While OCP exhibits good properties in terms of bone growth, very stringent synthesis requirements make it difficult for mass productions, but nevertheless has shown promise not only in-vitro, but also in in-vivo clinical case studies.

[3] Calcium phosphate has been used to treat various illnesses such as rickets, scrofula, diarrhea, ulcerations, and inflammation, but its applications in orthopedics and dentistry has been the main area of focus for many years.

[5][6] Along with this, compared to other forms of calcium phosphate OCP has been found to have greater levels of biocompatibility and increased rates of osteointegration.

[5] The advantageous properties of OCP have made it a primary candidate for many orthopedic uses, and although mass production has been utilized, extremely strict chemical constraints make it difficult to mass-produce and fast paces.

[17] In order to create OCP, ɑ-TCP along with calcium carbonate and brushite (CaHPO4·2H2O) are formed into a solid state in preparation for the hydrolysis.

[18] So, upon finishing the precipitation reaction the solution is mixed gently for times varying from 3 to 12 hours which results in well defined octacalcium phosphate crystals which can then be extracted via filtration using membrane fillers.

[13] In-vivo pre-clinical Studies comparing Gel-OCP composites to pure gel control groups have found that the gel scaffold is capable of regenerating substantial amounts of bone within months (~4 months) of implantation, indicating that the gel-OCP composites exhibit high osteoconductivity allowing for enhanced bone regeneration.

[13] Along with this, collagen based composites exhibit similar properties and structure to natural bone tissue such as high osteoconductivity, and enhanced biointegration.

[13][21][11] Alginate is a polysaccharide derived from a form of brown seaweed that has spiked interest due to its favorable biocompatibility and its ease of gelation.

[13] Hyaluronic acid is a naturally occurring polymer that is present in skin, tendons, and synovial fluid as a component of the connective tissue's extracellular matrix.

[13] Synthesis of Hyaluronic-OCP scaffolds is achieved by simply mixing OCP granules with hyaluronic acid at a controlled pH level and results in an injectable paste.

[13] In terms of bone regeneration hyaluronic acid-OCP composite pastes have shown enhanced osteoconductivity soon after injection, and exhibited biodegradation by osteoclasts.

[12] A higher osteoconductivity was first observed in the bone tissue response in mouse where OCP was placed onto the calvaria in its granule form, showing it to have higher osteoconductivity than other Ca-P materials like anhydrous dicalcium phosphate (DCP), amorphous calcium phosphate (ACP), calcium deficient HA (CDHA), and stoichiometric HA.

[12] During thermodynamic conversion of OCP to HA it was found to strongly stimulate cell capacity via hydrolysis in in-vivo environments.

[24] The functionalization of therapeutic agents for drug-delivery systems for the treatment of bone pathologies has focused mainly on Ca-P nanoparticles, HA nanocrystals, and apathetic cements, coatings and porous scaffolds, but literature on the use of OCP in these applications is limited.

[13] Alendronate, a commonly used BP, has been combined with OCP in some studies, demonstrating inhibited osteoclastogenesis and osteoclast differentiations but enhanced osteoblast proliferation and activity.

[13] In-vitro tests carried out on osteoblast, osteoclast, and endothelial cell biomimetic environments showed that BPs imbue functionalized OCP with antresorptive and antitumor properties.

One study conducted a safety assessment after OCP collagen composites were implanted in cases of alveolar bone defects, indicating that all participants completed the trial without major problems in condition.

[25] No serious liver, renal dysfunction, electrolyte imbalance, or abnormal urinalysis results were shown, and a healthy immune response was noted.

All participants consisted of patients undergoing either sinus floor elevation, socket preservation, cystectomy of the jaw, or bone grafting at the alveolar cleft in preparation for a dental implant.

Histological analysis of sinus floor elevation for a patient within the two stage group showed newly formed bone at the site of OCP/Col implantation and no scar or inflammation cells were found.

Table #1: Average vertical Bone Widths Before & 24 weeks Post OCP/Co Treatment Case study #2 involved three male patients, ages 63 to 77, who had previously undergone sinus or alveolar ridge augmentation with at least one year of functional loading.

Four months after the first implantation surgery a modified periosteal fenestration was performed due to the loss of attached mucosa bucally.