Such treatment enlarges dentinal tubules into which healing connective tissue can enter. So, its use can prolong the survival of the teeth by enhancing periodontal regeneration in addition to its beneficial effect as an adjunctive therapy to mechanical debridement in the treatment of periodontal disease. Through this book, the author wants to draw the attention of both dental clinicians as well as patients towards the therapeutic potential of Doxycycline HCl in root biomodification. Root biomodification is a treatment procedure employed for periodontal regeneration that uses acid substances or chelating agents to remove the smear layer and expose root collagen fibers. Doxycycline is believed to enhance maturation and differentiation of osteoblasts. Various agents have been employed in the past to achieve suitable results.