• 한국생물환경조절학회:학술대회논문집
• /
• 한국생물환경조절학회 2001년도 봄 학술발표논문집
• /
• pp.45-50
• /
• 2001

Stem firmness and flowering response of cut lily as influenced by medium composition (Control: Upland soil, Pt: Peatmoss, Pe: Perlite, Ve: Vermiculite, Rrh: Rotted rice-hull, RPt: Russian Peatmoss) were studied. For 'Casa Blanca', plant height and length of flower stalk increased when bulbs were planted in Pt:Rrh:Ve(1:1:1, v/v), and dried leaves of lower part plants decreased by RPt:Pe:Rrh(1:1:1, v/v). In case of 'Marco Polo' plant height and length of flower stalk increased with Pt:Rrh(1:1, v/v) as compared to other treatment, number of leaves and dried leaves increased when bulbs were planted in RPt:Pe:Rrh(1:1:1, v/v) as compared to control. Flowering of 'Casa Blanca' was promoted in Pt:Pe:Ve(1:1:1, v/v) and 'Marco Polo' was accelerated in Pt:Rrh:Ve(1:1:1, v/v). Flower length of 'Casa Blanca' was increased by RPt:Pe:Rrh(1 :1 :1, v/v) as compared with control and 'Marco Polo' was increased when bulbs planted to Pt:Rrh(1 :1, v/v). Flower-bud blasting of two cultivars was increased with Pt as compared with other treatment. Stem firmness of 'Casa Blanca' was increased by Pt:Pe:Ve (1:1 :1, v/v), and especially, stem firmness of upper part plants was increased by Pt:Rrh(1 :1, v/v) in 'Marco Polo' as compared to control plants. but generally, stem firmness of 'Casa Blanca' was not influenced with all cultural media as compared to control.

• 산업경영시스템학회지
• /
• 제44권3호
• /
• pp.39-49
• /
• 2021

The Korean Air-Force aircraft maintenance depot paints the exterior of various aircraft, including high-tech fighters. Aircraft exterior painting is a maintenance process for long-term life management by preventing damage to the aircraft surface due to corrosion. The de-painting process is essential to ensure the quality of aircraft exterior paints. However, because the Korean Air-Force's de-painting process is currently done with sanding or Plastic Media Blasting (PMB) method, it is exposed to harmful dust and harmful compounds and consumes a lot of manpower. This study compares the de-painting process currently applied by the ROK Air-Force and the more improved process of the US Air Force, and performs economic analysis for the introduction of advanced equipment. It aims to provide information that can determine the optimal time to introduce new facilities through Cost-Volume-Profit (CVP) analysis. As a result of the analysis, it was confirmed that the sanding method had the most economical efficiency up to 2 units per year, the PMB method from 3 to 21 units, and the laser method from 22 units or more. In addition, in a situation where the amount of de-painting work is expected to increase significantly due to the increase in fighters in future, BEP analysis was conducted on the expansion of the existing PMB method and the introduction of a new laser method. As a result of the analysis, it was confirmed that it is more economical to introduce the laser method when the amount of work exceeds the PMB work capacity(18 units per year). The paper would helpful to improve the productivity and quality of the Korean Air Force Aircraft maintenance depot through timely changes of facilities in the workplace in preparation for expansion.

• 구강회복응용과학지
• /
• 제27권4호
• /
• pp.393-403
• /
• 2011

이 연구의 목적은 임상적으로 사용되는 RBM과 산부식 임플란트의 3년 생존율을 비교, 분석하기 위한 것이다. 총 152개의 RBM 임플란트를 식립하였고, 이 중 1개의 임플란트에서 실패가 발생하였는데, 원인은 식립체의 파절이었다. 또한 총 152개의 산부식 표면 임플란트를 식립하였는데, 이 중 7개의 임플란트에서 실패를 하였으며, 원인으로는 과열, 감염, 초기고정 불량 등이었다. RBM 임플란트의 생존율은 99.34%, 산부식 임플란트의 생존율은 95.39%로 두 가지 임플란트 모두 양호한 생존율을 보였으나, RBM 임플란트에서 다소 높은 생존율을 나타내었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제34권3호
• /
• pp.325-340
• /
• 2008

