The effect of changing apical foramen diameter on regenerative potential of mature teeth with necrotic pulp and apical periodontitis.

Objective: The aim of the present study was to evaluate the regenerative potential of permanent necrotic mature teeth with different apical foramen diameters in comparison to conventional endodontic treatment.

Methods: Pulp necrosis and periapical pathosis were induced in premolars (144 roots) in six mongrel dogs. The infected teeth were divided into six groups; conventional root canal treatment (RCT) group prepared up to apical preparation sizes #F3 ProTaper file, regenerative endodontic therapy (RET) groups; groups RET-F3, RET-F4, and RET-F5 where regenerative endodontic procedures were applied after apical preparation up to sizes #F3, F4, and F5 ProTaper file, respectively, control groups; and positive (P) and negative (N) groups included infected and healthy teeth respectively.