• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.130-136
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• 1994

Toothash and plaster of Paris (Calcium sulfate) have been studied for bone substitute through experimental studies and clinical studies. Toothash is like resorbable hydroxyapatite. Plaster of Paris is resorbable and biocompatible. The toothash combined with plaster of Paris has the advantages of individual characteristics. The authors used this composite material in the jaw defect filling. In operation, we could manage this implant material easily and remove the dead space. During the followup period, this composite material was resorbed gradually and substituted as new-forming bone from the surrounding tissue. Complications were minor and treated completely without problems.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.493-505
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• 1999

Purpose: This study was to evaluate the effects of Aloe. Gelfoam. and Plaster of Paris on bone healing. Materials and Methods: Four experimental defects were created for placement of the three materials in the right femur of dogs. One defect served as an empty control site. The evaluation was performed at 1-. 6-. and 12-weeks by light microscopy and radiographs. Results: Radiographic and histologic examinations showed new bone formation in the presence of Aloe, Gelfoam. and Plaster of Paris and similar bone healing reactions. Conclusion: On the basis of these findings, it was concluded that Aloe, Gelfoam. and Plaster of Paris may be adequate agents for use in bone procurement.

• Journal of the Korean Ceramic Society
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• v.31 no.10
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• pp.1107-1114
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• 1994

Although various theories have been presented on the mechanism of setting retardation of plaster in addition to organic admixtures. The purpose of this paper is that Hydration studies of plaster of paris in the presence of carboxylic acids under alkalinity are examined in the coordination chemistry. Setting of plaster of paris is retarded by the addition of carboxylic acids except oxalic acid. And setting of plaster of paris contained 5 wt% of Ca(OH)2 is also retarded by the addition of above-mentioned carboxylic acids. The degree of retarding effect under alkalinity is found to be a function of the number of the functional group and the length of carbon chain of carboxyl acids. These reasons are attributed to the soluble complex formation, that is calcium complex formation between calcium ion and carboxylic acids. The author's proposal was confirmed by the results of electrical conductivity measurement. The formation of calcium complex was surpported by IR spectra.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.771-777
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• 1996

This study was undertaken to access the effect of toothash combined with plaster of Paris in the filling of jaw defect and the substitution as new bone during the follow up period. We used the toothash and plaster after the cyst enucleation, the apicoectomy, the extraction of supenumerary tooth with ratio of 2 : 1 by weigh. 15 consecutive patients were evaluated retrospectively. Complications were swelling, perforation, infection and treated without problems using incision & drainage, aspiration, antibiotic treatment, 2ndary buccal flap. The follow-up period ranged from 28 to 35 months. Based on radiographic and clinical observation, it may be concluded that toothash and dental plaster of Paris($CaSo_4\;{\cdot}\;1/2H_2O$) are useful for bone substitute.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.1
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• pp.27-35
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• 2006

Purpose: This study was performed to investigate the expression of the transforming growth factor (TGF)-1, in a rat calvarium defect model using particulate dentin and/or plaster of Paris, and correlate the bone regeneration process with the histologic events. Materials and Methods: Thirty-two Sprague-Dawley rats were divided into 4 groups of 8 animals each. A 1.0 cm-sized calvarial defects were made and the defect was filled with different graft materials as follows : Group A, the defects were filled with a mixture of particulate dentin and plaster of Paris with a 2:1 ratio; Group B, the defects were filled with plaster of Paris only; Group C, defects were filled with particulate dentin only; Group D, untreated control group. The animals were sacrificed by 1, 2, 4, 8 weeks after implantation. Excised wound tissues were processed for histology, immunohistochemistry and RT-PCR for the analysis of TGF-1 expression. Results: Gene expression of TGF-1 was detected for all experimental groups. The highest gene expression was observed in the specimen taken at the first week after implantation in Group A. According to the histologic and immunohistochemical studies, TGF-1 positive osteoblast-like cells were found in the early stage of healing after the implantation of particulate dentin and plaster of Paris. Conclusion: These findings suggest that TGF-1 may be related to new bone formation at the early healing process after the implantation of particulate dentin and plaster of Paris.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.26-32
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• 1996

This study was performed to determine the ideal mixing ratio of toothash and plaster of Paris. The histopathologic and histomorphometric study of bone response of five implant materials, toothash(Group A), tooth and plaster mixture, mixing ratio due to weight 2 : 1(Group B), 3 : 1(Group C), 4 : 1(Group D), and plaster Paris(Group E), were performed in rat calvarial defect. No sign of extensive inflammatory reaction was defected. Newly-formed bony ingrowth occurred in all experimental groups except for group E at 12 weeks after operation. Bone was deposited directly on the surface of implant materials. The highest rate of direct bony union between implant material and newly-formed bone occurred with the group B, followed group C, D, and A.

• The Journal of the Korean dental association
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• v.13 no.2
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• pp.133-136
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• 1975

The autor studied skin reactions and their incidences among 130 dental students and dentists to 2% Iidocaine HCI, 2% procaine HCI, direct resin, plaster of paris, zinc oxide-eugenol cement, and adhesive plaster by Patch test. The results of the studies are as follows: 1. Eighteen cases out of 130 revealed slight positive reaction toa 1 or 2 allergens. 2. Lidocaine HCL showed 1 case, procaine HCL 4 cases, direct resin 4 cases, Z.O.E. cement 1 case, adhesive plaster 13 case, and plaster of paris showed none. 3. Two delayed reaction were detected after 48 hours, one of which reacted both lidocaine HCL and direct resin, and the other one was a case of adhesive plaster.

• Advances in environmental research
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• v.2 no.1
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• pp.35-49
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• 2013

Research work on removal of fluoride from water, referred to as water defluoridation, has resulted into the development of a number of technologies over the years but they suffer from either cost or efficiency drawbacks. In this work, enhancement effects of phosphate and silicate on defluoridation of water by low-cost Plaster of Paris (calcined gypsum) were studied. To our knowledge, the influence of silicate on defluoridation was not reported. It was claimed, that the presence of some ions in the treated water samples, was decreasing the fluoride removal since these ions compete the fluoride ions on occupying the available adsorption sites, however, phosphate and silicate ions, from its sodium slats, have enhanced the fluoride % removal, hence, precipitation of calcium-fluoro compounds of these ions can be suggested. Percentage removal of $F^-$ by neat Plaster is 48%, the electrical conductance (EC) curve shows the typical curve of Plaster setting which begins at 20 min and finished at 30 min. The addition of phosphate and silicate ions enhances the removal of fluoride to high extent > 90%. Thermodynamics parameters showed spontaneous fluoride removal by neat Plaster and Plaster-silicate system. The percentage removal with time showed second-order reaction kinetics.

• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.66-67
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• 2005

• The Journal of the Korean dental association
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• v.36 no.4 s.347
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• pp.289-295
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• 1998

Toothash and Plaster of Paris(Calcium sulfate) mixture have been studied for development of new biomaterial since 1992. I have performed the experimental and clinical study for evaluation of biocompatibility and possibility of bony defect reconstruction and clinical application. These materials are biocompatible, osteoconductive and resorbable. Main component of toothash is hydroxylapatite. In the future, I will perform the systematic construction of material and additional research.