• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
• /
• pp.69-70
• /
• 2017

In Korea, silicone type sealant is widely used for construction site. Before the silicone type, urethane type is one of the main type sealants. However, the weathering property is less than the silicone type, the urethane type is replace by the silicone one. Still the urethane type is used for the inside of the buildings for the perimeter of the window. The silicone type sealants are better in weathering property than those of the urethane type sealants. Except the weathering property urethane type sealant has its own advantage like movement property, low cost and so forth. There are many research results for the outdoor weathering of the sealants, but in Korea there are no results for the outdoor weathering for construction sealants. This research is focused on the outdoor weathering of the urethane sealants, how to measure the degradation, and compare the products which used in Korea. The outdoor weathering test is usually time consuming, thus we designed specialized device for accelerating the result.

• 대한소아치과학회지
• /
• 제21권2호
• /
• pp.429-438
• /
• 1994

Since the introduction of pit and fissure sealants in the early 1970's, many studies have been published amply documenting the efficacy of these materials as caries-preventive agents. However, the acceptance of the technique by dentist has been questionable. This survey was investigated the attitudes toward and use of pit and fissure sealants by dentist in Chonbuk area. The results were as follows: 1. Utilization of pit and fissure sealants is very high. Only 15% of dentists never use pit and fissure sealants, whereas 85% generally use pit and fissure sealants. 2. Most dentists reported that their knowledge of pit and fissure sealants was gained through dental schools education. 3. Concern about difficult to sell' to patient, poor retention of pit and fissure sealants and unsubstantiated by research were given as the main reasons why pit and fissure sealants was not used. 4. Patient demands and various educate program were given as important factors that would lead to increase use of pit and fissure sealants.

• 한국치위생학회지
• /
• 제22권5호
• /
• pp.347-354
• /
• 2022

Objectives: This study aimed to evaluate the relationship between pit and fissure sealants of the molars, and caries prevalence and experience to assess the effect of sealants on caries prevention. Methods: Data from 16,119 people were extracted from the seventh Korean national health and nutrition examination survey, which was conducted from 2016 to 2018. Demographic, socioeconomic, oral health-related behavioral, and oral examination survey data were collected as independent variables. SAS statistics for complex samples and multiple logistic regression analysis (Windows ver. 9.4) was used for the statistical analyses. Results: Caries prevalence and experience were significantly associated with age, sex, daily toothbrushing frequency, interdental cleaning, and having molar sealant. Multiple logistic regression analysis revealed a significant association between having molar sealants and the caries prevalence and experience among participants under 30 years of age after adjusting socio-economic variables and toothbrushing-related factors. Conclusions: This study confirmed the effect of molar sealants on caries prevention in Korea. Our results support that the application of molar sealants in children, adolescents, and young individuals is effective in preventing caries.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제7권4호
• /
• pp.149-162
• /
• 2007

Field and accelerated tests are performed to assess the service life of construction sealants. Mathematical degradation models for tensile strength and elongation, that are the two major performance characteristics of sealants, are derived from the test results. Accelerated degradation test methods for assessing service life of construction sealants are developed based on the degrading performance and a numerical example is provided.

• 대한치과의사협회지
• /
• 제49권1호
• /
• pp.22-32
• /
• 2011

This paper reviewed the following subheadings and a few selected references in each section were discussed: ${\cdot}$ Sealant placed over caries; is it possible? Initial caries which is not sticky during proving is possible to be placed with sealants. ${\cdot}$ Prophylaxis of fissure; which method is most effective? Mechanical preparation with fissurotomy or resin polishing bur is one of the most effective method to clean the pit and fissure. ${\cdot}$ Glassionomer cement as a sealant; GIC, wheather it released fluoride or not, cannot be as cost-effective as resin-based sealants. ${\cdot}$ Sealant products; Color(white vs opaque), fluoride(containing vs not), filler component(filled vs non-filled) do not influenced the quality and retention of sealants. ${\cdot}$ Use of intermediate bonding agent to improve retention; Intermediate bonding may increase the retention rate of sealants ${\cdot}$ Penetration method of sealants; Several methods including waiting before light curing are recommended.

