• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.739-750
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• 1997

Treatment of root perforation elicits special considerations due to its blood-contaminated circumstances. It is known that conventional dental restorative materials are all leaking. Calcium sulfate is the material which react with water to become chemically set. This study, therefore, was performed to develop a new compound containing calcium sulfate and to evaluate its physical and biological characteristics. Three materials were used, IRM, calcium sulfate, calcium sulfate-hydroxyapatite compound. The composition of the calcium sulfate-hydroxyapatite compound was basically 50 % of calcium sulfate and 50 % of hydroxyapatite mixed with guajacol. The materials were mixed in conventional way and underwent four physical test procedures, setting time, solubility test, compressive strength, and marginal leakage test. All materials were evaluated under the scanning electron microscope to examine the marginal sealing ability. Animal experiment was also performed to test the materials' tissue response. Twenty-four dog's premolars were tested with either furcation perforations or apical retro-fillings. From the results, we found that calcium sulfate possess the good marginal sealing ability. However, calcium sulfate creates many voids which is caused by crystal thrusting action when it reacts with water. It seemed that the voids caused disintegration of the material which eventually lead to tissue reaction. By compounding calcium sulfate and hydroxyapatite, we were able to obtain the better physical properties but it showed larger marginal gap between the material and the root surface. Within the six weeks observation period, both IRM and calcium sulfate-hydroxyapatite compound showed good tissue responses in animal experiment. It is concluded that calcium sulfate would be the material of choice in root perforation repair, but the physical property needs to be further improved.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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• pp.217-227
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• 1998

Calcium sulfate(plaster of Paris) has been used in dental and orthopedic surgery for about 100 years. It is well known that the plaster is bioresorbable, biocompatible, defect conformable and moldable. The purpose of this study is to evaluate two effects of calcium sulfate on bone regeneration, that is, the effects of graft materials and barrier for bone regeneration. Cortical bone defects were formed for recipient site on the femurs of 19 Sprague-Dawley rats. The autogenous particulated bone and calcium sulfate were grafted to the defects. Calcium sulfate paste, $Gore-Tex^R$ membrane(W.L. GORE & ASSOCIATES LTD., U.S.A.) and rubber sheet were used for the shielding materials. The results were as follows : 1. Calcium sulfate that had been grafted in the cortical bone defect was almost resorbed before bone remodeling, resultantly had little effect on bone regeneration. 2. Resoption process of calcium sulfate grafted on the bone grafting area tends to be accelerated, as being divided into numerous small particles progressively. Under the situation where the calcium sulfate was protected, with the coverage of fascia, $Gore-Tex^R$ membrane or rubber sheet, new bone formation was confirmed with presence of calcium sulfate particles over 6 weeks after grafting. 3. In the case of calcium sulfate covered with membrane, distinct bone formation was observed on the marrow space of femur adjacent to the plaster mass. 4. Rubber shielded plaster group revealed new bone trabeculae under the rubber sheet, but it showed ischemic degeneration of superficial cortical bone.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.785-804
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• 1997

It was well known that calcium sulfate was biocompatible, resorbed rapidly in the body, had potential as a good barrier membrane. Platelet-derived growth factor(PDGF) was one of polypeptide growth factor that had been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purpose of this study was to evaluate the effects of a combination of calcium sulfate and PDGF on periodontal ligament cells in vitro to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the premolar tooth extracted for the orthodontic treatment. Cells were cultured in ${\alpha}-MEM$ contained with 20% FBS, at the $37^{\circ}C$, 100% of humidity, 5% $Co_2$ incubator. Cells were inoculated and cultured into 96 well culture plate with $1{\times}10^4cells/well$ of ${\alpha}-MEM$ for 1 day. After discarding the medium, those cells were cultured in ${\alpha}-MEM$ contained with 10% FBS alone(control group), in calcium sulfate(calcium sulfate group), in calcium sulfate treated with 15ng/ml of PDGF-BB(calcium sulfate+PDGF group), in ${\alpha}-MEM$ contained with 10% FBS treated with 15ng/ml of PDGF-BB(PDGF group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTT assay, collagen synthesis. The results were as follows. 1. In the analysis of cell proliferation by cell counting, both calcium sulfate group and calcium sulfate plus PDGF group showed no stastically significant difference compared to control group, but there was stastically significant difference between PDGF group and calcium sulfate group at 1, 2 day(P<0.05). 2. In the analysis of cell proliferation by MTT assay in calcium sulfate extracts, both calcium sulfate group and calcium sulfate plus PDGF group showed no stastically significant difference compared to control group, but there was stastically significant difference between PDGF group and calcium sulfate group at 2, 3 day, and between calcium sulfate plus PDGF group and calcium sulfate group at 2 day(P

• 대한골관절종양학회지
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• 제9권1호
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• pp.31-37
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• 2003

