An in vitro screening model to evaluate root conditioning protocols for periodontal regenerative procedures

Background: Preclinical studies have shown that the condition of the root s urface may play a decisive role for outcome of wound healing between a muco gingival flap and a denuded root surface. Root surface demineralization has been shown to promote the establishment of a new connective tissue attachm ent. Conversely, root conditioning with extracellular matrix proteins or fl uorides has produced outcomes characterized by a long junctional epithelium . Collectively, present evidence suggests that early events in the healing sequel; i.e., the adsorption and adhesion of blood elements to the root sur face are critical for outcomes of wound healing between a mucogingival flap and a denuded root surface. Ultimately understanding and control of these events are vital for successful design and execution of periodontal regener ative protocols, particularly those involving root conditioning. Consequent ly, the objective of this study was to develop a screening model for immedi ate evaluation of the influence of root conditioning protocols on the adsor ption and adhesion of blood to dentin surfaces. Methods: Planed and citric acid-treated human dentin surfaces were exposed to fresh blood allowed to clot and were then rinsed before scanning electro n microscopy evaluation. Results: Citric acid treated planed dentin surfaces presented a thick netwo rk of fibrin directly attaching to the dentin surface entrapping cellular e lements, mainly erythrocytes. In contrast, untreated, planed dentin exhibit ed an amorphous appearance with sparse strands of adsorbed fibrous proteins and few adherent erythrocytes. Conclusions: This in vitro screening model may effectively distinguish dent in surfaces with potential for enhanced adsorption and adhesion of blood el ements. Periodontal regenerative protocols involving root conditioning unsu ccessful in maintaining the experimentally imposed fibrin clot in this mode l may have lesser clinical significance than those that do.