• Journal of Biomedical Engineering Research
• /
• v.15 no.2
• /
• pp.195-200
• /
• 1994

To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that consists consisted of calcium phosphate and collagen according to the natural bone's main composition. The crystallinity of the synthesized apatite was shown to depend on the synthesis temperature. Carbonate apatite synthesized at $58{\circ}C$ demonstrated crystallinity very similar to that of the natural bone. By sintering the apatite over $700{\circ}C$ in vacuum, porous carbonate apatite could be obtained, and the pore extent was controllable according to the additive hydrogenperoxide volume.

• Journal of Korean society of Dental Hygiene
• /
• v.8 no.1
• /
• pp.13-22
• /
• 2008

This study compared tooth's remineralization using enamel surface artificially demineralized with 0.1M lactate and HCL solution using Vicker's Hardness Number(VHN) to compare CPP-ACP and remineralization of nano-sized Carbonate Apatite's initial caries. Using pH circulation models divided into 0% nano-CA, 5% nano-CA, 10% nano-CA, 10% CPP-ACP and D.W. they were treated for 5 minutes, three times a day for 14 days to get the following results. 1. There were no significant differences among the initial surface hardness of samples demineralized surface of front tooth in 5 groups. and all 5 groups' surface hardness reduced significantly after demineralization of enamel. 2. When inquiring into hardness changes through pH circulation model, the highest hardness change was in 5% nano-CA group. Also. 10% nano-CA and 10% CPP-ACP groups increased significantly. but there was no significant difference statistically. In generalizing the above experiment results, nano-sized Carbonate Apatite showed remineralization, and compared to 10% CPP-ACP group, 5% nano-CA had remineralization to artificial caries. thus implies that when we develop method to contact with tooth of nano-CA in the future, it is expected to gain synergy effect on function of saliva, a natural remineralization material.

• Biomaterials Research
• /
• v.22 no.4
• /
• pp.346-351
• /
• 2018

Background: Carbonate apatite ($CO_3Ap$) and silica-calcium phosphate composite (SCPC) are bone substitutes with good prospect for dental application. SCPC creates a hydroxyapatite surface layer and stimulate bone cell function while, $CO_3Ap$ induce apatite crystal formation with good adaptation providing good seal between cement and the bone. Together, these materials will add favorable properties as a pulp capping material to stimulate mineral barrier and maintain pulp vitality. The aim of this study is to investigate modification of $CO_3Ap$ cement combined with SCPC, later term as $CO_3Ap-SCPC$ cement (CAS) in means of its chemical (Calcium release) and physical properties (setting time, DTS and pH value). Methods: The study consist of three groups; group 1 (100% calcium hydroxide, group 2 $CO_3Ap$ (60% DCPA: 40% vaterite, and group 3 CAS (60% DCPA: 20% vaterite: 20% SCPC. Distilled water was employed as a solution for group 1, and $0.2mol/L\;Na_3PO_4$ used for group 2 and group 3. Samples were evaluated with respect to important properties for pulp capping application such as pH, setting time, mechanical strength and calcium release evaluation. Results: The fastest setting time was in $CO_3Ap$ cement group without SCPC, while the addition of 20% SCPC slightly increase the pH value but did not improved the cement mechanical strength, however, the mechanical strength of both $CO_3Ap$ groups were significantly higher than calcium hydroxide. All three groups released calcium ions and had alkaline pH. Highest pH level, as well as calcium released level, was in the control group. Conclusion: The CAS cement had good mechanical and acceptable chemical properties for pulp capping application compared to calcium hydroxide as a gold standard. However, improvements and in vivo studies are to be carried out with the further development of this material.

• Journal of Veterinary Clinics
• /
• v.29 no.4
• /
• pp.352-355
• /
• 2012

Hypospadias is a rare congenital malformation of the urethra reported in cattle. The urethral lumen of male indigenous Korean calf is open along the ventral aspect of the penis in the perineal region. Renal abscess and renal stone formation causing urinary tact infection has not been reported in hypospadia calves. The objective of this study was investigation for renal abscess and renal stone formation through autopsy. Histopathological examination and laboratory tests were performed. At autopsy, the pustules were formed on the right renal cortex, and the renal medulla abscess were formed on right and left part of the renal pelvis. Histopathological finding, this case was diagnosed as severe acute suppurative and necrotizing pyelonephritis, and severe chronic interstitial nephritis with fibrosis and moderate multifocal acute cystitis with edema. Milky exudate of the kidney has been identified as Actinomyces meyeri using the VITEK-2 system for identification of bacteria, and the stone has been identified as carbonate apatite using FT-IR system for quantification analysis. This case report describe the hypospadias complicated with urinary tract infection due to carbonate apatite stones and Actinomyces meyeri.

• Journal of Biomedical Engineering Research
• /
• v.10 no.2
• /
• pp.89-90
• /
• 1989

To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased.

• Journal of Veterinary Clinics
• /
• v.30 no.6
• /
• pp.503-505
• /
• 2013

A cross breed dog (6-year-old, 6 kg, intact male) was referred with hematuria. The dog had been treated for years owing to the urinary bladder calculi. On abdominal radiography, prostatic calculus was demonstrated in the prostatic area. In addition, ultrasonography and computed tomography (CT) scan would confirm that the part of calculus protruded within the prostatic urethra. The patient underwent a prostatolithotomy and traumatic prostatic urethra was carefully sutured and the omentum was filled with the prostate lumen. A crystallographic analysis of the stone showed 80% magnesium ammonium phosphate (struvite) and 20% carbonate apatite. The leakage of the urine was not observed post-operation and the hematuria improved and there was no specific problem at the 6 months follow-up.

