• Restorative Dentistry and Endodontics
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• 제44권4호
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• pp.45.1-45.10
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• 2019

Objectives: Self-adhesive resin cements contain functional monomers that enable them to adhere to the tooth structure without a separate adhesive or etchant. One of the most stable functional monomers used for chemical bonding to calcium in hydroxyapatite is 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). The aim of this study was to evaluate the influence of the10-MDP concentration on the bond strength and physical properties of self-adhesive resin cements. Materials and Methods: We used experimental resin cements containing 3 different concentrations of 10-MDP: 3.3 wt% (RC1), 6.6 wt% (RC2), or 9.9 wt% (RC3). The micro-tensile bond strength of each resin cement to dentin and a hybrid resin block (Estenia C&B, Kuraray Noritake Dental) was measured, and the fractured surface morphology was analyzed. Further, the flexural strength of the resin cements was measured using the three-point bending test. The water sorption and solubility of the cements following 30 days of immersion in water were measured. Results: The bond strength of RC2 was significantly higher than that of RC1. There was no significant difference between the bond strength of RC2 and that of RC3. The water sorption of RC3 was higher than that of any other cement. There were no significant differences in the three-point bending strength or water solubility among all three types of cements. Conclusions: Within the limitations of this study, it is suggested that 6.6 wt% 10-MDP showed superior properties than 3.3 wt% or 9.9 wt% 10-MDP in self-adhesive resin cement.

• 대한치과의사협회지
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• 제22권9호통권184호
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• pp.803-811
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• 1984

The purpose of this study was to research how temporary cementation effected on the bond strength of permanent cementation. Zinc phosphate, polycarboxylate and EBA ZOE cements were used as permanent cements, and as temporary cements Nogenol, Tempak and Dycal were used. The ninety six (96) specimens were prepared to measure the bond strength of permanent cements after treated with temporary cements for one week. The tensile stregths were measured with an Instron Universal Test Machine. The results of this study were obtained as follows: 1. With zinc phosphate cement, there was a tendency that the bond strengths of the group of temporarily cemented with Nogenol were increased, meanwhile they were decreased a little in the groups of Dycal and Tempak than those of the control group. 2. With polycarboxylate cement, there was a tendency that the bond strengths of the Control group were higher than those of experimental groups and they were decreased in order of Tempak, Noginol, and Dycal. 3. With EBA ZOE cement, there was a tendency that the bond strengths of the group of temporarily cemented with Tempak were increased a little, meanwhile they were decreased a little in the groups of Nogenol and Dycal than those of the Control group. 4. Among the permanent cements, the bond strengths of polycarbosylate cement were the highest and were followed in order of zinc phosphate cement and EBA ZOE cement.

• 대한치과보철학회지
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• 제8권1호
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• pp.90-94
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• 1968

The author attempted to study the role of liners as a barrier against the penetration of the acids released from the liquid of dental cements. Six different kinds of liners were used in this study and the depth of penetration of the acids of phosphate and silicate cements were measured ands following conclusions were obtained. 1. All the liners successfully prevented penetration of the acids released from phosphate and silicate cements. 2. When silicate cements were placed into the cavity without any liners, free acids were liberated continuously and thus may give injuries to the pulp tissue.

• 대한심미치과학회지
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• 제8권1호
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• pp.76-82
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• 1999

Zinc phosphate cement has long been the material of choice for permanent luting of cast restorations, and through many years of use has been considered effective to retain castings. However, cast restorations cemented with this material have been susceptible to secondary caries. Glass ionomer luting agents become available in the late 1970s. These material s, through release of fluoride, show considerable promise as a means of reducing secondary caries. Other favorable traits include significantly less disintegration in vivo than zinc phosphate cements, a film thickness comparable to that of zinc phosphate cement, and adhesion to tooth structure. Compomer materials were created in 1993 as a filling material for deciduous teeth, cervical lesions, and class III cavities. In the meantime, compomer have been developed as chemical hardening cements for cast gold restorations. The aim of this paper is to review the articles on luting cements to help the choice of dental cements.

• 대한치과보철학회지
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• 제9권1호
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• pp.41-45
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• 1969

A major disadvantage of Dental cements is their solubility. So it is very important to measure the exact amount of solubility to select clinically suitable materials. The most common laboratory test for solubility is the measurement of disintegration in distilled water, as outlined in A.D.A. Specifications 8 and 9, In addition to the possible factors influencing the solubility, the experiments were all conducted in compliance with A.D.A. Specifications. The solubility of 2 Zinc Phosphate cements and 1 Silicate cement in time of dissolution, concentration of solute in dissolving medium, and type of dissolving medium were investigated. The following results were obtained. 1. Generally the materials were more soluble in organic acids than in distilled water. 2. The dissolution cements tends be minimized by tests utilizing prolonged storage in the same media. 3. In Acetic acid solution, Zinc Phosphate cements were more soluble than Silicate cement, and in Citric acid solution both were markedly more soluble. 4. Solubility was increased by continually presenting fresh liquid, unsaturated with solute, to the cement-water interface.

