• 치위생과학회지
• /
• 제21권4호
• /
• pp.243-250
• /
• 2021

Background: Endodontic sealers or their toxic components may become inflamed and lead to delayed wound healing when in direct contact with periapical tissues over an extended period. Moreover, an overfilled sealer can directly interact with adjacent tissues and may cause immediate necrosis or further resorption. Therefore, the treatment outcome conceivably depends on the endodontic sealer's biocompatibility and osteogenic potential. This study aimed to evaluate the cell viability and osteogenic effects of four different sealers in osteoblastic cells. Methods: AH Plus (resin-based sealer), Pulp Canal Sealer EWT (zinc oxide-eugenol sealer), BioRoot RCS (calcium silicate-based sealer), and Well-Root ST (MTA-based calcium silicate sealer) were mixed strictly according to the manufacturer's instructions, and dilutions of sealer extracts (1/2, 1/5 and 1/10) were determined. Cell viability was measured using the water-soluble tetrazolium-8 (WST-8) assay. Differentiation was assessed by alkaline phosphatase (ALP) activity and mineralized nodule formation by Alizarin Red S staining. Results: The cell viability of the extracts derived from the sealers excluding Well-Root ST was concentration dependent, with sealer extracts having the least viability at a 1/2 dilution. At sealer extract dilution of 1/10, the test groups showed the same survival rate as that control group, with the exception of BioRoot RCS. Among all experimental groups, BioRoot RCS showed the highest cell viability after 48 hours. The ALP activity was significantly higher in a concentration-dependent manner. Furthemore, all four materials promoted ALP activity and mineralized nodule formation compared to the control at 1/10 dilutions. Conclusion: This is the first study to highlight the differences in biological activity of these four materials. These results suggest that the composition of root canal sealers appears to alter the form of biocompatibility and osteoblastic differentiation.

• Restorative Dentistry and Endodontics
• /
• 제33권6호
• /
• pp.560-569
• /
• 2008

본 review 논문의 목적은 통상의 근관치료로 해결되지 않는 persistent periapical lesion의 원인이 되는 주요 세균을 제거하고자 시행한 여러가지 실험을 비교분석하여 과연 (1) Enterococcus faecalis가 근관치료 실패의 주요 원인균인지 (2) 그리고 과연 그렇다면 근관치료에 실패한 증례에서 E. faecalis와 biofilm을 제거할 수 있는 치료 protocol이 있는 것인지를 확인하여 보다 나은 근관치료 성공을 위한 치료 protocol의 확립과 앞으로의 연구방향을 재조명하는 것이다. 지금까지 진행되어온 연구 결과에 대한 객관적인 분석이나 적절한 평가가 이루어지지 않은 가운데 어떤 특정한 연구를 통해 E. faecalis를 제거하는데 유의성있는 효과를 보인다고 알려진 세척액이나 약제를 막연한 기대감을 가지고 실제 임상에 사용하고 있는 실정에서 현재 진료실에서 사용하고 있는 치료 protocol에 대한 검증이 절실한 시점에서 review해 본 결과 현재까지 진행되어 왔던 여러 연구 결과를 통해 확신할 수 있는 것은 치료 protocol에 따라 현재 사용하고 있는 근관세척액이나 근관내 약제만으로도 E. faecalis나 그 biofilm을 대부분 제거할 수 있다는 사실이다. 하지만 이 그 protocol에 따라 근관치료 술식을 충실하게 이행한다 해도 근관치료가 100% 성공한다고 보장할 수는 없다. 물론 세균이 아닌 다른 요소에 의해 근관치료의 실패가 일어난다고도 할 수 있지만 그보다는 결국 체내의 면역반응에 저항하는 세균의 능력에 기인하는 것으로 보인다. 따라서 높은 수준의 치료 성공률을 지속적으로 유지하기 위해서는 위에서 언급된 바와 같은 제대로 된 치료 protocol을 따라 근관치료를 진행하면서 좀더 나은 결과를 얻기 위해 새로운 protocol을 개발하고 정립하는 과정이 계속되어야 한다.