목적: 양성 골종양 제거후 발생한 골결손을 골 대체물의 하나인 calcium sulfate를 이용하여 치료하고 그 결과를 보고하고자 한다. 대상 및 방법: 2000년 12월부터 2001년 11월까지 18명, 18례의 양성 골종양 환자에 대하여 calcuim sulfate(Osteoset$^{(R)}$:Wright Medical Co. USA)를 골 대체물로 이용하여 치료하였다. 남자 11명, 여자 7명이었으며 평균 연령은 28.4세였다. 모든 예에 대해 골결손 부위를 steoset$^{(R)}$을 이용하여 치료하였고, 자가골과 함께 사용한 경우가 6례, 동종골과 함께 사용한 경우가 2례, Osteoset$^{(R)}$ 단독으로 사용한 경우가 10례이었다. 추시기간은 최단 8개월에서 최장 19개월로 평균 12.3개월이었다. 주기적인 추시에서 관찰된 단순 방사선 사진에서 Osteoset$^{(R)}$의 흡수 정도와 골 생성 정도를 술 후 사진과 비교하여 백분율로 표시하여 관찰하였다. 결과: 술 후 3개월에 92 %의 흡수율을 관찰할 수 있었고, 술 후 6개월에는 89%의 골 생성을 관찰할 수 있었다. Osteoset 단독으로 사용한 경우나 자가골 또는 이종골을 같이 사용한 경우에서 흡수율이나 골 생성에 유의한 차이는 없었으며, 술 전 진단이나 병변 부위에 따른 차이도 발견할 수 없었다. 최종 추시시 특이한 합병증은 없었다. 결론: Calcium sulfate는 생체 적합성이 뛰어나고, 큰 골결손 부위에도 사용할 수 있으며 쉽게 사용 가능하고 골전도 작용이 있는 등의 장점을 가지고 있다. 따라서 양성 종양의 제거시 발생한 골결손의 치료제로, 특히 자가골 이식이 어려운 소아에서 유용하게 사용할 수 있을 것으로 사료된다.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.235-247
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• 1998

Calcium sulfate has a long history of medical use as an implant material. The biocompatibiliry of the material has been clearly established. Bone ingrowth concomitant with resorption occurs rapidly with efficient conduction of bone from particle to particle. Calcium sulfate also has a potential for functioning as a good bamer membrane. The purpose of this study was to compare the biocompatibility of different types of calcium sulfate grafting materials including an expelimental calcium sulfate compound on periodontal ligament cells in vitro as a preliminary test towards the development of a more convenient and useful form of grafting material which could promote regeneration of periodontal tissue. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. cells were cultured in a.MEM culture medium containing 20% FBS, at $37^{\circ}C$ and 100% humidity, in a 5% CO2 incubator. Cells were cultured into 96 well culture plate $1{\times}104$ cells per well with $\alpha$-MEM and incubated for 24 hours. After discarding the medium, those cells were cultured in $\alpha$-MEM contained with 10% FBS alone (control group), in medcal-grade calcium sulfate(MGCS group), in plaster(plaster group), experimental calcium sulfate paste(CS paste group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTI assay, collagen synthesis. The results \vere as follows. 1. In the analysis of cell proliferation by cell counting, both medical-grdde calcium sulfate group and plaster group showed no stastically significant difference at day 1, 2, 3 accept for plaster group at day 1 compared to control group, but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.05). 2. In the analysis of cytotoxicity by MIT assay, both medical-grade calcium sJlfate group and plaster group showed no stastically significant difference compared to control group at day 1, 2, 3 but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.OS). 3. In the analysis of collagen synthesis by immunoblotting assay, high level was detected for medical-grade calcium sulfate group and plaster group at day 1, 2, 3 compared to CS paste group. On the basis of these results, medical-grade calcium sulfate and plaster was shown to possess biocompatibility whereas the CS paste had unfavourable outcome. This observation shows a need for modification of the materials contained in calcium sulfate paste.

• 한국세라믹학회지
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• 제24권4호
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• pp.343-348
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• 1987

The effects of salts such as aluminum sulfate as inorganic salt(2-4%), and sodium salts of citrate, tartrate, succinate, potassium tartrate and gelatin as organic salts(0.1%) on the formation of ${\alpha}$-calcium sulfate hemihydrate from by-product gypsum of phosphoric acid process under hydrothermal condition at 123$^{\circ}C$ and 133$^{\circ}C$ were investigated. Aluminum sulfate solution exhibited the catalystic effected on the crystallization of ${\alpha}$-calcium sulfate hemihydrate of which was assumed in the prismatic form, and organic salts solution exhibited little effect on the catalystic action to the crystallization, than inorganic salts. In the acidic solution with sulfuric acid(pH=2), needle like crystal of calcium sulfate hemihydrate was obtained. Hydrothermal process with aluminum sulfate solution also showed certain amounts of impurity removal such as phosphorus penataoxide from calcium sulfate hemihydrate.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.219-237
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• 1998