The purpose of this study was to evaluate the artificial dental plaque by Streptococcus mutans on 4 different implant surfaces. In this study, the specimens were divided into 4 groups according to implant surface treatment. Uncoated implant group(n=5) which has an uncoated, smooth surfaced implant(Osstem, Korea), SLA implant group(n=5) which has an sandblasted large grit and acid-etched surface implant(Bicon, USA). Oxidized implant group(n=5) which has an oxidized surfaced implant (Osstem, Korea), and RBM implant group(n=5) which has resorbable blasting media(RBM) surfaced implant(Osstem, Korea). Acquired pellicle by human saliva and dental plaque by Streptococcus mutans were made on each implant surface. To analyze the plaque condition on implants surfaces, cell count and optical density were taken as a microbiologic method, and SEM(Scanning Electronic Microscope) findings was also taken for evaluation of surface condition. The following results were obtained. 1. Cell counting results of artificial dental plaque were Uncoated group($658.0{\pm}102.0$), RBM group($878.0{\pm}170.0$), SLA group ($946.0{\pm}42.0$), Oxidized group($992.0{\pm}40.0$), and there was difference between Oxidized group and Uncoated implant group(p<0.05). In case of modified cell counting results by v/w% were RBM group($197.8{\pm}45.2$), Oxidized group($207.04{\pm}8.34$), Uncoated group($261.6{\pm}40.6$), SLA group($315.4{\pm}14.0$), and there was difference between RBM group and SLA group(p<0.05). 2. Optical density results of artificial dental plaque after ultrasonic treatment was that there was difference among groups, and optical density of RBM group was higher than that of Uncoated group(p<0.05). In case of modified optical density results by v/w%, there was difference among groups, and the modified optical density of Uncoated group and SLA group was higher than those of Oxidized group and RBM group(P>0.05). 3. SEM findings of artificial dental plaque on the surfaces of implant as follows; there were artificial dental plaque on the surfaces of all test implants. Streptococcus mutans and by-product were observed at 10,000 times magnified condition on all test implants. Adhesion area of artificial dental plaque was about 1/2 of total surface after 24 hours incubate at $37^{\circ}C$. These results showed that there were differences among implant surfaces on the growth of Streptococcus mutans, and bacteria and by-product were covered about 1/2 area of total implant surfaces at 24 hours incubate at $37^{\circ}C$.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제34권3호
• /
• pp.285-292
• /
• 2008

Purpose: The present study was performed to evaluate the effect of surface treatment of the cervical area of implant on bone regeneration in fresh extraction socket following implant installation. Materials and methods: The four minipigs, 18 months old and 30 kg weighted, were used. Four premolars of the left side of both the mandible and maxilla were extracted. ${\phi}$3.3 mm and 11.5 mm long US II plus implants (Osstem Implant co., Korea) with resorbable blasting media (RBM) treated surface and US II implants (Osstem Implant co., Korea) with machined surface at the top and RBM surface at lower portion were installed in the socket. Stability of the implant was measured with $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden). After 2 months of healing, the procedures and measurement of implant stability were repeated in the right side by same method of left side. At four months after first experiment, the animals were sacrificed after measurement of stability of all implants, and biopsies were obtained. Results: Well healed soft tissue and no mobility of the implants were observed in both groups. Histologically satisfactory osseointegration of implants was observed with RBM surface, and no foreign body reaction as well as inflammatory infiltration around implant were found. Furthermore, substantial bone formation and high degree of osseointegration were exhibited at the marginal defects around the cervical area of US II plus implants. However, healing of US II implants was characterized by the incomplete bone substitution and the presence of the connective tissue zone between the implant and newly formed bone. The distance between the implant platform (P) and the most coronal level of bone-to-implant contact (B) after 2 months of healing was $2.66{\pm}0.11$ mm at US II implants group and $1.80{\pm}0.13$mm at US II plus implant group. The P-B distance after 4 months of healing was $2.29{\pm}0.13$mm at US II implants group and $1.25{\pm}0.10$mm at US II plus implants group. The difference between both groups regarding the length of P-B distance was statistically significant(p<0.05). Concerning the resonance frequency analysis (RFA) value, the stability of US II plus implants group showed relatively higher RFA value than US II implants group. Conclusion: The current results suggest that implants with rough surface at the cervical area have an advantage in process of bone regeneration on defect around implant placed in a fresh extraction socket.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제31권3호
• /
• pp.237-242
• /
• 2009

