Coralline Calcium Carbonate Research Articles

Effects of Particle Size on Tensile Properties of Marine Coral Reinforced Polymer Composites

Use of marine coral as a bio-filler in polymer composites is a new trend in many engineering applications like structural, coating, chemical resistance and electrical applications. In the present work, composite materials were prepared using epoxy matrix/cuttle bone powder (coralline calcium carbonate) at three different particle size and five different weight ratio. X- ray diffraction (XRD), thermogravimetry (TGA) and Fourier transforms infrared spectroscopy (FT-IR) spectra were used to analyze the crystalline nature, thermal degradation and composition of the cuttlebone, respectively. Tensile strength of the composites was examined and the morphological characteristics were studied by scanning electron microscopy (SEM). Results revealed that smaller particle size filler reinforced composites had better mechanical strength and uniform distribution.

Porosities and pore sizes in coralline calcium carbonate

Coral is a material that recently has gained increased attention as a potential bone graft substitute material. The porosity and pore size distribution of the exoskeleton of eight different coral species were investigated by mercury intrusion and microscopy. A classification was established comprising two groups according to porosity: L-type, having low porosity (< 20 vol.%), and H-type, having high porosity (> 20 vol.%). According to literature, this value of 20 vol.% seems to be a lower porosity limit for successful surgical applications as bone graft substitution material. Pore size distributions are well-defined in three H-type species, each one having a different order of magnitude for the median pore diameter: Porites (order 2), Millepora (order 1), and Manicina (order 0). Tubular and slit pore geometries were suggested after microscopy.

Calcium-phosphate derived from mineralized algae for bone tissue engineering applications

In this work, several routes are described towards obtaining pure inorganic phases derived from Coralline officinallis red algae. The scanning electron microscopy studies have shown that it becomes possible not only to eliminate the undesired organic phase, but also to preserve or tailor the red algae typical microporosity. X-ray diffraction analysis was used to investigate the phase content of the red algae before and after performing the different treatment routes. Hydroxyapatite nanocrystallites were obtained after converting the coralline calcium carbonate skeleton by means of combining thermal and chemical routes. These results were confirmed by Fourier transform infra-red spectroscopic analysis. The processing routes herein described are very promising in order to design bioceramics of algae origin that might find useful applications as bone fillers and tissue engineering scaffolds.

A 5-year follow-up of 16 patients treated with coralline calcium carbonate (BIOCORAL) bone replacement grafts in infrabony defects.

A resorbable coralline calcium carbonate graft material (BIOCORAL) (CalCarb) was evaluated as a bone replacement graft in human periodontal osseous defects. Following initial preparation and re-evaluation, flap surgery was carried out. Bone defects were curetted and root surfaces subjected to mechanical debridement and conditioning with tetracycline paste. The bone defects were grafted with CalCarb, and the host flaps replaced or slightly coronally positioned. Weekly, then monthly deplaquing was performed until surgical reentry at 6-12 months. Patients were then followed on approximate 3 month recalls for > or =5 years. Significant clinical changes included improvement in mean vertical clinical probing attachment level from 5.7 mm at surgery to 4.2 mm at re-entry to 4.0 mm at 5 years, decrease in mean probing pocket depth from 6.1 mm at surgery to 3.0 mm at re-entry to 3.3 mm at 5 years, and mean gingival recession from +0.4 mm at surgery to 1.0 mm at re-entry to 0.7 mm at 5 years (all at least p<0.05 from surgery to re-entry and surgery to 5 years, N.S. from reentry to 5 years via ANOVA). These favorable long-term results with CalCarb suggest that CalCarb may have a beneficial effect in the long-term clinical management of infrabony defects.

Natural coralline calcium carbonate as an alternative substitute for skull defects

Natural coralline calcium carbonate as an alternative substitute for skull defects

Evaluation of bovine-derived bone protein with a natural coral carrier as a bone-graft substitute in a canine segmental defect model.

The efficacy of a bone-graft substitute (bovine-derived bone protein in a carrier of natural coral) in the healing of a segmental defect of a weight-bearing long bone was evaluated. Twenty dogs, divided into two groups, underwent bilateral radial osteotomies with creation of a 2.5 cm defect. On one side of each dog, the defect was filled with autogenous cancellous bone graft. Contralateral defects received, in a blinded randomized fashion, cylindrical implants consisting of natural coral (calcium carbonate) or calcium carbonate enhanced with a standard dose of bovine-derived bone protein (3.0 mg/implant; 0.68 mg bone protein/cm3). The limbs were stabilized with external fixators, and all animals underwent monthly radiographs. They were killed at 12 (group 1) or 24 (group 2) weeks, and regenerated bone was studied by biomechanical testing and histology. Radiographic union developed in all 20 radii with autogenous cancellous bone grafts and in all 10 of the radii with the composite implants. None of the radii with implants of calcium carbonate alone showed radiographic evidence of union. This represented a statistically significant difference between implant types. In addition, calcium carbonate implants both with and without bone protein demonstrated radiographic evidence of near total resorption of the radiodense carrier by 12 weeks. This resorption facilitated radiographic evaluation of healing. Mean values for biomechanical parameters of radii with the composite implants exceeded those for the contralateral controls at 12 and 24 weeks; the difference was statistically significant at 12 weeks. Histology revealed scant residual calcium carbonate carrier at either time in the defects with calcium carbonate implants; however, a moderate amount was present in defects with the composite implants. In these specimens, the residual carrier was completely surrounded by newly formed bone that may have insulated the calcium carbonate from further degradation. The present study used a carrier of granular calcium carbonate reconstituted with bovine type-I collagen to deliver an osteoinductive protein to the defect site. This carrier is of nonhuman origin (eliminating the risk of disease transmission or antigenicity) and resorbs rapidly. In this model, bovine-derived bone protein in a natural coral carrier performed consistently better than the gold standard autogenous cancellous bone graft in terms of the amount of bone formation and strength of the healed defect. This may have implications for removal of hardware or resumption of weight-bearing in certain clinical situations. These data also indicate that coralline calcium carbonate alone represents a poor option as a bone-graft substitute in this critical-sized segmental defect model.

Experimental Model of Posterolateral Spinal Arthrodesis in Sheep

The authors evaluated two bone substitutes in a posterolateral spinal arthrodesis (PSA) model in sheep: coral porites (99% calcium carbonate, Biocoral, Inoteb, France) and a biphasic ceramic (BCP) (65% hydroxyapatite and 35% B tricalcium phosphate, Triosite, Zimmer International). Bone substitutes would be of great interest for PSA. Previous trials began with two kinds of biomaterials: natural coralline calcium carbonate, and phosphate calcium ceramic. A lumbar PSA was performed in 11 sheep (coral group) and in 9 sheep (BCP group). Sacrifice and biomechanical tests were performed after 1 year. A large decrease of flexibility in all directions was obtained with both coral PSA and BCP PSA similarly to autologous graft. No nonfusion case was observed. In conditions close to the human surgery, a PSA can be obtained using either coral porites or BCP as bone substitutes.