Bioactive Surface Structure and Bio-Absorption of Human Dentin Granules Designed by the Supersonic Demineralization and Biomimetic Coating Technique

Abstract

Demineralized dentin matrix (DDM) granules with excellent biocompatibility were designed using extracted human teeth by the cooling-pulverizing and supersonic demineralizing technique. Extracted teeth were pulverized together with saline ice at 12,000 rpm of a ZrO2 blade for 30 s in a ZrO2 vessel. The pulverized granules having 0.5-2.0 mm in granular size were dissolved by the supersonic treatment at 120 W and 38 kHz or 600 W and 28-100 kHz in 2.0 % HNO3 solutions to obtain partially or completely DDM granules. Dissolution efficiencies of the pulverized granules increased with increasing the supersonic time. At 600 W, dissolution efficiencies for DDM treated at 28 kHz were higher than those at other frequencies. The Ca/P molar ratios of the granules were 1.60-1.66, suggesting that partial DDM granules were composites of Ca 2+ -deficient hydroxyapatite (HAp) and collagen. At 120 W, as supersonic time increased, asperity on the surfaces of granules became outstanding due to elution of mineral components. At 45 min, DDM granules were completely demineralized and the weight decreased to about one-fifth. Hard asperity on surfaces and micro-crack were observed. Partially or completely DDM granules were implanted into the subcutaneous tissues of the back region of rats. At 4 weeks, completely DDM granules had a little smaller and more irregular shape than partially DDM ones. Infection and exclusion of DDM granules were not recognized, but inflammatory cell invasion was seen through bio-absorption of DDM due to the enzyme-digestion. To improve surface activity of DDM, DDM granules were soaked at 309.5 K and pH 7.40 in a simulated body fluid. At 48 h, HAp nano-crystals were almost homogeneously coated on the surfaces of completely DDM granules, while at 144 h, porous bone-like apatites were found. The HAp nano-crystals coating for DDM granules would form bioactive surface with specific pore structure and chemical nature.

Bio-Absorption of Human Dentin-Derived Biomaterial in Sheep Critical-Size Iliac Defects

“…Supersonic demineralization produced more nano- and micro-cracks, which increased the effective surface area. Thus, the body fluid will smoothly permeate through the micro-cracks in the PR-DDM [ 33 ]. These observations are scientifically important for hard tissue-derived graft material processing procedures.…”

“…Co., Ltd., Seoul, Korea) in 5 L of 0.34 N HNO 3 solutions at 100 W and 60 kHz for 30 min. The liquid temperature of the sample gradually increased with an increasing supersonic time up to 30 min, but they were maintained at less than 315 K to avoid denaturing proteins, as previously reported [ 33 ]. Finally, we used an extensive rinse with DW to prepare the PR-DDM.…”

Microcracks Design and Bone Induction of Skull Bone Modified by Ultrasonic Treatment Using Acidic Electrolyzed Water

“…It is recently shown that the surface area, tube diameter and length increase in dentin treated by ultrasonic irradiation with AEW in time dependent manner 14 . Result from our experiment was consistent to this finding.…”

Osteoinduction in Novel Micropores of Partially Dissolved and Precipitated Hydroxyapatite Block in Scalp of Young Rats

“…Interconnected macropore structure is necessary to promote body fluid permeation, neovascularization, and cell migration to the central pores, and micropores can provide more nucleation sites for bone-like apatite precipitation [ 22 , 23 ]. The supersonic acid-demineralization produces biologically simulant microcracks on the surface and inner bulk of commercial HAp products for precipitation of nano/micro crystals [ 19 , 24 ]. Additionally, all biomaterials, used for bone regeneration, should enhance bone growth directly in contact with the biomaterial surface from the surrounding bone, but it should also be capable of inducing osteoinduction [ 25 ].…”