Fabrication of fine apatite/collagen composite for osteoconductive apical barrier material

Abstract

Aiming at creating an apical barrier material that promotes recovery of defects in the root canal, a composite of apatite and collagen was developed. To achieve this, reconstitution and cross-link of atelocollagen, and calcification of reconstituted collagen fibers, were conducted under controlled stirring at 37°C. Deposits were identified as CO 3 -containing apatite and its crystallinity was comparable to that of bone apatite. After 20 hours of calcification, the composite contained apatite of about 60 wt. The composite and saline mixture had a pH of about 9. The mixture was easily set into a narrow space, such as the root canal, and was liquid permeable after being set into a root canal. The biological property of the composite was examined in vivo using the molar teeth of dogs. After 8 weeks, a thin layer of new bone-like tissue was formed along the inner wall of root canal. Without the composite paste, such a new bone-like tissue was not observed. Thus, the apatite/collagen composite showed potential as an apical barrier material with osteoconductivity.

Enzyme-mediated synthesis of ceramic materials

“…13) They also showed bioresorbability when implanted in the backs of Wistar rats, 11) and promoted the formation of bone-like tissue in the root canal of a dog. 14) These are good examples of applications which make full use of an advantage unique to enzyme-mediated ceramic synthesis: the use of alkaline phosphatase enables the precipitation of hydroxyapatite under ambient temperatures thereby avoiding unnecessary heat damage to reconstituted collagen.…”

Behaviour of calcium phosphate ester salts in a simulated body fluid modified with alkaline phosphatase: a new concept of ceramic biomaterials

“…SCPEs have been used as starting materials for calcium phosphate synthesis in artificial reaction systems. [11][12][13][14][15] For example, HAp was formed from calcium phenylphosphate (CaPP), which is a type of SCPE, in aqueous solutions containing ALP. We expect that similar transformation reactions occur in vivo environments.…”

Protein and peptide biotemplated metal and metal oxide nanoparticles and their patterning onto surfaces

“…Also, the culture of biomineralisation organisms in the laboratory can be challenging, and biomineral yields are often low. For example, Takenaka et al 44 promoted bone re-growth in canine tooth roots using implanted collagen fibrils pre-mineralised with calcium phosphate using the enzyme alkaline phosphatase. One success is the adaptation of magnetite formation in magnetic bacteria by the addition of cobalt.…”

“…43 In some cases, the whole protein sequence is not required, and shorter, less expensive synthetic peptide sequences based on the active sections of the protein can be used. For example, Takenaka et al 44 promoted bone re-growth in canine tooth roots using implanted collagen fibrils pre-mineralised with calcium phosphate using the enzyme alkaline phosphatase. Peptides have also been used to remineralise acid damaged areas on extracted teeth, and protect the teeth from further acid damage.…”