Journal of the korean academy of Pediatric Dentistry
/
v.30
no.2
/
pp.320-325
/
2003
The purpose of study was to investigate the effect of carbon dioxide laser on demineralization inhibition and rehardening of primary tooth enamel according to its power and irradiation time. 2mm diameter circle on the primary enamel surface was irradiated by defocused $10.6{\mu}m$ superpulse carbon dioxide laser at 6 Watt 2 seconds or at 3 Watt 8 seconds, before or after demineralization by Coca-Cola for 24 hours. Enamel surface change was measured by the Diagnodent. The results were analyzed with the former study results of 3 Watt 4 seconds and 6 Watt and 4 seconds. Diagnodent scores increased significantly after demineralization of irradiated enamel at 6W 2s or 3W 8s (P<0.05). Among the four groups, only 6W 4s group showed obvious demineralization inhibition effect. Diagnodent scores reduced significantly after 6W 2s or 3W 8s irradiation of demineralized enamel(P<0.05). Among the four groups, 6W 4s showed nearly complete rehardening effect, and the other groups showed partial effect. Tooth discoloration only occurred at 6W 4s. It seemed that caries inhibition and tooth discoloration depend on laser power more than total irradiation energy.
Kim, Nam Hyuk;Kim, Seong Oh;Song, Je Seon;Lee, Jae Ho;Son, Heung Kyu;Choi, Byung Jai;Choi, Hyung Jun
Journal of the korean academy of Pediatric Dentistry
/
v.40
no.3
/
pp.159-167
/
2013
The aim of this study was to evaluate changes in demineralization resistance and bonding strength of light cured glass ionomer after the addition of nano hydroxyapatite in various ratios. Fuji II LC GIC (GC Co., Japan) was used as the control group and also as a base material for experimental group. HA was mixed into the RMGIC at various ratio to create a HA-LC GIC mixture, preparing six experimental groups, i.e. 5%, 10%, 15%, 20%, 25%, 30% HA-LC GIC. According to the results, the bonding strength increased due to the addition of HA, showing the maximum value at the 15% nano HA group (p < 0.05). Under CLSM observation after 4 days of demineralization, the HA groups were more resistant to demineralization compared to the control group. No significant difference was observed between HA groups. In analysis through SEM, the HA groups showed attachment of granular materials and decreased demineralized tooth surfaces under influence of HA particles.
The purpose of this study was to compare the shaping time of two shaping methods and the leakage of three different obturation techniques. Ninty three canaled human molar teeth were used, which were randomly divided into two groups of forty teeth each and ten control teeth. After working length determination, the one group was prepared crown-down technique using rotary root canal instruments of GT rotary files .12/20, .10/20, .08/20 and .06/20 taper(Maillefer Instrument SA. Switzerland). The other group was instrumented with Gates Glidden burs(#1, #2, and #3) to coronal preparation and GT rotary files .08/20 and .06/30 taper to apical preparation. Shaping time was measured. After root canals were instrumented, they were divided to three subgroups and obturated as follows : Subgroup 1, obturated with single cone method Subgroup 2, obturated with lateral condensation : Subgroup 3, obturated with continuous wave technique. Three subgroups were obturated using non-standardized gutta-percha cone(Diadent, Korea, .06 or .08 taper) and AH-26(Dentsply DeTrey, Germany) as a root canal cement. Ten unobturated teeth served as positive and negative controls. After immersion in 2% methylene blue solution for 1 month, the teeth were washed during 24h. The teeth were demineralized in 10% nitric acid and dehydrated by immersion in 80, 90 and 100% ethyl alcohol. The teeth were finally cleared and stored in 100% methylsalicylate, and apical dye penetration was evaluated under stereomicroscope(Leica M420, LC, U.S.A)at $\times$8.75 magnification. Liner measurement of dye penetration was assessed with the use of digitalized image analysing system (analySIS, GmbH, Germany) The data were analysed statistically using independent T-test and Two-way ANOVA and Tukey test. The result were as follows 1. In canal prepared with GT$^{TM}$ rotary file, shaphing time taked more than the group of using Gates Glidden drill to coronal preparation without statistical significance (p>0.05) 2. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files showed significantly more apical leakage than those of lateral condensation and continuous wave technique regardless of shaping method (p<0.05). 3 The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed significantly more apical leakage than those of continuous wave technique regardless of shaping method (p<0.05). 4. Regardless of shaping method, The group of continuous wave obturation showed less apical leakage than those of lateral condensation without statistical significance (p>0.05). 5. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed more apical leakage than the group of lateral condensation using same shaping method with-out statistical significance (p>0.05).