• 생명과학회지
• /
• 제21권8호
• /
• pp.1120-1126
• /
• 2011

찔레나무뿌리를 열수, 에탄올, 메탄올, 아세톤에서 추출하여 항산화 및 항염증 효능효과를 확인하였다. 그 결과 아세톤추출물에서 가장 많은 67.05${\pm}$0.56 mg/g의 폴리페놀 함량을 확인하였으며, SOD 유사활성능을 제외한 DPPH, ABTS, superoxide anion 라디컬소거능 확인 결과 우수한 항산화 효과를 확인하였다. 찔레나무뿌리 추출물의 HAase 저해능을 측정한 결과 에탄올, 메탄올, 아세톤 추출물 500 ${\mu}g/ml$ 에서 60% 이상의 높은 HAase 저해 효과를 확인할 수 있었다. NO 생성량을 확인한 결과, RAW 264.7 cell에서 LPS에 의해 유도된 NO 생성을 농도의존적으로 뚜렷하게 감소시키는 것을 확인하였으며, 에탄올 추출물에서 NO 생성억제 효과가 가장 우수한 것을 확인할 수 있었다. 위의 사실에 기초하여 NO 생성저해의 기전을 알아보기 위하여 iNOS의 발현을 분석한 결과, 에탄올추출물 100 ${\mu}g/ml$에서 40%의 iNOS protein 발현 감소를 확인하였으며, iNOS의 발현억제가 NO생성억제와 유사한 경향을 나타냄으로 NO생성억제는 iNOS의 발현저해를 경유한 것임을 확인할 수 있었다. 이러한 결과들은 찔레나무뿌리 추출물이 항산화 및 항염증 연구의 기초 자료로 활용될 것으로 예상된다. 또한 추후 산업적 응용도 가능함으로 기능성화장품의 가능성을 제시하고 있다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제16권2호
• /
• pp.49-56
• /
• 2008

A preliminary survey on the incidence and intensity of root disease complex (association of Meloidogyne incognita and root rot pathogens) was carried out in the sericultural areas of Karnataka. A total of 280 mulberry gardens were surveyed in 14 districts of Karnataka belonging to different types of soil (red sandy, red loamy and black cotton), farming systems (irrigated and rainfed), varieties (V-1, K-2, Local and S-13) and age of the plants (0-5, 5-10 and 10-15 years). It was observed that the association of M. incognita with Botryodiplodia theobromae and Fusarium solani causes the root disease complex in mulberry. Of the 280 gardens visited, 94 were infested with the disease complex and incidence was recorded as 33.6%. The higher intensity of root disease complex was observed when the root system had more than 100 galls/plant with infection of mixed population of B. theobromae and F. solani in sandy soil under irrigated farming. The 5-10 years old mulberry plantation with V-I variety was found to be most susceptible to root disease complex. Districts like Mysore, Kolar, Mandya, Tumkur, Chitradurga and Bangalore were observed as sensitive areas. Further, the wounds caused by M. incognita in mulberry roots favour the easy entry of root rot pathogens, which increased the severity of the disease very fast.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2009년도 추계 학술논문 발표대회
• /
• pp.183-189
• /
• 2009

In this study, the growth diagnosis of root is analyzed through plant's auxanology point of view, and the inductive root barrier ability of panel type waterproofing method which is designed to deal with it, is confirmed positively through long term(2 years) mock-up test. Moreover, basic ideas for inductive root barrier design in joint is presented through this study. The experiment result for the root barrier of sealed A-type during 24 months, there were no damages found on the waterproofing layer. -urethane sealing material was used to apply for waterproofing of joint- for roots. As the result, it was confirmed that it is possible to maintain the root barrier of method through applying inductive root barrier design such as the installation of decreasing space of bearing power which considers the growth diagnosis of root, even if the root barrier was not secured.

