• 대한소아치과학회지
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• 제26권3호
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• pp.528-537
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• 1999

Stainless steel crown은 소아치과 영역에서 가장 효과적이면서 신뢰할 수 있는 수복방법으로 그 사용이 확대되는 추세이다. 선학들의 연구에 의하면, stainless steel crown의 장착에 있어서 시멘트를 사용한 경우가 사용하지 않은 경우보다 8배 이상의 유지력을 얻을 수 있으므로, stainless steel crown 시술에 있어서 시멘트는 중요한 부분이라고 할 수 있다. 본 연구는 stainless steel crown의 접착을 위하여 임상적으로 흔히 사용되는 인산아연 시멘트, 폴리카복실레이트 시멘트, 접착용 글래스 아이오노머 시멘트의 접착력을 비교분석 할 목적으로 시도되었다. 인산아연 시멘트로 FLECK'S, 폴리카복실레이트 시멘트로는 HY-Bond, 접착용 글래스 아이오노머 시멘트로는 Vitremer, stainless steel로는 Sun-Platinum plate를 사용하였다. Bovine teeth, 글래스 아이오노머 시멘트(Fuji II LC), 아말감(Valiant)상에 3종의 시멘트로 형성된 기둥을 세워 양자간의 접착력을 측정하였고, 한편으로는 stainless steel plate 상에 3종의 시멘트 기둥을 세워 또한 양자간의 인장접착 강도를 만능시험기로 측정하였다. 측정치를 ANOVA와 Student t-test로 통계 처리하여 다음과 같은 결과를 얻었다. 1. Stainless steel crown에 대해 글래스 아이오노머 시멘트와 폴리카복실레이트 시멘트가 인산아연 시멘트보다 높은 인장결합강도를 보였고, 글래스 아이오노머 시멘트와 폴리카복실레이트 시멘트 사이에는 차이가 없었다. 2. Bovine teeth와 수복용 글래스 아이오노머 시멘트에 대해서는, 접착용 글래스 아이오노머 시멘트가 가장 높은 인장결합강도를 보였고, 다음으로 폴리카복실레이트 시멘트와 인산아연 시멘트의 순이었다. 3. 아말감 수복재에 대해서는, 폴리카복실레이트 시멘트와 글래스 아이오노머 시멘트가 인산아연 시멘트보다 높은 인장결합강도를 보였고, 폴리카복실레이트 시멘트와 글래스 아이오노머 시멘트 사이에는 유의한 차이가 없었다.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.429-447
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• 1995

This study was designed to determine the most effective concentration of fluoride and levels of laser irradiation for the remineralization of decayed teeth. After irradiation with a pulsed Nd:YAG laser and the topical application of fluoride, phosphate and fluoride concentration in enamel were measured. And then the changes on surface enamel using an scanning electron microscope were observed. Samples by extraction healthy, permanent, mandibular bovine teeth with no caries were obtained. Among them 371 healthy samples were selected and artificial carious lesions were made. 20 samples were assigned to each experimental group. After irradiation with a pulsed Nd:YAG laser with total energy densities of 10J/$\textrm{cm}^2$, 20J/$\textrm{cm}^2$ for each group. On the teeth, 2% NaF, 1.9% NH4F, 1.6% TiF4 Elmex gel(amine fluoride) and 1.23% APF gel were applied. After pH circulatory procedures, concentrations of fluoride with and Ionalyzer (Orion Research, Model 901, USA) and phosphates with an Uv/V is spectrophotometer (Uvikon 860, Kontrom Co, Switzerland) were measured. By etching the teeth in layers and measuring fluoride concentrations, a profile of fluoride penetration according to depth could be developed. And also the changes on the surface of the enamel using an electron scanning microscope were observed. The comparative analysis yielded the following results : 1. Phosphate concentration was low in all groups compared with the control group except for teeth treated Elmex gel, irradiated with 10J/$\textrm{cm}^2$ and 30J/$\textrm{cm}^2$ energy densities. Teeth treated with APF gel and 30J/$\textrm{cm}^2$ irradiation gad the lowest phosphate concentration. 2. Among all groups, fluoride concentrations in tooth enamel were highest in APF gel and NaF groups irradiated at 30J/$\textrm{cm}^2$. The APF gel group had the highest fluoride concentrations across all energy densities. 3. In the APF gel group, and the NaF group, the greater the energy density of the laser, the higher the fluoride concentrations in the enamel. 4. In all groups, the concentration of fluoride in the enamel by depth tended to decrease with depth. 5. Under the scanning electron microscope, under the condition of irradiation with 20J/$\textrm{cm}^2$, enamel crack was detected for the first time. In the NH4F group, spherical deposits were found on the surface of the enamel, and in the TiF4 group the surface of enamel was covered with an irregular, thin membranous mass in places. In the APF gel and NaF groups irradiated with 10J/$\textrm{cm}^2$, spherical and irregular particles covered the teeth. When these groups were irradiated at 20J/cm2, they were covered with amorphous crystals. These results suggest that one could obtain more effective anticariogenic effects without damage to teeth when less than 20J/$\textrm{cm}^2$ energy densities and APF gel are used.

