Dissolution of Human Teeth-Derived Hydroxyapatite

Abstract

We have been interested in human teeth which consist of hydroxyapatite (HA), but do not degrade for a long time. In order to overcome dissolution and mechanical degradation of man-made HA, biologically derived hydroxyapatite (BHA) ceramics were prepared from human teeth and their dissolving behavior was investigated in distilled water for 3-14 days and compared with an artificial HA made of synthetic HA powder. BHA ceramics were prepared by calcining freshly extracted human teeth at 900 degrees C and followed by sintering at 1200 degrees C for 2 h. All detectable peaks in the artificial HA are identical to HA lattice planes, whereas BHA consisted of a mixture of HA and beta-tricalcium phosphate (TCP). Although the artificial HA was expected to be stable in water, the surface dissolution initiated at grain boundaries followed by generated many separated grains and their associated pores. On the other hand, BHA showed that definite grains considered as beta-TCP were predominantly dissolved and the grains were separated from the matrix leaving pores. In the mean time, the rest region, mainly consisting of HA, did not show any evidence of dissolution. It indicates that BHA showed rather stable grain boundaries and lack of excessive dissolution in liquid environment.

Comparision of osteoconductivity of biologic and artificial synthetic hydroxyapatite in experimental mastoid obliteration

“…These results indicate that more extensive calcification of new bone occurred in the BHA group compared with the AHA group. Seo and Lee reported that BHA could be a good candidate in biomedical applications to improve the microstructural and mechanical stability of HA ceramics [17]. In the present study we were unable to determine whether the multinucleated cells were osteoclasts, and no sign of HA degradation was observed, since the particle phagocytosis through macrophages was likewise not observed.…”

“…In general, physical and chemical properties of HA materials are important factors affecting the dissolution process [13][14][15][16]. Seo and Lee investigated the comparison of dissolving behavior between BHA and AHA [17]. BHA showed rather stable grain boundaries and lack of excessive dissolution in a liquid environment.…”

Preparation and characterization of fluorinated porcine hydroxyapatite

“…It was previously reported that the amount of ionic substitution in human teeth-derived hydroxyapatite was below the detection limits for XRD and FTIR measurements 33) . Therefore, a bigger suite of characterization techniques was employed in this study as there was a concern that marginal ion substitution into HA might not be detectable.…”

Insight into Biological Apatite: Physiochemical Properties and Preparation Approaches

“…Biological hard tissues such as bones [11, 14, 16, 37, 57] and teeth [58] are the main raw materials in the preparation of biological apatite. For the commercial bone grafting products, most of the bone-derived substitutes are from bovine bone.…”