• Restorative Dentistry and Endodontics
• /
• 제22권2호
• /
• pp.761-768
• /
• 1997

Microorganisms and their by-products are considered to be the major causes of pulpal and periapical pathosis. The role of microorganisms in endodotic infection has been studied regarding the prevalence of particular organisms found in root canal and periapical lesions. The aim of this study was to investigate the effect of culture supernatants of several oral microorganims isolated from infected root canals on the viability of cultured cell lines using colorimetirc assay. S. simulans, S. sciuri, E. faecium, S. intermedius, S. mitis, S. sanguis and S. uberis were incubated in Todd-Hewitt broth for 16 hours. 20 and 100ul of filtered bacterial cell culture supernatants were added to MK and Hep-2 cells. Cell viability was measured using MIT colorimetric assay. 20ul and 100u1 of S. sanguis supernatant showed significant cytotoxicity compared to control on MK cells. 100ul of S. sanguis supernatant significantly depressed viability of HEp-2 cells. E. faecium and S. intermedius did not affect the viability of MK and HEp-2 cells.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.1371-1374
• /
• 2004

The control system design of 2-DOF for SISO process by root locus technique is not complicated and efficiently. It can design the control system to have the transient and steady state responses, and do not adjust the gain of process controller later. However, due to control system design for MIMO process, by root locus technique, there is not exact method. This paper is presents the control system design method for Quadruple-Tank Process, by using root locus technique for the structure of 2-DOF control system. The design procedures are first decentralized then using the relative gain array, and finally 2-DOF controller design is applied.

• Restorative Dentistry and Endodontics
• /
• 제38권4호
• /
• pp.204-209
• /
• 2013

Objectives: The objective of this in vitro study was to evaluate and compare the cytotoxicity of four different root canal sealers i.e. Apexit Plus (Ivoclar Vivadent), Endomethasone N (Septodont), AH-26 (Dentsply) and Pulpdent Root Canal Sealer (Pulpdent), on a mouse fibroblast cell line (L929). Materials and Methods: Thirty two discs for each sealer (5 mm in diameter and 2 mm in height) were fabricated in Teflon mould. The sealer extraction was made in cell culture medium (Dulbecco's Modified Eagle's Medium, DMEM) using the ratio 1.25 $cm^2/mL$ between the surface of the sealer samples and the volume of medium in a shaker incubator. Extraction of each sealer was obtained at 24 hr, 7th day, 14th day, and one month of interval. These extracts were incubated with L929 cell line and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay was done. Two-way ANOVA for interaction effects between sealer and time and Post-hoc multiple comparison using Tukey's test across all the 16 different groups were used for statistical analysis. Results: Apexit Plus root canal sealer was significantly less toxic than other sealers (p < 0.05) and showed higher cellular growth than control. Endomethasone N showed mild cytotoxicity. AH-26 showed severe toxicity which became mild after one month while Pulpdent Root Canal Sealer showed severe to moderate toxicity. Conclusions: Apexit Plus was relatively biocompatible sealer as compared to other three sealers which were cytotoxic at their initial stages, however, they became biocompatible with time.

• 응용통계연구
• /
• 제23권1호
• /
• pp.73-79
• /
• 2010

Missing values for unit root processes are imputed by the most recent observations. Treating the imputed observations as if they are complete ones, semiparametric unit root tests are extended to missing value situations. Also, an invariance principle for the partial sum process of the imputed observations is established under some mild conditions, which shows that the extended tests have the same limiting null distributions as those based on complete observations. The proposed tests are illustrated by analyzing an unequally spaced real data set.

• Restorative Dentistry and Endodontics
• /
• 제1권1호
• /
• pp.11-17
• /
• 1975

This study is to determine the penetration of various medicaments such as Howe's ammoniacal silver nitrate and methyleneblue, to root canal dentin within given time (5,10,30 sec.) Followings are the results obtained from this study. 1) The dye stuff is more deeply penetrated according to the time elapsed. 2) According to the increase of age, the penetration ratio is decreased accordingly. 3) The penetration ratio of Howe's ammoniacal silver nitrate is higher than that of methyleneblue. 4) The permeability of the root canal dentin is gradually reduced as access to the apex.