Implant-supported fixed and removable prostheses provide a proper treatment modality with reliable success. The SS $II^{(R)}$ Implants is a one-stage nonsubmerged threaded titanium implants with Resorbable Blasting Media (RBM) surface developed by Osstem company (Busan, Korea) in October of 2002. This study is to evaluate the survival rate of the SS $II^{(R)}$ Implants for 4 years using radiographic parameters and to review the retrieved implants by the cytotoxicity tests. Since September 2003, 439 SS $II^{(R)}$ implants had been used for 173 patients at Ewha Womans University Medical Center in Korea. Patients consisted of 91 females (52.6 %) and 82 males (47.4 %). The patients' mean age was $42\;{\pm}16$ years, ranging from 21 to 83 years. The follow-up period ranged from 9 to 46 months (mean F/U $24.2\;{\pm}\;10.2$ months). The results are as follows; 1. Of 439 implants, 17 implants were removed and 4-year cumulative survival rate was 96.1%. 2. 82.3% of 17 failed implants were founded during healing phase, and 94.1% of failed fixtures were removed within 5 months after implantation. 3. Crestal bone around the implants was resorbed to 1 mm in 89.0%, to 1 - 2 mm loss of the marginal bone in 8.3%, and the bone loss over 2 mm was occurred in 2.7%. 4. Microscopic examination of the retrieved implants disclosed Grade 0 cytotoxicity in 4 and Grade 1 cytotoxicity in 2 of 6 groups divided according to LOT numbers. Inhibition rate with optical density was acceptable as low as ISO standard.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제29권4호
• /
• pp.301-308
• /
• 2007

Purpose: This study was performed to compare and evaluate the effect of recipient site depths and diameters of the drills on the primary stability of implant in pig's ribs. Materials and methods: An intact pig's rib larger than 8 mm in width and 20 mm in height; RBM(resorbable blasting media) surface blasted ${\phi}3.75mm$ and 8.0 mm long USII Osstem Implants (Osstem Co., Korea) were used. To measure the primary stability, $Periotest^{(R)}$ (Simens AG, Germany) and $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden) were used. They were divided into 6 groups according to its recipient site formation method: D3H3, D3H5, D3H7, D3.3H3, D3.3H5, D3.3H7. Each group had, as indicated, 10 implants placed, and total 60 implants were used. The mean value was obtained by 4-time measurements each on mesial, distal, buccal, and lingual side perpendicular to the long axis of the implant using $Periotest^{(R)}$ and $Osstell^{TM}$. For statistical analysis one-way ANOVA was used to compare the mean value of each group, and the correlation between placement depths and the primary stability, and that of measuring instruments was analyzed using SPSS 12.0. Results: The primary stability of the implants increased as the placement depths increased (p<0.05), and showed a proportional relationship (p<0.01). The primary stability increased when the diameter of the recipient site was smaller than that of the implant but with no statistical significance. There was a strong correlation between $Osstell^{TM}$ and $Periotest^{(R)}$ (p<0.01). Conclusion: These results suggest that increasing the placement depth of implants enhances the primary stability of implant.

