• The Journal of the Korean dental association
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• v.11 no.1
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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.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.1
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• pp.93-101
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• 1992

The purpose of this study was to evaluate the effectiveness of core materials and luting agents on the retention of full veneer gold crown. The core materials used in this study was dental amalgam, and composite resin, and the luting agents were zinc phosphate cement, polycarboxylate cement, and glass ionomer cement. The obtained results were as follows. 1. In full veneer gold crown supported by composite resin core, the crown retention with zinc phosphate cement was the highest of all. 2. In full veneer gold crown supported by amalgam core, the crown retention was shown no statistical difference by luting agent. 3. There was no statistical difference in the crown retention between the full veneer gold crown supported by composite resin core and dental amalgam core.

• Journal of Korean society of Dental Hygiene
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• v.2 no.1
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• pp.115-129
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• 2002

The purpose of this study was to examine the actual dental hygiene status of workers in cement industry in an effort to serve as a basis for enhancing their dental hygiene. The subjects in this study were 420 laborers from the cities of Curi, Donghae and Samcheok who handled cement. As a result of conducting a survey, the following findings were given : l. The workers investigated found their working environment satisfactory, getting a mean score of 323. They also expressed a high job satisfaction with a mean score of 333. 2. They didn't have a big interest in oral health. By age group, those who were aged between 36 and 40, or who cared less about health management, showed a higher interest in oral health. Besides, the laborers who kept smoking for a longer period, or who drunk more, expressed greater interest. 3. The toothbrushing method was considered most important for periodontal health, by 45.0% of the workers, and the next most crucial one was regular dental examination, followed by refraining from smoking and staying away from sweet food in the order named. 4. Concerning daily mean toothbrushing frequency, 455% brushed their teeth three times a day on the average. More than half them didn't pay enough attention to toothbrushing. 5. Regarding scaling, the large number of the workers, 42.4%, had no experience to get their teeth scaled, 37.6%, the greatest percentage, didn't have their teeth scaled because it seemed to make their teeth painful or cold. 6. As fororal health education experience, 67.6%, the great number of them, had no experience to receive dental health education. The above-mentioned findings suggest that the cement-related workers generally neglected dental health management. They should be encouraged to correct their wrong oral health knowledge or habit to make their oral cavity more healthy. To make it happen, it's required to provide oral health education and promote organized dental health projects.

• Journal of Technologic Dentistry
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• v.46 no.1
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• pp.1-7
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• 2024

Purpose: The goal of this study was to determine the clinical acceptability of various cement space settings for the marginal and internal fit of a zirconia core manufactured using additive manufacturing. Methods: The maxillary right incisor served as the master model. After scanning the maxillary right incisor with a dental 3D (three-dimensional) scanner, the stereo lithography file was created using different cement space settings of 40, 120, and 200 ㎛ using computer-aided design software (Dental System 2018; 3Shape). The marginal and internal fit of the 3 groups were determined using the silicon replica technique. Measurement points were divided into the following three categories: margin, axial wall, and incisal. To ensure more accurate measurements, these three measurement points were divided into 8 points. The Shapiro-Wilk, one-way ANOVA, and Tukey's honestly significant difference test (for all tests α=0.05) were the statistical analyses that were included in the study. Results: The CS (cement space)-200 group had better marginal and internal fit than the CS-40 and CS-120 groups, and there were statistically significant differences at the marginal and incisal points, except for the axial wall points. CS-200 group, both marginal and internal fit were within 120 ㎛, which is the clinically acceptable value. Conclusion: This study suggests that a 200 ㎛ cement space setting is ideal for optimal marginal and internal fit of 3D-printed ceramic crowns.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.433-442
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• 1998

