Micro-computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

Abstract

High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine’s jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custom-built micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor in-vivo bone regeneration studies for greater regenerative process understanding.

Nanocalcium sulfate and collagen biomaterials: Effects on osteoblastic cells

“…The alkaline phosphatase activity studies support the concept that collagen together with CS increases the differentiation of osteoblastic Most recently, a novel nanocalcium sulfate (nCS) material fabricated in our laboratory has been shown to have enhanced physical properties, due to its nanosized particles, for osteoconduction and subsequent bone regeneration [11]. The previous studies with this material have shown that nCS particles have a much higher surface area and superior mechanical strength than the traditional calcium sulfate.…”

“…Most recently, the nanosized calcium sulfate product, nCS, used in this present study was shown to be an effective material to support in vivo bone regeneration in a canine model of critical mandibular defects [11]. The rationale for coating collagen membranes with nCS is based on characterization of this material as one with higher surface area and superior mechanical strength than the traditional calcium sulfate [12].…”

“…nCS was fabricated from conventional size calcium sulfate according to the cryo-vacuum technique previously developed in our laboratory and patented by U.S Patent 7767226 [12]. The physicalchemical characteristics of this nano-sized material as well as its biocompatibility and osteoconductive properties have been previously reported and described in detail [11,12]. Collagen discs (approx.…”

Hard and soft tissue integration of immediate and delayed implants with a modified coronal macrodesign: Histological, micro‐CT and volumetric soft tissue changes from a pre‐clinical in vivo study

“…The evaluation of bone volume changes with micro‐CT has been recently reported, concluding that this method allowed for reliable evaluation of crestal bone changes around dental implants (Beck‐Broichsitter et al., ; De Barros, Novaes, De Carvalho, & De Almeida, ; Khobragade et al., ). Moreover, this technology permits the evaluation of the bone around the whole circumference of the implant (Becker, Klitzsch, Stauber, & Schwarz, ).…”

Application of fractal dimension for quantifying noise texture in computed tomography images

“…The purpose of this study was to investigate fractal dimension as a scalar metric of noise texture. Previous studies applied fractal dimension as a feature for tissue classification tasks such as carcinoma detection and bone growth assessment . A previous study demonstrated the challenges of estimating the fractal dimension of a texture from a discrete image .…”