• 대한치과교정학회지
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• 제23권1호
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• pp.75-88
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• 1993

Recent reports indicate that shorter etching times than 60 seconds can be adopted without affecting the bond strength and clinical disadvantages. The purpose of this in vitro study was to compare the shear bone strength and to measure depth of etch at different etching time length. One hundred and eight extracted bovine lower central incisors were embedded each in a tooth cup with cold-cure acrylic resin. The facial surfaces of the teeth were ground wet with 600-, 800-, 1000-, and 1200-grit Sic papers, and finally polished with a water slurry of extrafine silicon carbide powder, washed with tap water, and dried with hot air. Nine groups of nine prepared teeth were etched with a commercial($38\%$ phosphoric acid solution) for 0, 5, 10, 15, 20, 30, 60, 90, and 120 seconds, respectively, rinsed with tap water, and dried with hot air. One conditioned teeth from every group was selected randomly for the scanning electron microscopic examination, and the remaining eight teeth of the groups were used for measuring the push shear bond strength after bonding brackets and immensing them in the $36.5^{\circ}C$ water for 24 hours. Another nine groups of three teeth were used for measuring the depth of etch and surface roughness with a surface profilometer. after pieces of adhesive tape of 3mm inner diameter positioned on the ground enamel surfaces, and etched with the above mentioned. The data obtained form the above expeiments were analysed statistically with one way ANOVA and Dunkan's multiple range test with the $95\%$ confidence level. The results and conclusion of the study were as follows; 1. The results of shear bond strength for the given experimental etching times were not statistically different, but showed the tendency of decreasing shear bone strength after over 60 seconds etching times. 2. On the scanning election microscopic examination, it was observed that the morphological patterns of etched enamel surface for 5 to 20 seconds were similar and consitent, and those for 30 to 120 seconds showed increasing over-etched patterns depending on the length of etching times. 3. The depth of etch was increased almost proportionally by the length of etching times, but it was not associated with the shear bond strength. 4. The surface roughness increased depending on the length of etching times, but it was not associated with the shear bond strength. 5. This experiment indicated that proper etching time with $38\%$ phosphoric acid solution is in the range of 5 to 30 seconds.

• 치위생과학회지
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• 제23권3호
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• pp.236-244
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• 2023

Background: The size of the tooth whitening market and toothpaste market is increasing worldwide. The purpose of this in vitro study is to confirm and compare the coffee stain removal effects of commercial whitening toothpaste in sound and demineralized teeth, respectively. Methods: A total of 112 flat permanent bovine teeth specimens were manufactured. Half of the surface of the specimen was coated with an acid-resistant varnish and deposited in an artificial demineralizing solution for 65 hours. The varnish applied to half of the specimen was removed and deposited in a coffee solution for 96 hours to induce coloring. Two control and five experimental group toothpastes for teeth whitening were selected and the main components were investigated. Toothbrushing was performed 50, 100, and 150 times for each toothpaste group. A total of four images were obtained: before the start and after 50, 100, and 150 times of brushing to obtain the lightness (L^*) values of the sound and the demineralized tooth surfaces. The difference in the average value between toothpaste groups at each treatment period was analyzed by one-way ANOVA. The difference in the L^* average value according to the number of the brushing was analyzed by repeated measure ANOVA. Results: All toothpastes in the seven groups contained abrasive agents and had different ingredients for each product. Compared to before brushing, the L^* value changed significantly in all toothpaste groups after brushing 50 times (p<0.05). This was common in both the sound and demineralized teeth surfaces. Demineralized teeth had significantly lower L^* values at all brushing times than that in sound teeth (p<0.05). Conclusion: The effect of whitening teeth was different for each toothpaste. Demineralized teeth were more likely to cause coloration than sound teeth, and the coloration was not removed well.

