Nd-YAG 레이저 조사와 불소도포가 법랑질의 내산성 변화에 미치는 영향에 관한 실험적 연구

모현철,양규호 전남대학교 치과대학 1991 전남치대논문집 Vol.3 No.1

The purpose of this study was to examine the combined effects of a pulse d Nd-YAG laser and acidulated phosphate fluoride(APF) on acid resistance of bovine tooth enamel. The materials were 54 freshly extracted bovine permanent teeth with intact smooth enamel surfaces and sectioned sagitally and horizontally for 214 experimental specimens. To determine the most effective energy density of laser in increasing acid resistance of tooth enamel, the authors divided 70 specimens into 7 groups including unlased control and 6 experimental groups. Among them, 60 specimens for 6 experimental groups were exposed to a pulsed Nd-YAG laser under conditions ranged from 10 to 60 J/㎠ with an increment of 10J/㎠. Total 70 specimens for unlased control and 6 xperimental groups were etched with 1ml of 0.5N HCIO_4 for 30sec at room temperature and then the amount of dissolved calcium in the acidic solution was determined with an atomic absorption spectrophotometer. Scanning electron microscopic(SEM) observations were also made to examine the enamel surfaces of the lased teeth with 14 specimens for unlased control and 6 experimental groups. To survey the combined effects of a pulsed Nd-YAG laser and APF on acid resistance of enamel, the authors divided 90 specimens into 9 groups according to treatment method(APF only, APF after lasing, lasing after APF) and fluoride application time(4min, 60min, 24hr). After determination of the most effective laser-APF combination method on acid resistance by the amount of dissolved calcium in the acidic solution, the rest 40 specimens for SEM were divided into 20 groups according to treatment method(untreated control, APF only, the most effective laser + APF method) and etching time(non-etching, 15, 30, 60, 90 sec). And then, the surfaces of each treated specimens were also observed with SEM. The results were as follows : 1. The acid resistance of enamel surface was increased significantly compared to untreated control at the laser energy density of 40J/㎠ and 50J/㎠, but more increased at 50J/㎠ without statistical difference between both groups. Laser energy density of 40J/㎠ produced the almost uniform fusion of the lased enamel surface, while that of 50J/㎠ produced the fusion of enamel surface and fine cracks of a mosaic pattern. 2. In the groups etched for 90 sec, the enamel surface of lasing(50J/㎠) only group showed its prism structure as clearly as in the control, APF only group. But a part of enamel structure was still resistant to acid in the group treated with APF after lasing. 3. Longer incubation with APF did bring about an increase in acid resistance but there was no significant increase in acid resistance from 4min treated group with the same treatment method except the group treated APF for 24hr after lasing(50J/㎠). 4. The group of APF application after lasing(50J/㎠) caused a remarkable increase in acid resistance of the enamel, while the group of lasing after APF application showed a lesser effect similar to either APF only or lasing only group.