The purpose of this study was to observe the changes of acidity of resin cement(Time Line), glass ionomer cement(GC Fugi Lining LC), zinc phosphate cement(Fleck's zinc cement). zinc oxide eugenol cement(Sultan,Chemists.) in vivo and in vitro. Class I cavities with 3mm depth were prepared on the occlusal surfaces of 20 recently extracted human Mn. molar teeth and 20 human Mn. 3rd molar teeth in oral cavity. The prepared cavities were divided into 4 groups of each 5 teeth using the above 4 cavity liners. Each cement was mixed in accordance with manufacturer's direction at the room temperature of $23^{\circ}{\pm}5^{\circ}C$ and filled into the cavity in a width of 1 mm. The microelectrode of pH meter was inserted into the prepared cavity which was filled with mixed cement, and the acidity of cement was measured for 3 days from the beginning of cement mix in vitro and in vivo. The measured acidity was then statistically analyzed by ANOVA. The results were as follows. 1. In vitro, the pH of zinc oxide eugenol cement was statistically lower than that of the three other groups at 2min, 4min, 6min, 8min, 10min, 12min, 18min, 20min. (p<0.05). 2. The pH of zinc oxide eugenol cement in vivo was statistically higher than that in vitro at 16min,16min, 20min(p<0.05). 3. The pH of zinc phosphate cement in vivo was statistically higher than that in vitro at 4min, 20min(p<0.05). 4. In vitro and in vivo, there was no significant difference in the pH between the resin cement and the glass ionomer cement(p>0.05). 5. The initial acidity was not high, but almost neutral in all kinds of the cements.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.235-242
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• 2017

Purpose: The aim of this study was to evaluate the marginal and internal gap of zirconia copings fabricated by CAD/CAM system and to research the effect of cement space on the fit of zirconia prosthesis. Methods: Zirconia copings were designed using 3shape software and then milled from presintered zirconia blocks by Kavo dental milling machine. The cement space was set at $0{\mu}m$ around the margins for all groups, and additional cement space appling 1 mm above the finish lines of tooth. The samples were classified into 4 groups according to the cement space setting(Cs-0, Cs-40, Cs-80, Cs-120). Replica technique used to investigate marginal and internal gap. The silicone film thickness was recorded using a optical microscope with image software analysis system at 75${\times}$magnification. The assessment performed on the six points in bucco-lingual and mesio-distal sections(4 groups, 10 copings per group, 12 measuring points per coping). The data were statistically analyzed with one-way ANOVA followed by pair-wise Tukey's post hoc tests(${\alpha}$<0.05). Results: Better marginal and internal fit values were exhibited by $80{\mu}m$ cement space. The results showed that different cement space values had statistically significant effect on the marginal and internal gap of zirconia copings(p<0.001). The gap of margin and axial wall area was smaller than that the gap of occlusal area in all groups(p<0.001). Conclusion : Effect of different cement spaces on the marginal and internal gap of zirconia copings.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.167-175
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• 2016

Objectives: Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods: Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results: The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions: Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.475-483
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• 2015

PURPOSE. The objective of this study was to evaluate the influence of various cement types on the stress distribution in monolithic zirconia crowns under maximum bite force using the finite element analysis. MATERIALS AND METHODS. The models of the prepared #46 crown (deep chamfer margin) were scanned and solid models composed of the monolithic zirconia crown, cement layer, and prepared tooth were produced using the computer-aided design technology and were subsequently translated into 3-dimensional finite element models. Four models were prepared according to different cement types (zinc phosphate, polycarboxylate, glass ionomer, and resin). A load of 700 N was applied vertically on the crowns (8 loading points). Maximum principal stress was determined. RESULTS. Zinc phosphate cement had a greater stress concentration in the cement layer, while polycarboxylate cement had a greater stress concentration on the distal surface of the monolithic zirconia crown and abutment tooth. Resin cement and glass ionomer cement showed similar patterns, but resin cement showed a lower stress distribution on the lingual and mesial surface of the cement layer. CONCLUSION. The test results indicate that the use of different luting agents that have various elastic moduli has an impact on the stress distribution of the monolithic zirconia crowns, cement layers, and abutment tooth. Resin cement is recommended for the luting agent of the monolithic zirconia crowns.

• 대한치과교정학회:학술대회논문집
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• 1997.11a
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• pp.34.1-34.1
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• 1997

• The Journal of Korean Academy of Prosthodontics
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• v.13 no.1
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• pp.23-26
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• 1975

The purpose of this study was to measure the retentive force of various kinds of dental cement. Cross-cutting the half of the occlusal surface, pinholes were prepared on the dentin with No. 557 carbide bur. No. 557 steel burs were cemented in the pinholes and retentive force was measured by removing the burs with Instron testing machine. The Instron testing machine was operated at a rate of 0.2 cm per minute. The following results were obtained : 1. The retentive force of zinc phosphate cement(A), reinforced zinc oxide and eugenol cement and polycarboxylate cement were similar to each other, but that of zinc phosphate cement (A) was the highest of all. 2. The retentive force of zinc phosphate cement (B) was the lowest of all.