복합레진 접착력의 레이저 영향에 관한 연구

윤현두,백남규,백병주 全北大學校 齒醫學硏究所 1991 전북치대논문집 Vol.9 No.1

The purpose of this study was investigating the shear bond strength between posterior composite resin and enamel surface of the permanent premolar. The enamels of sound permanent premolars extracted for orthodontic therapy were used for experiment. They were classified into 6 groups at random ; 2 Clearfil self-cured resin groups and 2 P-50 light-cured resin groups and 2 Clearfil light-cured resin groups which have lased group and unlased group each other. Laser impacts on each experimental groups were made at energy density of Pulsed Nd : YAG laser with 40 J/㎠. Then the decalcified patterns of enamel by 37% phosphoric acid and resin tags of each group were investigated with scanning electron microscope and adhesive shear bond strength was measured on the each decalcified enamel surface after adhesion of light-cured and self-cured resins. The obtained results were as follows. 1. There were significant increase in shear bond strength of Clearfil light-cured resin groups and Cleafil self-cured resin groups in contrast to P-50 light-cured resin groups at significant level α=0.05 in unlased condition(P<0.05). 2. There were not significant difference statistically between the groups but increased order in shear bond strength was ; Clearfil self-cured resin groups, Clearfil light-cured resin groups, P-50 light-cured resin groups in lased condition(P>0.05). 3. In case of P-50 light-cured resin groups, there was significant increase of shear bond strength at significant level α=0.01 after laser irradiation(P<0.01). In case of Clearfil light-cured resin and Clearfil self-cured resin groups, there was increase of shear bond strength but not significant statistically at significant level α=0.05 after laser irradiation(P>0.05). 4. There were significant increase in shear bond strength of Clearfil light-cured resin groups and Clearfil self-cured resin groups in contrast to P-50 light-cured resin groups at significant level α=0.05 in all groups(P<0.05). 5. The sample of high shear bond strength had many resin tags were deep and uniform penetration and the resin tags had many small tags in contrast to the sample of low shear bond strength.

불소농도가 인공우식 범랑질의 재석회화에 미치는 영향

윤현두,백병주,김재곤 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.1

The purpose of this study was to evaluate the remineralized effect of fluoride on artificial carious enamel after topical fluoride application and to certificate the most appropriate fluoride concentration. Artificial demineralized bovine enamel blocks were randomly assigned to four groups, and placed in fluoride, 100, 5,000 and 12,000ppm acidulated phosphate fluoride solution. Sound enamel blocks without artificial carious lesion were used as control group. In this study, the morphological characteristics of treated enamel surface and effect of fluoride concentration on remineralization of artificial carious enamel has been investigated by using scanning electron microscopy, chemical analysis and electron probe microanalysis compared with the effect of various fluoride concentration. The Following results were obtained. 1. The enamel surface treated with 100ppm APF was observed more demineralized surface with lots of holes and loosely bounded a few globules. 5,000ppm APF treatment produced a deposits of numerous spherical globules 0.5∼1㎛ in diameter and distinctive rectangular and cuboidal shaped deposits were formed by 12,000ppm APF treament. 2. Amount of KOH-soluble fluoride on enamel surfaces was increated according to treated fluoride concentration level. In the Ⅳ and Ⅴ group were showed significantly higher than that in the Ⅲ group(p<0.05). 3. After treatment with 5,000 and 12,000ppm APF, a remarkable elevation of the fluoride profile was observed within 30㎛ of the outermost layer and was accompanied simultaneously by a high elevation of the calcium profile. However, specimens treated with 100ppm APF showed only a small elevation of fluoride within whole depth than that in the sound and demineralized enamel specimens. 4. In the Ⅳ and Ⅴ group, Ca/P weight percent ratio were showed higher than that in the Ⅰ, Ⅱ, Ⅲ group in 5 and 15㎛ depth, and fluoride content were showed statistically different than that in the Ⅰ, Ⅱ, Ⅲ group in all depth(p<0.05).

와동내에 조사된 열의 전도양상에 관한 연구

윤현두,허선,김재곤,이두철,백병주 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.3

The purpose if this study was to evaluate temperature change occurred in enamel, dentin and pulp due to the heat from cavity prepration with laser. We made three models had different cavity depth : cavity depth of model Awas 3.52mm, model B was 2.32mm, model C was 1.16mm. We irradiated cavity base with thermal capacity of 30J,100J,300J/㎤s during few seconds and studied the change of temperature in tooth during 10 seconds, and estimated change of thermal capacity by different irradiated site and exposure time. AT 300j/㎤s irradiation for 2 seconds, the temperature of irradiated surface was elevated fast according to irradiated thermal energy during I second, In proportion to continuous exposure time, temperature elevated slowly The surface temperature was 1370℃. After discontinue of thermal irradiation, the heat of irradiated surface was diffused in dentin and pulp and the greatest temperature was made, The greatest temperature was disappeared within 10 seconds The greatest temperature of the inner part of model brought about very severe change by different depth. Temperature in pulp was raised by the greater irradiated energy density and exposure time.