Ha, Hyun-Jung;Kim, Soon-Hee;Yoon, Sun-Jung;Park, Sang-Wook;So, Jung-Won;Kim, Moon-Suk;Rhee, John-M.;Khang, Gil-Son;Lee, Hai-Bang
Polymer(Korea)
/
v.32
no.1
/
pp.26-30
/
2008
This study was designed to investigate the effect of hybridization of synthetic/natural materials for annulus fibrosus (AF) tissue regeneration in vitro and in vivo. The synthetic/natural hybrid scaffolds were prepared using PLGA (poly (lactic-co-glycolic) acid), SIS (small intestinal submucosa) and DBP (demineralized bone particles). PLGA, PLGA/SIS(20%), PLGA/DBP(20%) and PLGA/SIS (10%)/DBP (10%) scaffold were manufactured by solvent casting/salt leaching method. Compressive strength was measured. Rabbit AF cells were isolated, cultured and seeded into experimental groups. Hydroxyproline production and DNA quantity of AP cells on each scaffold was measured at 2, 4 and 6 weeks after in vitro culture. Cell-scaffold composites were implanted subcutaneously into athymic mice. After 1,4 and 6 weeks postoperatively, specimens were taken and H&E, Safranin-O and type I collagen staining were carried out concerning formation of cartilagenous tissue. In vitro PLGA/SIS scaffold was evaluated for total collagen content (bydroryproline/DNA content) and PLGA scaffold was evaluated for compressive strength.
The purpose of this study was to observe the effect of dentin surface conditioners on the dentin surfaces. Freshly extracted human molars were used in this study. They were stored at $4^{\circ}C$ saline solution before experiment. The crown portions of the teeth were cut in various directions by means of wet diamond point to expose dentin which include transverse, vertical oblique, horizontal and oblique cut to the long axis (Fig. 1). Each tooth was then mounted with self curing acrylic resin in brass ring to expose the flattened dentin surfaces. Final finish was accomplished by grinding the dentin specimens with wet No. 180 and No. 600 grit silicon carbide abrasive paper until a 6.0mm in diameter on a dentin surface was exposed without pulp exposure. The specimens were divided into 9 groups according to the modes of dentin treatment procedure. The following surface treatments were applied on these preparation surfaces; Group 1: unetched (control group) after finish with No. 600 silicon carbide abrasive paper. Group 2: etched with 30% phosphoric acid for 60s Group 3: etched with 10-3 solution for 60s Group 4: Cleaned with 5% NaOCl for 30s Group 5: applied Dentin Adhesit Group 6: cleaned with 5% NaOCl followed by applying the Dentin Adhesit$^{(R)}$ Group 7: applied Photo Bond on the unetched dentin followed by applying the Photo Clearfil Bright Group 8: Etched with 30% phosphoric acid followed by applying Photo Bond and Photo Clearfil Bright Group 9: etched with 10-3 solution followed by applying Photo Bond and Photo Clearfil Bright All the specimens were stored in $37^{\circ}C$ under 50% relative humidity for 24 hours before observations. The specimens in 7, 8, and 9 group, omitting the group 1 to 6, were demineralized in 10% HCl for 10s in order to observe the resin tags. All the specimens in each group were then dried at room temperature. The dried specimens were ion coated with Eiko ion coater (Eiko-engineering Co.), and observed in Hitachi S-430 Scanning electron microscope (Hitachi, Co. Tokyo) at 15KV. The following results were obtained as follows; 1. The smear layers were still remained in group 1,2,4,5, and 6. 2. There is no effect of 5% NaOCl and 30% phosphoric acid on the changes of dentin morphology 3. The dentin treated with 10-3 solution, indicating the tubules opened when the smear layer and the dental plug dissolved. 4. In case of applying the bonding agents the resin tag was not formed at the deep area of dentinal tubules, but in case of applying the Dentin Adhesit$^{(R)}$ that was not.
Journal of the korean academy of Pediatric Dentistry
/
v.27
no.4
/
pp.564-572
/
2000
We decided among extraction, orthodontic traction and autotransplantation such as direction and position of unerupted tooth, degree of developing root apex, eruption space, being of supernumerary tooth or odontoma or cyst when tooth impacted. Autotransplantation is considered when orthodontic traction is unrealistic or when tooth movement can absorb root of neighbor tooth. The prognosis for successful autotransplantation is dependent on a number of factors such as root development, surgical technique, patient's age, endodontic treatment, time and type of splinting, preservation of periodontal ligament and storage medium. Especially when severe osseous defect is being, bone graft considered for reducing of mobility and for assisting recovery. In all cases, chief complaint is unerupted tooth and various causing factors were supernumerary, odontoma, ectopia and so on. Before autotransplantation, space regaining was done if needed and demineralized freezed dried bone and autogenous bone graft was done when there is severe osseous defect by extraction of supernumerary tooth or odontoma. Splinting was removed after 2-3weeks At 3-4weeks after autotransplantation, endodontic treatment was decided. At follow up check, normal recovery was done and there was no inflammatory or replacement root resorption in periapical radiograph.
