Loading deproteinized bovine bone with strontium enhances bone regeneration in rat calvarial critical size defects

Ole Zoffmann Andersen,Andreas Stavropoulos,Rosemary Adriana Chiérici Marcantonio,Maurício Andrés Tinajero Aroni,Guilherme José Pimentel Lopes de Oliveira,Luís Carlos Spolidório,Morten Foss

doi:10.1007/s00784-018-2588-6

Abstract

ObjectiveTo evaluate the effect of grafting with strontium (Sr)-loaded deproteinized bovine bone (DBB) on bone healing in calvarial critical size defects (CSD) in rats.Material and methodsTwo circular bone defects (5 mm in diameter) were created in the calvaria of 42 rats. One of the defects, randomly chosen, was grafted with (a) DBB, (b) DBB loaded with 19.6 μg/g of Sr (DBB/Sr1), or (c) DBB loaded with 98.1 μg/g of Sr (DBB/Sr2). The other defect was left empty as negative control. Groups of seven animals from each of the groups were euthanized 15 and 60 days post-op. Bone healing in the CSD was evaluated by micro-CT and histology/histomorphometry and immunohistochemistry.ResultsDBB/Sr2-grafted sites showed statistically significantly shorter radiographic residual defect length compared with DBB/Sr1- and DBB-grafted sites, and with empty controls at 60 days. Further, the amount of new bone formation in the DBB/Sr1- and DBB/Sr2-grafted sites was significantly higher compared with that in the DBB-grafted sites at 60 days. A larger number of DBB/Sr1- and DBB/Sr2-grafted sites presented with no- or only limited to mild inflammation, compared with the DBB-grafted sites, especially at 60 days. Higher expression of osteocalcin was observed in DBB/Sr1- and DBB/Sr2-grafted sites as compared to DBB-grafted sites.ConclusionGrafting with Sr-loaded DBB enhanced bone formation in CSD in rats, when compared with grafting with non-loaded DBB.Clinical relevanceGrafting with Sr-loaded DBB may enhance bone formation in bone defects.

Highlights

Limited bone availability due to disease, trauma, or congenital conditions often impairs proper implant placement
New bone formation at the edges of the defect had slightly progressed, but osteoblasts appeared reduced in numbers and more flattened (Fig. 3)
The results of the present study showed that grafting of Srloaded Deproteinized bovine bone (DBB) enhances bone formation in critical size defects (CSD) in rats, when compared with grafting of non-loaded DBB

Summary

Introduction

Limited bone availability due to disease, trauma, or congenital conditions often impairs proper implant placement. A variety of approaches has been employed for increasing the Technology, Aarhus University, Aarhus, Denmark 5 Department of Periodontology, Faculty of Odontology, Malmö. University, Carl Gustafs väg 34, SE-205 06 Malmö, Sweden available bone volume, primarily based on grafting of autogenous bone, bone substitutes, or growth factors, as mono-therapies or in combinations thereof. Autogenous bone is considered the Bgold standard,^ since it provides the scaffold, cells, and growth factors needed for bone formation. Autogenous bone grafting has limitations like donor site morbidity, unpredictable/large graft resorption, increased time and cost of treatment, and occasionally limited availability [1,2,3]; use of bone substitutes is, common. Deproteinized bovine bone (DBB) is among the most widely used bone substitutes in dentistry; DBB is osteoconductive, i.e., provides a scaffold for new bone formation and facilitates space provision. Successful outcomes after DBB use, on the long term, have been reported in numerous studies and for various indications, e.g., one- or two-stage maxillary sinus floor elevation procedures, lateral and vertical bone augmentation, and post-extraction alveolar ridge preservation [1, 2, 4, 5]

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Results

Conclusion