• Elastomers and Composites
• /
• 제34권3호
• /
• pp.199-211
• /
• 1999

본 연구에서는 PVC졸 실란트에 요구되는 접착성 개선제에 대한 연구의 일환으로 에폭시가 2개(epoxy A)인 것과 4개인 것(epoxy B)을 각각 첨가하였을 때 PVC졸 실란트의 제반물성에 미치는 영향을 연구하였다. PVC졸은 디옥틸프탈레이트(DOP)로 PVC를 가소화시켜 제조된 것이다. 에폭시 수지 A의 경우는 에폭시 수지 함량이 증가할수록 PVC졸 실란트의 점도가 감소하였고, 첨가제 $CaCO_3$가 첨가된 에폭시 PVC졸 실란트의 점도는 에폭시 수지 종류에 관계없이 $CaCO_3$ 함량이 증가할수록 점도가 증가했다. $45^{\circ}C$ 열 수조상에서 점도 변화는 에폭시 수지 종류 또는 함량에 관계없이 점도가 감소하였는데 이는 에폭시가 PVC졸 실란트에 안정제의 역할을 한 것으로 판단되었고, $CaCO_3$가 함유된 경우는 그 함량이 증가할수록 점도가 증가한 것은 충진효과로 판단되었다. 에폭시가 첨가된 PVC졸 실란트의 열적 안정성은 다소 개선되었다. 인장 강도는 에폭시 수지 A의 함량이 낮은 경우는 인장 강도 및 신율이 증가하고, 높은 함량에서는 오히려 감소했다. 에폭시 수지 B의 경우는 에폭시 함량이 증가할수록 인장 강도와 신율은 증가하는 현상이 보였다. 충진제 함량이 많을수록 충진제 함량이 적은 PVC졸보다도 인장 강도는 낮은 현상을 보였다. 전기적 특성에서는 tan ${\delta}$의 값이 0.1정도($0.1{\pm}0.04$)이고 비유전율 ${\epsilon}_r$ 값은 0.5정도($0.5{\pm}0.04$)이므로 좋은 절연체로 판단되었다.

• 치위생과학회지
• /
• 제15권6호
• /
• pp.768-774
• /
• 2015

본 연구는 만 6세부터 18세까지를 대상으로, 2007~2013년도 국민건강영양조사 원시자료를 이용하여 치면열구전색 수혜량을 파악하고, 수혜량에 미치는 요인을 분석하고자 10,416명을 대상으로 조사하였다. 분석에는 STATA 11.0을 이용하였으며, 분석한 결과 다음과 같은 결론을 얻었다. 7년간의 치면열구전색 수혜량은 평균은 1.12개로 나타났으며, 치면열구전색의 급여화가 시행되기 전인 2007~2009년 11월까지는 평균 0.93개, 급여화 실시 후에는 1.24개로 증가하였다. 일반적 특성에 따른 치면열구전색 수혜량은 소득수준이 높을수록, 건강보험과 민간보험에 가입되어 있을수록, 1일 칫솔질 횟수가 많을수록 높게 조사되었다. 하지만 성별과 연령의 경우는 통계적으로 유의한 차이를 보이지 않았다. 치면열구전색 수혜량에 영향을 미치는 요인으로는 치면열구전색 급여화 여부, 소득수준, 건강보험 유형 및 민간보험 가입 여부, 1일 칫솔질 횟수로 나타났다. 이상의 결과를 종합해보면 치면열구전색 급여화가 시행된 2009년 12월을 기준으로 2010년에 치면열구전색 수혜량 증가를 보이긴 하나, 그 2011년부터는 다시 감소하는 경향을 보이고 있다. 치면열구전색 수혜량을 늘리기 위해서는 치면열구전색 급여화에 대한 홍보를 강화하고, 저소득층에 대한 지원확대 및 사회경제적 수준에 따른 본인부담금 차등화 등의 방안이 논의되어야 할 것으로 생각된다. 또한 치면열구전색 급여화를 시작으로 추후에는 예방처치에 대한 급여화 확대방안에 대해 다각적인 검토가 필요할 것이다.