The purpose of this study was to evaluate the detection ability of secondary caries using qunatitative light-induce fluorescence-digital (QLF-D) device. Twenty bovine teeth with cavity on surface were demineralized during 21 days for secondary caries lesion of cavity wall. After 21 days, cavity was filled using composite resin and cut the specimen in half with disc. Fluorescence loss of lesion on surface by time flow, cross sectional lesion, and lesion of filled or unfilled surface were analyzed using analysis software. ${\Delta}F$ (value of fluorescence loss) of the lesion on surface assessed by the QLF-D increased significantly over time up to 21 days. And ${\Delta}F$ value of lesion of filled surface is significantly lower than that of unfilled surface (p<0.001). ${\Delta}F$ of filled surface is 1.31 times of cross section lesion. The correlation of between ${\Delta}F$ of filled surface lesion and ${\Delta}F$ of cross section lesion was showed low agreement (0.026) and correlation of between ${\Delta}F$ of unfilled surface lesion and ${\Delta}F$ of cross section lesion was showed high agreement (0.613). In conclusion, secondary caries can be detected on surface using QLF-D. However, interference of fluorescence of filling material is the points to be especially considered for exact analysis of secondary caries lesion.
This study was aimed to investigate the effects of indomethancin on physiologic root resorption and to examine the dental pulp and tissue changes around the resorbing teeth 13-14 week old six mongrel dogs were divided into 3 groups, two experimental groups administered indomethacin 2mg/kg/day and 8mg/kg/day orally two times a day for 14 days respectively. and control group administered a placebo The deciduous incisors showing root resorption were selected. fixed for 24 hrs in $10\%$ formalin solution. demineralized in $10\%$ EDTA solution. Invested in paraffin and sectioned in $5{\mu}m$ thick sections. The preparations were stained with H&E staining and Masson's trichrome staining and examined under the light microscope Observation revealed that deciduous root resorbing tissue resembles inflammatory tissue and accompanies bore remodelling. The dental pulp was formal except the area near root resorption. well organized columnar odontoblasts layer under the predentin, anud the odontoblasts near root resorption were cuboidal or flat cells in the disrupted layer under the predentin. Indomethacin administered group showed a partial decrease in the number of odontoclasts and nucleus But there was no sign of pulp change by indomethacin. These results suggest that indomethacin inhibits recruitment of odontoclasts partially and that of osteoclasts more. and so when it is administered for long periods deciduous root resorption can be delayed and eruption of the successor can be delayed for a short period.
Kim, Jae-Gon;Kweon, Seon-Ja;Yun, Hyun-Du;An, Soo-Hyeon;Baik, Byeong-Ju
Journal of the korean academy of Pediatric Dentistry
/
v.25
no.1
/
pp.209-224
/
1998
The purpose of this study was to compare the amount of calcium fluoride deposited on the enamel and dentin surface and to obtain information on the morphological change and crystallographic details of mineral deposition after 12,000ppm APF application in vitro. The bovine enamel and dentin blocks were randomly assigned to eight groups according to artificial caries lesion formation and difference of fluoride application time. The fluoride concentration and morphological characteristics on the treated enamel and dentin surface were investigated by using fluoride quantitative analysis and SEM. The powdered enamel and dentin of the intact bovine incisors were prepared for the X-ray diffraction analysis. The following results were obtained. 1. The amounts of KOH-soluble fluoride on the carious enamel and dentin surface after 24h APF application were higher than after only 5min APF application(p<0.05), but in the case of the sound enamel and dentin surface were similar after 5min and 24h application (P>0.05). The fluoride content was highly increased in the carious dentin as compared with sound dentin after APF application(P<0.05). 2. The carious enamel surface after APF application, the demineralized enamel surface were recovered a more dense enamel surface and precipitation of crystal was observed a distintive surface layer of spherical globules of about 1 m diameter. In the case of the fluorided carious dentin surface, precipitation of calcium fluoride-like material was deposited both inside the dentinal tubules as well as in the intertubular regions. 3. The crystallographic structure of powdered enamel and dentin after 24h APF application had large crystallities of apatite and CaF2 diffraction peaks in the enamel as compared with dentin. The diffraction data collected from the 27.50-29.50(2) angular range of the powdered enamel, the (105) apatite, (225) apatite and (111) CaF2 peaks of the enamel crystallities were detected after 24h APF application.
Journal of the korean academy of Pediatric Dentistry
/
v.32
no.3
/
pp.454-460
/
2005
The purpose of study was to observe the effect of calcium and citric acid on the dental erosion of human premolar enamel. Enamel specimens were demineralized in 0.1%, 0.3%, 0.5%, or 1.0% citric acid solutions with 0.05%, 0.1%, or 0.2% calcium for 5, 15, 30, and 60 minutes, and then the surface microhardness of the enamel was measured. The hardness decreased as the concentration of citric acid and the demineralization time increased. Hardness after 5 minutes was 76~90% in case of no calcium and the inhibition of dental erosion by calcium addition was 2??15%. Hardness after 15 minutes was 65~84% in case of no calcium and the inhibition of dental erosion by calcium addition was 3~17%. Hardness after 30 minutes was 53~72% in case of no calcium and the inhibition of dental erosion by calcium addition was 6~22%. Hardness after 60 minutes was 43~66% in case of no calcium and the inhibition of dental erosion by calcium addition was 7~19%. The inhibition was the highest in 1.0% citric acid and 0.2% calcium. In 0.1% citric acid the inhibition increased as the demineralization time increased, but in 0.3% to 1.0% citric acid the inhibition was most high at 30 minutes and decreased a little at 60 minutes. These results suggest that calcium has a inhibitory effect on the citric acid induced dental erosion.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.