• 대한치과의사협회지
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• 제11권1호
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• pp.41-44
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• 1973

The experiment consisted of cementing full veneer crown of extracted teeth and a standardized cylindrical metal dies (6mm diameter, 6mm height, 1mm shoulder) and then measuring the tensile strength required to remove the cemented restoratoins by the Instron testing machine in the Korea Institude of Science and Technology. The Instron machine was operated at a rate of loading of 0.2cm per minute. From the experiments, the following results obtained. 1. The tension of zinc phosphate and alumina EBA cements were highest all of the cements. 2. The tension of Fynal and the addition of eugenol to zinc Phosphate cements were similar. The addition of eugenol to zinc phosphate cement was half stength and Fynal cement was on third strength than zinc phosphate cement. 3. The tension of zinc oxide-eugenol cement was lowest all of the cements.

• 대한치과보철학회지
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• 제14권1호
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• pp.17-21
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• 1976

The author studied the gingival responses to some dental cements in the gingival sulcus around artificial crowns. Abutment preparation for full veneer crown was performed in the canines of the two dogs. The location of cervical margins was about 0.5mm. below the gingival crest. Niranium metal crowns were constructed for the teeth, and cemented with zinc phosphate cement or polycarboxy late cement. In the experimental groups the retained cements in the gingival sulucus were not removed, and in the control groups the cements were removed completely after cementation. The dogs were sacrificed at 3 weeks and 5 weeks respectively after cementation. The gingival responses to these cements were examined histologically. The findings were as follows. 1. There was severe inflammation in the gingiva where the cements had been retained in the gingival sulcus around artificial crowns. 2. There was more severe inflammation in the gingiva which had contacted with zinc phosphate cement than in the gingiva with polycarboxylate cement. 3. There was mild inflammation in the gingiva around the margins of Niranium crowns. 4. The retained cement around the margin of restoration should be completely removed after cementation.

• 한국세라믹학회지
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• 제34권10호
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• pp.1027-1036
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• 1997

The reology and several physical properties of cements are studied by varying the different mineral composition and particle size distribution(PSD) of cements with closed circuit ball mill for high workability, low heat of hydration, and high strength. In this study, we found that the workability of concretes is related to the viscosity of cement, and affects to strength. Here, this workability is affected by mineral composition (C3A) and the PSD. Especially, rosin-rammer index and 44${\mu}{\textrm}{m}$ residue in the PSD of cements are affected to water demand, casting property, slump loss, strength of cements. From the above results, the conditions of cement for high workability, low heat of hydration and high strength are to use low C3A clinker, 5-10% slag addition, and to grind cement below 0.7 rosin-rammer index, above 3.5-4.5% 44 ${\mu}{\textrm}{m}$ residue, 4000$\pm$100 $\textrm{cm}^2$/g blaine. Such cements are, therefore, supurior to super low heat cement and slag-blended cement in comparing the physical properties of strength, slump, slump-flow, adiabetic temperature, etc.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.792-800
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• 1997

The purpose of this study was to evaluate the adaptation of self-cured glass ionomer cement and resin-modified glass ionomer cement and polyacid-modified resin composite, which are light-cured giass ionomer cements, to dentin surface. Twelve extracted human maxillary and mandibular molar teeth were used in this study. The entire occlusal dentin surfaces of teeth were exposed with Diamond Wheel Saw and smoothed with sand papers (300, 600, 1200grits). They were randomly assigned into 3 groups according to glass ionomer cements used; Control group- Fuji II, Expeimental group 1 - Fuji II LC, Expeimental group 2 - Dyract. According to the manufacturer's directions, three glass ionomer cements were bonded to exposed dentin surfaces of the tooth crown and cured. Crowns and glass ionomers were trimmed after 24hrs and sectioned horizontally and vertically with diamond saw. The interface of glass ionomer cements and dentin was examined under SEM. The results were as follows : 1. Good adatation between glass ionomer cement and dentin on the horizontal section was showed in control and experimental group 1, but the gap of $20{\mu}m$, which was observed distinct separation between glass ionomer cement and dentin, was showed in experimental group 2. 2. Good adatation between glass ionomer cements and dentin on the vertical section was showed in control and experimental group 1, but the gap of 80-$100{\mu}m$ was showed in experimental group 2. 3. Cohesive fracture within glass ionomer cements in control and experimental group 1 was showed, but no cohesive fracture was showed in experimental group 2.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.190-199
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• 1991

The purpose of this study was to evaluate the antimicrobial effect of root canal cements such as AH-26, Sealapex, Canals and Apatite root sealers(Type I, II, III) and to determine the efficacy of their activities. S.mutans(AHT), S.sanguis(NCTC 9811) and B.gingivalis(381) were streaked on blood agar and the PVC tybes filled with root canal cements were applied on. Then the microorganisms were cultured for 48 hours, anaerobically. B.cereus(KCTC 1012) was streaked on nutrient agar, PVC tubes were applied on and were cultured for 48 hours, aerobically. The inhibition zones of root canal cements were measured with vernier caliper. The data statistically analyzed, and the results were as followed. 1. Apatite root sealers(Type I, II, III) showed no inhibition zones. 2. AH-26, Sealapex and Canals had inhibition zones with varying degrees. The inhibition zone of AH-26 was greatest and followed by Canals and Sealapex(P<0.01). 3. As time goes by after mixing the root canal cements, AH-26, Canals and Sealapex showed significantly reducing inhibition zones(P<0.01). 4. There were the least inhibition zones of all the root canal cements on S.mutans and followed in such order as; B.gingivalis, S.sanguis and B.cereus(P<0.01).