Leukemia 에 대한 증례보고

윤현두,정홍주,백병주 大韓小兒齒科學會 1990 大韓小兒齒科學會誌 Vol.17 No.2

Leukemia is malignant tumor that abnormal cells increase in bone marrow because of abnormality of stem cell and result in anemia, thrombocytopenia, infection & infiltration in other tissue. Leukemia has 5.9% in incidence, following to stomach and uterine cancers and tend to increasing. There are four types of leukemia: acute lymphocytic leukemia, acute myelocytic leukemia, chronic lymphocytic leukemia, chronic myelocytic leukemia. In leukemia, there are swelling of gingiva, bleeding anemia and delayed wound healing in oral cavity. In addition, it is likely to bleeding in ilp, tongue and gingiva, because of decreased platelet. In oral region, candidiasis & ulcer is seen frequently, and secondary infection may occur through the ulcer. Chemotherapeutic agents may result in stomatitis, neuritis, xerostomia in oral mucosa. There is higher incidence in hypodontia, hypoplasia than common case, and there are more tendency in hemorrhage and infection.

매복 반곡된 상악 중절치의 외과적 처치에 관한 증례보고

백병주,윤현두,김미경 大韓小兒齒科學會 1991 大韓小兒齒科學會誌 Vol.18 No.2

The treatment of unerupted tooth are surgical exposure,orthodontic repositioning ,transplantation and extraction. In treating unerupted tooth,it must be considered to position and dilaceration of unerupted tooth,patient age,requirement of patient. Case mentioned here is autotransplantation of unerupted tooth and dilacerated central incisor. For the successful treatment,it is required space of trancsplanted tooth and good oral hygiene before surgery.We escape trauma of periodontal ligament and cementum during surgery.We observe occlusion,inflammation,development of roots after transplantation.

불소 및 레이저가 우치법랑질의 인공우식병소에 미치는 영향

백병주,윤현두,김재곤,주훈 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.3

The purpose of this study was to examine the morphological characteristics and combined effects of fluoride application and laser irradiation on artificial caries-like lesion formation in bovine enamel. Enamel specimens were divided into five experiment group and placed in no-treatment(group C), APF application alone(group F), laser irradiation alone(group L), APF application before laser irradiation (group FL), and APF application after laser irradiation (group LF) on artificial caries-like lesion. Sound enamel was used as a control group. The ultrastructural changes and physical effects of the fluorided and lased enamel has been investigated by using SEM, enamel solubility and microhardness test as well as distributions of calcium, phosphorus and fluoride in internal enamel by using EPMA. The following results were obtained. 1. In the all experiment groups, the amounts of dissolved calcium of enamel surfaces signigicantly decreased according to increasing exposure time of acid solution than control group(P<0.001), Group L showed higher than that group FL and LF in 30 and 60 min(P<0.05). 2. The microhardness values of enamel surface in the control group was highest than that in the other experiment groups. Group F, L, FL and LF were significantly increased than group C(P<0.001). 3. The enamel surface treated with APF produced deposites of numerous small globules and lased enamel showed a cracker-like appearance with microcrack and small pore. Numerous deposits were infiltrated in the fissrued portion of enamel treated with APF after laser irradiation. 4. In the case of APF application alone, the elevation of the fluoride profile can be seen within 5㎛ of the outermost layer and a similar profile observed in the specimen treated with APF before laser irradiation. However, the specimen treated with APF after laser Irradiation showed a large elevation within 10㎛ of the outermost layer of the enamel. 5. The higher Ca/P ratios were observed in 10㎛ depth of lased and fluorided enamel when compared to the sound and carious enamel. The fluoride content decreased rapidly with distance from enamel surface, in the group F, fluoride concentration was significantly higher than that in the group C, L, FL, LF and control group according to increasing enamel depth(P<0.05).

불소적용시 법랑질과 상아질에서 불화칼슘형성의 차이에 관한 실험적 연구

김재곤,권선자,윤현두,안수현,백병주 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.1

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 caruous 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.