• Journal of dental hygiene science
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• v.21 no.4
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• pp.243-250
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• 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
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• v.33 no.6
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• pp.560-569
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• 2008

Microorganism survived in the root canal after root canal cleaning and shaping procedure is a main cause of root canal treatment failure. There are several mechanisms for the bacteria to survive in the root canal after chemomechanical preparation and root canal irrigation. Bacteria organized as biofilm has been suggested as an etiology of persistent periapical lesion. Recent studies were focus on removal of Enterococcus faecalis biofilm due to the report that the persistence of this bacteria after root canal treatment may be associated with its ability to form biofilm. Several investigations demonstrated that current root canal treatment protocol including use of NaOCl, EDTA and Chlorhexidine as irrigants is quite effective in eliminating E. faecalis biofilm. However, this microorganism still can survive in inaccessible areas of root canal system and evade host immune response, suppress immune activity and produce biofilm. Up to date, there is no possible clinical method to completely get rid of bacteria from the root canal. Once the root canal treatment failure occurred, and conventional treatment incorporating current therapeutic protocol has failed, periapical surgery or extraction should be considered rather than prolong the in effected retreatment procedure.

• Journal of Life Science
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• v.21 no.8
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• pp.1120-1126
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• 2011

Rosa multiflora thunberg belonging to Rosaceae is widely distributed in East Asia including Korea and Japan, and has been reported to have tormentic acid and rosamultin. To develop a new natural anti-inflammatory agent for cosmetics, we investigated the inhibitory effects of inflammation in Rosa multiflora root (R. multiflora root). The biological activity and anti-inflammatory effects were investigated by water, ethanol, methanol and acetone extracts of R. multiflora root. The measurements of polyphenol content from R. multiflora root were highest in water and acetone extracts, at 57.48 ${\pm}$ 0.88 mg/g and 67.05 ${\pm}$ 0.56 mg/g, respectively. The result of DPPH, ABTS and superoxide anion radical scavenging effects showed over 50% efficacy at 50 ${\mu}g/ml$ in ethanol, methanol and acetone extracts. Hyaluronidase inhibition effect showed over 60% efficacy at 500 ${\mu}g/ml$ in ethanol, methanol, and acetone extracts. Nitric oxide radical inhibition effect of R. multiflora root ethanol extracts showed over 30% efficacy at 500 ${\mu}g/ml$. We investigated the effect of R. multiflora root extracts on nitric oxide (NO) production of inducible nitric oxide synthase (iNOS) in LPS-induced RAW 264.7 macrophage cells. The result showed that R. multiflora root extracts have an inhibitory effect on NO production and iNOS expression and also can be used as an anti-inflammatory agent. These antioxidant and anti-inflammatory effects of R. multiflora root show applicant potential application as a functional cosmetic material.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.49-56
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• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.183-189
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• 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
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• v.22 no.2
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• pp.761-768
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• 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
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• 2004.08a
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• pp.1371-1374
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• 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
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• v.38 no.4
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• pp.204-209
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• 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.

• The Korean Journal of Applied Statistics
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• v.23 no.1
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• pp.73-79
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• 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
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• v.1 no.1
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• pp.11-17
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• 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.