EFFECTS OF ADDITION OF Α-Tricalcium PHOSPHATE POWDERS ON MATERIAL PROPERTIES OF THE CHELATE-SETTING HYDROXYAPATITE CEMENT

Abstract

We have previously developed a chelate-setting calcium-phosphate cement (CPC) consisting of hydroxyapatite (HAp) powders surface-modified with inositol hexaphosphate (IP6). In the present study, mechanically ball-milled α-tricalcium phosphate (α-TCP) powders were added into the IP6-HAp cement in order to enhance its anti-washout capability and mechanical properties. After optimization of the ball-milling conditions, the cement specimens mixed with various amounts of the prepared α-TCP powders were fabricated. Examinations of their mechanical properties revealed significant increase of compressive strength (CS) with the addition of the α-TCP powders. Further, it was demonstrated that the specimens of the IP6-HAp powders / the α-TCP powders mixing ratios of 20/80 and 30/70 [g/g] exhibited comparatively high anti-washout capability. In conclusion, these cements are promising chelate-setting CPCs with enhanced anti-washout capability and mechanical properties.

Cost-Effective Treatment of Hemihydrate Phosphogypsum and Phosphorous Slag as Cemented Paste Backfill Material for Underground Mine

“…ese substances, adhering to the surfaces of the HPG and PS particles, increased the water impermeability of the formed alkaline membrane on the surface of the particles and retarded the hydration of HPG and PS. In addition, partial Ca 3 (PO 4 ) 2 and CaF 2 gradually covered the surface of the particles and formed Ca 10 (PO 4 ) 6 (OH) 2 (hydroxyapatite), which further reduced the permeability of the semipermeable membrane [45]. erefore, the continuous release process of active substances in PS, HPG, and cement was suppressed.…”

Effects of Adding Polysaccharides and Citric Acid into Sodium Dihydrogen Phosphate Mixing Solution on the Material Properties of Gelatin-Hybridized Calcium-Phosphate Cement

“…Accordingly, we have recently succeeded in improving the compressive strength (CS) and anti-washout capability of the chelate-setting IP6-HAp cement by the addition of α-tricalcium phosphate (α-TCP) powder [ 5 ]. This improvement was attributed to interlocking between precipitated calcium-deficient hydroxyapatite (CDHA) crystals formed through hydrolysis of the α-TCP powder.…”

Bioresorbability of chelate-setting calcium-phosphate cement hybridized with gelatin particles using a porcine tibial defect model

“…Immediately prior to injection into the porcine tibial defects, the prepared gelatin particles were added into the premixed powder at a mixing ratio of 0/100 or 10/90 [g/g]. The powder was mixed for a further 1.5 min with the Chito-10 and Chondro-15 mixing solutions at the designated P/L ratios [g/cm 3 ] presented in Table 2. The obtained cement pastes (0.15 cm 3 ) were packed into plastic syringes for the injection.…”

“…At 5 min after mixing of the cement pastes, the pastes (0.3 cm 3 ) were extruded from syringes onto wire gauze, after which the cement pastes on the wire gauze were immersed in saline (30 cm 3 ). After 24 h of immersion at 37°C, the cement specimens on the wire gauze and the washed-out specimens that had seeped through the gauze were removed and dried at 60°C for 24 h. The washout ratios were calculated according to the following equation:…”

“…The premixed powder was mixed further with the prepared gelatin particles for an additional 5 min at a ratio of 100/0 Table 1 at the designated powder/liquid (P/L) ratios [g/cm 3 ], as presented in Table 2. The initial setting time (IST) was measured using a light Gillmore needle (113.4 g) in accordance with JIS T 0330-4.…”