• Restorative Dentistry and Endodontics
• /
• 제42권1호
• /
• pp.39-47
• /
• 2017

Objectives: Although the coating of surface sealants to dental composite resin may potentially reduce bacterial adhesion, there seems to be little information regarding this issue. This preliminary in vitro study investigated the adhesion of Streptococcus mutans (S. mutans) on the dental composite resins coated with three commercial surface sealants. Materials and Methods: Composite resin (Filtek Z250) discs (8 mm in diameter, 1 mm in thickness) were fabricated in a mold covered with a Mylar strip (control). In group PoGo, the surfaces were polished with PoGo. In groups PS, OG, and FP, the surfaces polished with PoGo were coated with the corresponding surface sealants (PermaSeal, PS; OptiGuard, OG; Fortify Plus, FP). The surfaces of the materials and S. mutans cells were characterized by various methods. S. mutans adhesion to the surfaces was quantitatively evaluated using flow cytometry (n = 9). Results: Group OG achieved the lowest water contact angle among all groups tested (p < 0.001). The cell surface of S. mutans tested showed hydrophobic characteristics. Group PoGo exhibited the greatest bacterial adhesion among all groups tested (p < 0.001). The sealant-coated groups showed statistically similar (groups PS and FP, p > 0.05) or significantly lower (group OG, p < 0.001) bacterial adhesion when compared with the control group. Conclusions: The application of the surface sealants significantly reduced S. mutans adhesion to the composite resin polished with the PoGo.

• Bulletin of the Korean Chemical Society
• /
• 제21권11호
• /
• pp.1115-1118
• /
• 2000

Specimens were cured by using a 1 mm (thickness) ${\times}$5 mm (diameter) teflon mold, and were immersed in artificial saliva and in 75% ethanol for 1, 7, 14, 21 and 28 days in order to quantify and to identify toxic components and to determine any degra dation byproducts of Bis-GMA that might be released from five commercially available resin-based dental sealants. In artificial saliva, the only released component was triethylene glycol dimethacylate (TEGDMA). In 75% ethanol, TEGDMA, 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy) phenyl]propane (Bis-GMA) and urethane dimethacrylate (UDMA) were released highly at the initial stage, indicating that the amount of component released is not linearly correlated with the immersion time. The amount of released TEGDMA was found to be much higher in 75% ethanol than in artificial saliva. Importantly, bisphenol-A (BPA) was detected from all the uncured sealants tested, suggesting that all the sealants tested contain BPA as a contaminant.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
• /
• pp.53-58
• /
• 2002

Electrical insulation and mechanical properties of the plasma sprayed oxide ceramic coatings were studied before and after the sealing treatment of the ceramic coatings. Plasma sprayed A1$_2$O$_3$-TiO$_2$ coating as the reference coating was sealed using three commercial sealants based on polymer. Penetration depth of the sealants to the ceramic coating was evaluated directly from the optical microscope using a fluorescent dye. It is estimated that the penetration depth of the sealants to the ceramic coating is from 0.2 to 0.5 mm depending on the sealants used. The preliminary test results with a DC puncture tester imply that the dielectric breakdown voltage mechanism of plasma sprayed ceramic coatings has been determined to be a corona mechanism. Dielectric breakdown voltage of the as-sprayed and as-ground samples have shown a linear trend with regard to the thickness showing an average dielectric strength of 20 kV/mm for the thickness scale studied. It is also shown that grinding the coating before sealing and adding fluorescent dye do not agent the penetration depth of sealants. All of the microhardness, two-body abrasive wear resistance, bond strength, and surface roughness of the ceramic coating after the sealing treatment are improved. The extent of improvement is different from the sealants used. However, three-point bending stress of the ceramic coating after the sealing treatment is decreased. This is attributed to the reduced micro-crack toughening effect since the cracks propagate easily through the lamellar of the coating without crack deflection and/or branching after the sealing treatment.