This document discusses root surface biomodification agents that can be used to condition root surfaces and promote periodontal regeneration. It begins with an introduction to terminology and the limitations of mechanical root planing alone. It then covers the history of root surface conditioning dating back to the 1800s. The document categorizes and describes various root surface biomodification agents including citric acid, tetracycline, EDTA, fibronectin, enamel matrix proteins, platelet rich plasma, growth factors, and lasers. It provides details on the proposed mechanisms and applications of several commonly used agents.