permanent tooth and forming a strong tooth structure with restoring its vitality again.