• Korean Journal of Soil Science and Fertilizer
• /
• v.27 no.4
• /
• pp.247-254
• /
• 1994

This study was conducted to characterize the chemical and mineralogical properties of representative phosphate rocks from North Carolina and Florida, and to find out the method for increasing the citric acid (two percent) solublility of phosphate rock. The the results are summerized as follows : 1. Major composition of phosphate rock was carbonate apatite containing small amounts of calcite and quartz. The differential thermal analysis(DTA) did not show endothermic or exothermic peak till $1,000^{\circ}C$. 2. Two percent citric acid solublility of phosphate rock was increased with the finess of particle size, but the water solublility was not affected by the particle size. Long time calcinated under high temperature had negative effect, while the incubation with 2% citric acid under low temperature had positive effect on solubility. 3. To increase the solubility of phosphate rock it was mixed with farmyard and barnyard manure and acidulated. Citrate solubility by treatment with sulfuric acid was more effective than nitric acid. Acidulation with thirty percent sulfuric acid increased both citric acid solubility and water solublility. Treatment with glutamic acid had little effect on the solubility of phosphate rock.

• Journal of Biomedical Engineering Research
• /
• v.16 no.1
• /
• pp.57-60
• /
• 1995

To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased.

• The Journal of the Petrological Society of Korea
• /
• v.11 no.2
• /
• pp.90-102
• /
• 2002

The studied Fe-REE ore consists of magnetite, ankerite, siderite, magnesite and strontianite as the major constituent, and monazite, columbite, fergusonite, apatite, aegirine-augite, Na-amphibole, pyrite, chalcopyrite, sphalerite, molybdenite and barite as accessaries. Wall rock of ore deposits is replaced to fenite due to Na-metasomatism and mainly consists of sugary albite and Na-amphibole. Monazite $Ce_{0.49}La_{0.31}Pr_{0.14}Nd_{0.03}Gd_{0.03})PO_4$ is the main mineral for REE deposit and shows myrmekitic intergrowth with strontianite $Ca_{0.02-0.16}Sr_{0.84-0.98}CO_3$ and is corroded by carbonate minerals. Mineral forming sequence can be divided into early and late periods by the development of microfractures. The early period minerals such as magnetite, ankerite, magnesite, monazite and apatite show well developed networks of microfractures due to cataclastic deformation caused by enriched $CO_2$ gas in melts during emplacement. The late minerals of columbite, fergusonite, siderite molybdenite, chalcopyrite and sphalerite formed after the brecciation event and have little micro-fractures. Ankerite, magnesite, monazite, strontianite, barite and pyrite seem to be formed continuously from the ealy to the late period since they show textures both with well developed fractures and also with little fractures. Mineral chemistry, mineral assemblages such as various carbonate minerals, magnetite, REE minerals of monazite and fergusonite, Sr mineral of strontianite, and Nb minerals of columbite, myrmekitic texture of monazite and ankerite, and well developed fenite along ore deposits observed from this studied area strongly indicate that this Hongcheon Fe-REE ore deposits are formed from carbonatitic melt and its rock type is late differentiated Fe-carbonatite or ankerite-carbonatite.

• Journal of Periodontal and Implant Science
• /
• v.49 no.6
• /
• pp.382-396
• /
• 2019

Purpose: The purpose of this study was to elucidate the efficacy and safety of carbonate apatite (CO₃Ap) granules in 2-stage sinus floor augmentation through the radiographic and histomorphometric assessment of bone biopsy specimens. Methods: Two-stage sinus floor augmentation was performed on 13 patients with a total of 17 implants. Radiographic assessment using panoramic radiographs was performed immediately after augmentation and was also performed 2 additional times, at 7±2 months and 18±2 months post-augmentation, respectively. Bone biopsy specimens taken from planned implant placement sites underwent micro-computed tomography, after which histological sections were prepared. Results: Postoperative healing of the sinus floor augmentation was uneventful in all cases. The mean preoperative residual bone height was 3.5±1.3 mm, and this was increased to 13.3±1.7 mm by augmentation with the CO₃Ap granules. The mean height of the augmented site had decreased to 10.7±1.9 mm by 7±2 months after augmentation; however, implants with lengths in the range of 6.5 to 11.5 mm could still be placed. The mean height of the augmented site had decreased to 9.6±1.4 mm by 18±2 months post-augmentation. No implant failure or complications were observed. Few inflammatory cells or foreign body giant cells were observed in the bone biopsy specimens. Although there were individual differences in the amount of new bone detected, new bone was observed to be in direct contact with the CO₃Ap granules in all cases, without an intermediate layer of fibrous tissue. The amounts of bone and residual CO₃Ap were 33.8%±15.1% and 15.3%±11.9%, respectively. Conclusions: In this first demonstration, low-crystalline CO₃Ap granules showed excellent biocompatibility, and bone biopsy showed them to be replaced with bone in humans. CO₃Ap granules are a useful and safe bone substitute for two-stage sinus floor augmentation.