Nd-YAG 레이저 조사와 불소도포가 법당질의 내산성 변화에 미치는 영향에 관한 실험적 연구

양규호,모현철 大韓小兒齒科學會 1992 大韓小兒齒科學會誌 Vol.19 No.1

The purpose of this study was to examine the combined effects of a pulsed Nd-YAG laser and acidulated phosphate fluoried(APF) on acid resistance of bovine tooth enamel. The materials were 54 freshly extracted bovine permanent teeth with intact smooth enamel surfaces and sectioned sagitally and horizontally for 214 experimental specimens. To determine the most effective energy density of laser in increasing acid resistance of tooth enamel, the author divided 70 specimens into 7 groups including unlased control and 6 experimental groups. Among them, 60 specimens for 6 experimental groups were exposed to a pulsed Nd-YAG laser under conditions raged from 10 to 60J/㎠ with an increment of 10J/㎠. Total 70 specimens for unlased control and 6 experimental groups were etched with 1ml of 0.5N HCIO₄ for 30sec at room temperature and then the amount of dissolved calcium in the acidic solution was measured with an atomic absorption specrophotometer. Scanning electron microscopic(SEM) observations were also made to examine the enamel surfaces of the lased teeth with 14 specimens for unlased control and 6 experimental groups. To survey the combined effects of a pulsed Nd-YAG laser and APF on acid resistance of enamel, the author divided 90 specimens into 9 groups according to treatment method(APF, only, APF after lasing, lasing after APF) and fluoride application time(4min, 60min, 24hr). After determination of the most effective laser-APF combination method on acid resistance by the amount of dissolved calcium in the acidic solution, the rest 40 specimens for SEM were divided into 20 groups according to treatment method(untreated control, APF only, the then, the most effective laser+APF method ) and etching time (non-etching, 15, 30, 60, 90 sec). And then, thd surfaces of each treated specimens were also observed with SEM. The results were as follows: 1. The acid resistance of enamel surface increased significantly compared to untreated control at the laser energy density of 40J/㎠ and 50J/㎠, but more increased at 50J/㎠ without statistical difference between both groups. Laser energy density of 40J/㎠ produced the almost uniform fusion of the lased enamel surface and 50J/㎠ produced the fusion of enamel surface while that of 50J/㎠ produced the fusion of enamel surface and fine cracks of a mosaic pattern. 2. In the groups etched for 902 sec, the surface of lasing(50J/㎠) only group showed its prism structure as in the control, APF only group. But a part of ena,el structure was still resistant to acid in the group treated with APF after lasing. 3. Longer incubation with APF did bring about as increase in acid resistance but there was no significant increase in acid resistance from 4min treated group with the same treatment method except the group treated APF for 24hr after lasing(50J/㎠) 4. The group of APF application after lasing(50J/㎠) caused a remarkable increase in acid resistance of the enamel, while group of lasing after APF application showed a lesser effect similar to either APF only or lasing only group.

선천성 치아기형을 동반한 Chromosome 9의 Pericentric Inversion에 관한 증례

양규호,모현철 大韓小兒齒科學會 1990 大韓小兒齒科學會誌 Vol.17 No.2

The authors observed a patient with pericentric inversion of chromosome 9 whose karyotype was 46, XY, inv (9) (p13 q13). The patient, 22-month-old male, was referred to the Department of Pedodontics of Chonnam National University with the chief complaint of severe dental caries of maxillary anterior teeth. The purpose of this case report is to observe physical & dental abnormalities in a child with pericentric inversion of chromosome 9 with a brief review of the literatures. The following results were obtained: 1. Pediatric clinical findings were mental retardation, low level of intelligence, verbal and motor retardation, general hypotonia, flat nasal bridge, oblique palpebral fissures, telecanthus, prominent epicanthal fold, low set/ malformed ears, and congenital heart disease. 2. Pedodontic perioral findings were constantly open mouth, relative marcroglossia, ankyloglossia, narrow palate, thumb sucking, anterior openbite, anterior gingival swelling and redness, fusion of upper/lower left and right primary incisors, congenital missing of upper permanents left and right lateral incisors, and nursing bottle caries, but there was no delayed eruption of primary teeth. 3. In family study, We could consider genetic and familial tendency because of elder brother whose clinical findings were psychomotor retardation, autism and cleft lip etc. But we failed to examine the chromosomes of patients and elder brother due to insistent refusal of the mother.

