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

Abstract

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.