• 대한소아치과학회지
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• 제51권2호
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• pp.165-175
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• 2024

This study aimed to investigate the effects of blood contamination on the Vickers hardness and the surface morphology of premixed MTA and compare them with the effects on conventional MTA. The Vickers microhardness of Endocem MTA Premixed Regular (EP) and ProRoot MTA (PM) was assessed after immersion in fetal bovine serum (FBS) and saline. Stem cells from human exfoliated deciduous teeth (SHED) were seeded on MTA after immersion in FBS, saline, and deionized water (DW). Cell adhesion patterns and surface morphology were visualized via scanning electron microscopy (SEM). The surface microhardness of EP and PM in FBS was lower than in saline. However, short-term exposure of PM to FBS did not reduce the microhardness compared to saline. Angular crystals formed in water, while rounded crystals with more air voids appeared in FBS. Favorable SHED attachment occurred in all groups. Overall, the surface hardness of EP and PM decreased after FBS exposure, although PM was less influenced. We suggest minimizing the amount of bleeding when using MTA clinically; nevertheless, PM remains an option with more expected blood contamination than EP. In summary, exposure to FBS decreased mechanical performance but allowed cell adhesion for both MTAs, with PM being more resistant to these changes.

• 대한소아치과학회지
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• 제41권3호
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• pp.233-240
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• 2014

어린이용 영양제의 우식 유발능에 관해 알아보기 위하여 국내에서 시판 중인 건강기능식품 어린이용 영양제 4종에 대한 생체외 연구를 시행하였다. 어린이용 영양제 4종을 실험군으로, 10% 자당을 양성 대조군, 인공 타액을 음성 대조군으로 하였다. 실험군 및 대조군의 pH, 완충능, 산생성능, 우치 법랑질 침식능을 검사하였다. 실험군 4종의 pH 모두 탈회 임계 pH인 5.5보다 낮았다. 완충능은 Hama Vitamin Pharm이 가장 크고, Smart Chewable Vitamin A가 가장 작았다. 4개의 실험군은 음성 대조군보다 유의하게 높은 산생성능을 보였다(p < 0.05). 우치 법랑질 침식능 검사 결과, 4종의 실험군과 양성 대조군에서 표면미세경도가 유의하게 감소하였다(p < 0.05). 표면미세경도 감소율은 실험군 중에서 Hama Vitamin Pharm이 유의하게 높았고, Hikid Plus는 유의하게 낮았다(p < 0.05).

• 치위생과학회지
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• 제21권2호
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• pp.96-103
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• 2021

Background: We aimed to investigate the effect of Citrous limon extract (CLE) on oxidative stress-induced cytotoxicity and nitric oxide (NO) generation and the tooth bleaching effect of CLE as a substitute for hydrogen peroxide (H₂O₂) and determine the feasibility and application of CLE as a safe and effective natural tooth bleaching agent. Methods: The protective effect of CLE on H₂O₂-induced cytotoxicity in Raw264.7 macrophages was investigated by the MTT assay. The inhibitory effect of CLE on the generation of H₂O₂-induced NO was confirmed by the NO assay, and the changes in inducible nitric oxide synthase (iNOS) protein expression were confirmed by western blotting. Stained bovine teeth were treated with/without 15% and/or 35% CLE and H₂O₂, 15% sodium bicarbonate (NaHCO₃) for 3 hours, and were irradiated with/without bleaching light (BL) for 15 minutes. The color change of the treated bovine tooth surface was measured using a colorimeter. Results: The viability of Raw264.7 cells treated with each concentration of CLE and 500 μM H₂O₂ significantly increased as CLE increased, and NO generation and iNOS protein expression were significantly reduced in cells treated with 300 ㎍ CLE+/500 μM H₂O₂+ and 300 ㎍ CLE+/500 μM H₂O₂+/150 ㎍ NaHCO₃+. The bleaching effect of 35% CLE+ was higher than that of 15% CLE+ and 15% NaHCO₃+, and the effect was similar to that of 15% H₂O₂+. The 35% CLE+/15% NaHCO₃+ showed the greatest bleaching effect and was higher than that of the groups irradiated with the BL. The greatest bleaching effect was observed with 35% CLE+/15% NaHCO₃+, followed by 35% H₂O₂+/BL+. Conclusion: CLE inhibited oxidative stress-induced cytotoxicity and NO generation in Raw264.7 cells and, could replace H₂O₂, which causes side effects and risks in teeth breaching treatment. It showed greatest teeth bleaching effect when combined with NaHCO₃. CLE is an effective and safe natural tooth bleaching substitute.