Numerous bone graft materials have been used in Periodontics, in an attempt to reach the main goal of periodontal therapy, i.e. the regeneration of periodontal tissue lost due to destructive periodontal diseases. The present study investigates the effect of composite graft of DFDB and Calcium sulfate with and without Calcium sulfate barrier in Periodontal 1-wall intrabony defects in dogs. Following the initiation of general anesthesia by I.V. administration of 40mg/Kg of Pentobabital, second premolar was extracted and full thickness flap elevated. The crown portion of premolars was removed. Exposed root canals were sealed with Caviton and covered completely with flap. After the healing period of 8 weeks, the surgical sites were re-opened and 1-wall intrabony defects were created, and treated with flap operation alone(control group), with composit graft of 80% DFDB and 20% Calcium sulfate(Experimental group 1), with composite graft of DFDB and calcium sulfate with calcium sulfate membrane( Experimental group 2). Healing response was histologically observed after 8 weeks and the results were as follows : 1. New bone formation was 70 % in the control group, 93 % in the Experimental group I, 89 % in the Experimental group II. There was a no differences between Experimental groups. 2. New cementum formation was not significantly different between control and two Experimental groups. 3. The length of connective tissue adhesion was 30 % in the control, 7% in the Experimental group I and 11 % in the Experimental group II. 4. After 8weeks, calcium sulfate was completely resorbed, while DFDB particle remained. These results suggest that the use of composite graft of allogenic DFDB and Calcium sulfate with and without Calcium sulfate barrier in periodontal 1 wall intrabony defects have little effect on connective tissue adhesion, but has beneficial effect on new alveolar bone and new cementum formation, and prevent downgrowth of epithelium and connective tissue effectively.

• Advances in concrete construction
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• 제11권3호
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• pp.183-192
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• 2021

Due to economic and environmental benefits, increasing the substitution ratio of ordinary cement by industry by-products like fly ash (FA) is one of the best approaches to reduce the impact of the concrete industry on the environment. However, as the substitution rate of FA increases, it will have an adverse impact on the performance of cement-based materials, so the actual substitution rate of FA is limited to around 10-30%. Therefore, in order to increase the early-age strength of high replacement (30-70%) low-calcium ultrafine FA blended cement paste, sodium sulfate and calcium sulfate dihydrate were used to improve the reactivity of FA. The results show that sodium sulfate has a significant enhancement effect on the strength of the composite pastes in the early and late ages, while calcium sulfate dihydrate has only a slight effect in the late ages. The addition of sodium sulfate in the cement-FA blended system can enhance the gain rate of non-evaporation water, and can decrease the Ca(OH)2 content. In addition, when the sulfate chemical activators are added, the ettringite content increases, and the surface of the FA is dissolved and hydrated.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.153-171
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• 1999

The purpose of this study was to evaluate the effect of modified calcium sulfate paste on periodontal regeneration. l-wall intrabony defect(mesio-distal width: 4mm, depth: 4mm) was surgically created on the distal side of P2 and mesial side of p4 in four dogs. The control group(GFS) was treated with conventional flap operation alone, and the experimental group(CS) was treated with conventional flap operation with modified calcium sulfate paste application. Both control and experimental groups were sacrificed after 8weeks of healing period, The results of histological and histometric observations were as follows. 1. The length of the junctional epithelium was 0.41${\pm}$0.01mm in the control groups, 0.47${\pm}$0.01mm in the experimental group. 2. The connective tissue attachment was 0.28${\pm}$0.02mm(6.15${\pm}$0.28%) in the control group, 0.18${\pm}$0.01mm(3.41${\pm}$0.14%) in the experimental group. The control group showed more connective tissue attachment. 3. The new cementum formation was 3.80${\pm}$0.06mm(84.80${\pm}$0.33%) in the control group, 4.49${\pm}$0.06mm(87.57${\pm}$0.15%) in the experimental group. Both groups showed a lot of new cementum formation. 4. The new bone formation was 1.43${\pm}$0.03mm(32.37%) in the control group, 2.04${\pm}$O.09mm(40.94%) in the experimental group. 5. The inflamatory cells were observed partially around resorbed calcium sulfate in the connective tissue of the experimental group. 6. Partially resorbed calcium sulfate were found within the connective tissue, around alveolar bone, and in the newly formed alveolar bone, On the basis of these results, newly formed calcium sulfate paste enhanced new bone formation and new cementum formation. The resorption rate of calcium sulfate seems to be controlled by the add-in compounds. Thus research about biocompatibility and adequate resorptionrate is required to develop a improved material.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.18-19
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• 2017

In this study, hardening characteristics and microstructure of blast furnace slag-cement mortar replaced alpha-calcium sulfate hemihydrate were analyzed. As a result of replacing alpha-calcium sulfate hemihydrate with 0, 10, 20, 30%, it was confirmed that the initial and final setting times are faster than that of blast furnace slag-cement mortar. The compressive strength of the specimens containing alpha-calcium sulfate hemihydrate decreased in the range of 42 ~ 76% at age 28 days compared with blast furnace slag-cement mortar. In the case of replacing the alpha-calcium sulfate hemihydrate, the shrinkage did not occur more rapidly than the cement mortar, but the slope of the strain curve showed a linear behavior. The results of scanning electron microscopy images analysis showed that the formation of ettringite was increased at alpha-calcium sulfate hemihydrate replaced mortar.