• 구강회복응용과학지
• /
• 제23권4호
• /
• pp.327-336
• /
• 2007

Fixture의 안정도를 평가하는 장비인 Osstell Mentor와 기존 Osstell과의 비교 시험 및 측정환경에 따른 노이즈 발생 시험 결과를 통해 다음과 같은 결과를 얻었다. 1. US II Fixture와 SS II Fixture의 ISQ 값을 측정한 1차 검증에서는 Osstell과 Osstell Mentor의 ISQ 값 경향의 차이가 크게 나타나지 않음을 확인하였다. 2. SS II Fixture를 얕게 매식한 것과 정상적인 매식한 것의 ISQ 값 비교를 한 2차 검증에서는, Osstell과 Osstell Mentor 모두 매식 깊이에 따른 동일한 경향의 결과를 보였다. 3. 3차 검증에서는 골질별로 Osstell과 Osstell Mentor의 ISQ 값이 일정한 경향을 보이는 것을 확인하였고, 특히 Osstell Mentor 장비는 Osstell 장비보다 사용함에 있어서 편리성이 뛰어나다고 판단된다. 또한 ISQ 값을 100% 신뢰하기는 어렵지만 Osstell Mentor를 임상 및 실험에 적용하는데 있어서는 문제가 없을 것으로 판단된다. 4. 측정환경에 따라 전자파를 발생시키는 환경이 존재하면 노이즈가 발생할 수 있으나, 실제 측정결과 휴대폰이 작동 중인 환경을 제외하고는 노이즈가 발생하지 않았다. 실제 치과 내에서의 사용에서도 노이즈는 발생하지 않음을 확인하였다. 5. 비교적 안전하게 장치를 장착 및 탈착 할 수 있어 측정과정에 의해 발생되는 임플란트와 주위골에 대한 잠재적 위험도가 낮고 측정위치에 따른 오차가 적어 임상적으로 불리한 상황과 다양한 환경에서의 임플란트 안정성 측정이 가능해 임상적 활용도가 높다고 판단된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권4호
• /
• pp.291-299
• /
• 2005

Objectives : It is well known that cigarette smoking is harzardous to the osseointegration of dental implant, due to the impaired wound healing accompanied by reduced alveolar bone density. The aim of this study is to evaluate the influence of cigarette smoke on the implant osseointegration by the time factor consideration. Materials and methods : Twenty-four male Spraque-Dawley rats (8 weeks, weighting 200 to 250g) were used in this study. In the experimental group, 13 rats were exposed to cigarette smoke, 8 minutes per day during 6 weeks, and 12 rats in the control group were not exposed at any time. RBM (Resorbed blasting media) surfaced implant (diameter 3.3mm, length 5.0mm, AVANA Co., Korea) was placed in the right femur of each rat. Each implant with surrounding bone was prepared with microtome (cutting band 0.2mm$^{(R)}$, EXAKT Co., Germany) after 1 day, 2, 4, 8 and 12 weeks and stained with toluidine blue (1%). Another clinical investigation of each implant was also done at each evaluation time. Results : Clinical investigation around implant fixture showed that there were no significant differences between the control and experimental group. Microscopic observation around implant fixture showed that there were significant differences between the control and experimental group at the initial stage after implant fixture installation. Experimental group showed a decreased bone to implant contact within 4 weeks compared to control group, but showed similar characteristics after 4 weeks. Conclusion : Smoking inhalation effect on the dental implant showed the impaired wound healing by vasoconstriction and decreased intramedullary blood flow at initial stage of osseointegration. This experimental results can be clinically useful to the implant surgery of smoking patients.

• Journal of Periodontal and Implant Science
• /
• 제37권2호
• /
• pp.209-221
• /
• 2007

Recently, immediately after losing teeth. implant placement has been greatly attempted. Implant can help restoration of tooth functions within short time. This study was an attempt to examine the extent of osseointergation when the implants will be placed immediately after teeth extraction using domestic implant systems. Implants were inserted in beagle dogs and evaluated the clinical, radiological, histological and histomorphometric assay at 6 weeks and 12 weeks. For experimental materals, $STAGE-1^{(R)}$($4.1{\times}8mm$, Lifecore, USA), $SS-III^{(R)}$($4.0{\times}8mm$, OSSTEM, Korea) and $IFI^{(R)}$($4.0{\times}8mm$, Dio, Korea) implants treated with RBM were placed. All the placed site showed normal results without fail and inflammation clinically and radiologically. As a result of measurement by periotest, it showed $-2\;{\sim}\;-5$ and stable status comprehensively. There was no statistically significant difference among implants(p<0.05). Bone tissue adjacent to implant showed increased marrow tissue at 6 weeks. Nevertheless, osteogenic structure was not observed remarkably. In a 12 weeks opinion, bone tissue composed of osseointegration along implant interface showed significantly decreased marrow tissue containing central vessels unlike a 6 weeks opinion and matured compact bone whose osteogenic structure is well formed. BIC were 42.4%, 32.0% and 34.9%, respectively in 6 weeks and there was no statistically significant difference among group(p<0.05). In 12 weeks, BIC were 58.8%, 61.9% and 57.5%. respectively and there was no statistically significant difference among groups(p<0.05). It is considered that all 3 implant systems are suitable for immediate implant placement.