• 치위생과학회지
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• 제23권1호
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• pp.20-28
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• 2023

Background: This study aimed to determine the effect of ramen sauce on tooth tone changes over time, after selecting three different ramen colors from the ramens sold in the market, and applying the sauce to bovine teeth. Methods: Healthy bovine teeth were selected, and cutting discs were used to produce 60 specimens (5× 5× 3 mm), with 15 specimens distributed per county. Three types of ramen (buldak, chacharoni black bean sauce, and ottogi curry noodle) were used as the experimental group, and water was used as the negative control group. Tooth tone measurement was performed using a spectrophotometer (CM-700d) to measure the color before and after 1 (3 h 44 min), 2 (7 h 28 min), 3 (11 h 12 min), and 4 weeks (14 h 56 min). Analysis of the color tone change was performed using Statistical Package for the Social Sciences version 28. Results: In the experimental group, there was a significant color tone change before and after immersion. L^* indicated the largest change in black bean sauce ramen, a^* indicated buldak ramen, and b^* indicated the largest change in curry ramen. The amount of color change (∆E^*) was the largest in curry ramen, followed by buldak and black bean sauce ramens. The results of the post-hoc analysis showed significant differences between all groups except buldak and black bean sauce ramens. Conclusion: All three types of ramen revealed significant color change before and after immersion, and curry ramen showed the largest amount of color change among them.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.95-102
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• 2009

Purpose: The aim of this report is to investigate the efficacy of anorganic bovine bone xenograft(Bio-$Oss^{(R)}$) at maxillary sinus floor augmentation. Materials and methods: Two male patients who missed maxillary posterior teeth were included. They were performed maxillary sinus floor augmentation using anorganic bovine bone xenograft(Bio-$Oss^{(R)}$). After 10 or 13 months, the regenerated tissues were harvested using trephine drills with 2 or 4mm diameter and non-decalcified specimens were made. The specimens were examined histologically and histomorphometrically to investigate graft resorption and new bone formation. Results: Newly formed bone was in contact with Bio-$Oss^{(R)}$ particles directly without any gap between the bone and the particles. The proportions of newly formed bone were $23.4{\sim}25.3%$ in patient 1(Pt.1) and 28.8% in patient 2(Pt.2). And the proportions of remained Bio-$Oss^{(R)}$ were $29.7{\sim}30.2%$ in Pt.1 and 29.2% in Pt.2. The fixtures installed at augmented area showed good stability and the augmented bone height was maintained well. Conclusion: Anorganic bovine bone xenograft(Bio-$Oss^{(R)}$) has high osteoconductivity and helps new bone formation, so that it can be used in maxillary sinus floor augmentation.

• 대한치과의사협회지
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• 제56권4호
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• pp.208-216
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• 2018

Patients with malocclusion may present with preexisting mucogingival problems susceptible to attachment loss during or after orthodontic treatment. Lower anterior teeth especially show a high prevalence of gingival recession following orthodontic treatment. This case report demonstrates hard tissue augmentation of labially thin or deficient alveolar bone (dehiscences and fenestrations) to prevent attachment loss during or after orthodontic treatment. Three patients presented clinically prominent root surfaces and dehiscences and fenestrations on cone-beam computed tomography (CBCT) in lower anterior teeth. Labial hard tissue augmentation of lower anterior teeth was performed with deproteinized bovine bone mineral and collagen membrane. Six months later, hard tissue augmentation reduced root prominence and created a greater volume of hard tissue on lower anterior area in clinical and radiographic findings. Hard tissue augmentation using xenograft could prevent attachment loss associated with orthodontic treatment and maintain stability of healthy periodontium.