Effects of Calcitonin, Calcitonin Gene-Related Peptide, Human Recombinant Bone Morphogenetic Protein-2, and Parathyroid Hormone-Related Protein on Endodontically Treated Ferret Canines

Introduction: The purpose of this study was to determine whether human recombinant bone morphogenetic protein-2 (rhBMP-2), calcitonin gene-related peptide (CGRP), calcitonin (CT), or parathyroid hormone-related protein (PTHrP) promoted reparative tertiary dentin or osteodentin formation in ferret canines. Methods: Ferrets had up to 4 pulpotomies performed under anesthesia. All pulps had sterile absorbable sponge of a standard size placed in contact with the pulp. The sponge contained sterile saline, rhBMP-2, CGRP, CT, or PTHrP. The opening was filled with an intermediate restorative material. After 6 weeks, the ferrets were anesthetized, and the pulpotomized teeth were extracted. The canines were fixed, decalcified, sectioned, and stained with hematoxylin-eosin. Sections were selected from the area of the opening, and the amount of reparative tertiary dentin and osteodentin was measured by using a digitizer. Results: Analysis of the photomicrographs showed that rhBMP-2 induced 0.58 +/- 0.19 mm(2) osteodentin and 0.56 +/- 0.18 mm(2) tertiary dentin. CGRP induced 0.46 +/- 0.05 mm(2) osteodentin and 0.38 +/- 0.04 mm(2) tertiary dentin. The amount of rhBMP-2-induced and CGRP-induced osteodentin and tertiary dentin was significantly (P < .001) more than that found in the sterile saline-treated teeth (0.29 +/- 0.03 mm(2) osteodentin and 0.14 +/- 0.03 mm(2) tertiary dentin) or CT (0.2 +/- 0.06 mm(2) osteodentin and 0.16 +/- 0.05 mm(2) tertiary dentin; P < .01). PTHrP significantly (P < .05) reduced the amount of osteodentin (0.17 +/- 0.02 mm(2)) observed in the saline-treated teeth but was not significantly different in the amount of tertiary dentin observed. Conclusions: RhBMP-2 and CGRP promoted more pulpal healing than either CT or PTHrP. (J Endod 2009;35:866-869)