Effects of epigallocatechin gallate on CoCl_(2)-induced apoptosis in PC12 cells

Yang, Kyu-Ho,Mo, Hyun-Chul,Choi, Nam-Ki,Kim, Seon-Mi,Kim,Won-Jae 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride (CoCl_(2)) has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG). a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by CoCl_(2) and effects of EGCG on CoCl_(2)-induced apoptosis in PC12 cells. Administration of CoCl_(2) decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with 100 µM EGCG for 30 min before PC12 cells were exposed to 150 µM CoCl_(2), being resulted in the cell viability and DNA fragmentation being rescued. CoCl_(2) caused morphologic changes such as cell swelling and condensed nuclei, whereas EGCG attenuated morphologic changes by CoCl_(2). EGCG suppressed the apoptotic peak and a loss of Δψ_(m) induced by CoCl_(2). CoCl_(2) decreased Bcl-2 expression but Bax expression was not changed in CoCl_(2)-treated cells. EGCG attenuated the Bcl-2 underexpression by CoCl_(2). CoCl_(2) augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity, a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by CoCl_(2). NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated CoCl_(2)-induced apoptosis in consistent with those of EGCG. These results suggest, that CoCl_(2) induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against CoCl_(2)-induced apoptosis in PC12 cells. 신경세포자멸사는 저산소 및 허혈환경에서 일어나며 이러한 세포죽은 reactive oxidant species (ROS) 생성을 동반함이 알려져있다. 그러나, 저산소 및 허혈환경에서 일어나는 세포자멸사의 기전 및 그 치료방법은 아직 정립되어 있지 않다. CoCl_(2)는 ROS를 생성하는 등 저산소환경과 유사한 조건을 초래하는 것으로 알려져 있다. Epigallocatechin gallate (EGCG)는 녹차의 polyphenol 성분으로서 세포성장과 죽음에 다양한 약리학적 효과를 나타냄이 알려져 있다. 본 연구는 PC12 세포에서 CoCl_(2)에 의한 세포자멸사기전을 밝히고 이에 미치는 EGCG의 효과를 조사하는데 목적이 있다. Cell viability는 MTT 측정으로 조사되었고, DNA fragmentation은 DNA laddering으로 조사되었다. Bcl-2와 Bax발현 정도는 RT-PCR로, caspase-3와 -9의 활성은 spectrophotometer, caspase-8의 활성은 flow cytometry에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 western blot으로, 분해된 DNA 양과 미토콘드리아 세포막전위 (Δψ_(m))는 FACScan으로 조사되었다. CoCl_(2)투여로 PC12 세포수는 용량 및 시간 의존형태로 감소하였고, genomic DNA fragmentation이 발생하였다. CoCl_(2)투여로 야기된 cell viability의 감소와 DNA fragmentation은 EGCG 전처치에 의해 억제되었다. CoCl_(2)은 세포용적팽창과 condensed nuclei 같은 형태적 변화를 일으켰으며, apoptotic peak, Δψ_(m)감소 및 cytochrome c 유리를 야기하였다. EGCG는 CoCl_(2)에 의한 세포형태변화, apoptotic peak, Δψ_(m)소실 및 cytochrome c 유리를 억제시켰다. CoCl_(2)는 Bcl-2 발현을 감소시켰지만, Bax 발현에는 영향을 미치지 않았다. EGCG는 CoCl_(2)에 의해 야기된 Bcl-2 발현 감소를 억제시켰다. CoCl_(2)는 caspase-3, -8, 그리고 -9의 활성을 증가시켰으며, EGCG는 CoCl_(2)에 의한 세포자멸사를 억제시켰다. 본 실험결과는 PC12 세포에서 CoCl_(2)가 미토콘드리아 의존 및 death receptor의존 기전으로 세포자멸사를 일으키며, EGCG는 세포자멸사기전을 억세지킴으로 신경보호기능을 가짐을 시사하였다.

혼합치열기 아동의 교합양상에 관한 역학적 연구

양규호,모현철,신강호 전남대학교 치과대학 1991 전남치대논문집 Vol.36 No.1

인터넷 망에서의 정책기반 트래픽 경로제어 기법을 이용한 맞춤형 공지 서비스 제공방안 연구

이세희(Sehui Lee),모현철(Hyunchul Mo),호경중(Kyungjoong Ho),이병희(ByongHee Lee),전윤철(Yunchul Jun) 대한전자공학회 2008 대한전자공학회 학술대회 Vol.2008 No.12