Pre-Treat Xenogenic Collagenous Blocks of Bone Substitutes with Saline Facilitate Their Manipulation and Guarantee High Bone Regeneration Rates, Qualitatively and Quantitatively

Abstract

Deproteinized bovine bone mineral particles embedded in collagen (DBBM-C) are widely used for bone regenerations with excellent, albeit sometimes variable clinical outcomes. Clinicians usually prepare DBBM-C by mixing with blood. Replacing blood by saline represents an alternative. We investigated if saline treatment could improve DBBM-C i. handling in vitro and ii. biological performances in a rabbit calvarial model. In vitro, DBBM-C blocks soaked in saline or blood were submitted to compression tests. In vivo, four poly ether ether ketone (PEEK)cylinders were placed on 16 rabbit skulls, filled with DBBM-C soaked in blood or saline for 2–4–8–12 weeks before histomorphometry. DBBM-C blocks were fully hydrated after 30 s in saline when 120 s in blood could not hydrate blocks core. Stiffness gradually decreased 2.5-fold after blood soaking whereas a six-fold decrease was measured after 30 s in saline. In vivo, saline treatment allowed 50% more bone regeneration during the first month when compared to blood soaking. This difference was then no longer visible. New bone morphology and maturity were equivalent in both conditions. DBBM-C saline-soaking facilitated its handling and accelerated bone regeneration of highly qualitative tissues when compared to blood treatment. Saline pretreatment thus may increase the clinical predictability of bone augmentation procedures.

Identification of Type-H-like Blood Vessels in a Dynamic and Controlled Model of Osteogenesis in Rabbit Calvarium

“…In these controls, no bone synthesis was observed apart from the healing of intramedullary perforations created to attract osteogenic precursors and vascularization. This is in line with previous studies that also relied on such an ectopic augmentation model [22,23,25,26]. The scaffold employed consisted of 0.25-1 mm bovine bone particles that have represented a gold standard in orofacial bone regeneration for several decades.…”

“…In the bone regeneration model employed herein, several identical cylinders are screwed onto the skull of an animal and filled with a scaffold [22,23]. The scaffold is necessary for bone growth, as it triggers a vertical "ectopic" osteogenesis that extends above the native calvarial bone plateau.…”

“…Additionally, the choice of the animal model is also important. We relied on rabbit skulls, a model that allows the simultaneous assessment of four cylinders [22,23,28], and thus the testing of four simultaneous conditions on the same animal. Such optimization of the workflow constitutes an important ethical argument.…”

“…Surgical procedures were performed as previously described by our group [22,23]. Briefly, animals were left for one-week acclimation in the facility and received a prophylactic broad-spectrum antibiotic coverage (2 h preoperative, 3 days postoperative, enrofloxacin Baytril 10%, 5-10 mg/kg PO, Bayer, Leverkusen, Germany).…”

“…Masson-Goldner staining, which specifically labels collagen fibers green/blue, was employed to further discriminate cells from the surrounding connective tissue and for the semi-quantitation of newly formed bone. Observation was performed on a stereo video microscope (VHX-5000, Keyence, Itasca, IL, USA) following a procedure previously described by our group [22].…”