• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권6호
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• pp.413-420
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• 2002

Mercury is one of the most frequently used heavy metal in dental clinic. Mercury poisoning rises up when someone is exposed to mercury chronically. In 1818, Amalgam was used for dental restorative procedure, and after then study about mercury toxicity has begun. Clinical signs of mercury toxicity in oral & maxillofacial area were increases of salivation, metallic taste, swelling and pain of tongue, redness and ulceration of oral mucosa, and increased mobility and loss of teeth. After we injected mercury($HgCl_{2}$) into intraperitoneum of rat, studied about histopathological changes of submandibular gland cell. Experimental group was divided into two groups by amount of mercury. (Group 1 was 0.5mg/Kg of mercury injection, group 2 was 1.0mg/Kg of mercury injection.) 1. After 3days of intraperitoneal injection, black granules were observed at macrophage cell in both group. In group 2, author found hyperchromatism of nucleus, and vacuolization of cellular matrix and nucleus of acinar cell. 2. After 1week of intraperitoneal injection, author found severe vacuolization of nucleus and cellular matrix, and irregular granules around nuclear membrane at mucous cell and serous cell in both group. Vacuolization of nucleus and cellular matrix was seen at duct cell in group 2. 3. After 2weeks of intraperitoneal injection, author could found severe vacuolization of cellular matrix, and sometimes nucleus was positioned in central area of cellular matrix at mucous and serous cell in both group. Vacuolization of nucleus and cellular matrix was found at vascular endothelial cell in group 2. 4. After 4weeks of intraperitoneal injection, destruction and distortion of gland cells were distinct. Vacuolization and destruction of nucleus and cellular matrix was found at duct cell in group 2. After intraperitoneal injection of mercury, we found equanimity of mercury and destruction of cellular matrix at serous cell, mucous cell, and duct cell of submandibular gland. So, we thought that metallic taste of mercury poisoning patient would be due to excretion of saliva containing mercury.

• 치과방사선
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• 제12권1호
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• pp.105-113
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• 1982

Because of the development of rampant caries, osteomyelitis and osteoradionecrosis that occur after radiation therapy of oral cancers, extraction of teeth at or near the malignant lesion has been done in the past. Few, however, have studied the radiation effect on the healing of extraction wounds. This study is concerned with the effect of Co-60 irradiation on the healing process of extraction wounds in rats. Fifty six, male, Spraque-Dawley rats are used. The right first molar of the mandible is extracted from all animals. They are divided into three experimental groups of 14 each and a control group of 14. Three experimental groups are irradiated respectively with 200 rad, 400 rad and 600 rad and a pair of rats in each group are killed on days 1, 3, 5, 7, 14, 21 and 28 after irradiation. Two animals from the control group are killed on the day when the experimental rats are killed. The irradiated hemimandibles are fixed in 10% neutral formalin, decalcified in 5% trichloroacetic acid, embedded in paraffin and sectioned. The sections are stained in hematoxylin and eosin, van Gieson, Masson's trichrome or silver nitrate. Results show that in general radiation effects on healing extraction wounds are dose dependent; i.e., the higher is the dose, the greater is the histologic changes observed: 1. Irradiation tends to retard blood clot organization and epithelial regeneration. 2. An increase in the number of giant cells and osteoclasts is noted after irradiation. 3. Formation of regenerating connective tissues around and within the extraction site is com- promised, and a clear reduction of primitive mesenchymal type connective cells is noted. 4. The healing process begins along the lateral aspect of the extraction socket in the control, while irregular histologic appearances of the brabecular pattern is present in the experimental rats.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.843-855
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• 1995

Occupational Dentistry was introduced in Korea about 70 years ago. During the colonial period occupied by Japan till 1945, there were few documents about industrial dentistry, furthermore most cases of occupational diseases and accidents might have been concealed intentionally by the colonial government. After being an independent country, several dentists made efforts to set up 'Preventive Dentistry for Workers' performing specific oral health surveys, even though which were stopped by Korean War. In 1960s' and 1970s', some investigations of oral status were carried out intermittently for specific small groups;white-collar workers, mentally retarded person, buddhist monks and crews of ocean liners. At the same time there was important study in Korean history of occupational dentistry, which was 'a comparison of the oral hygiene conditions in the female workers of a spinning factory at intervals of 30 years.' In 1980s', young researchers began to give attention to erosion of the teeth due to sulphuric acid in the acid-related industry and dental caries due to sugar and flour in the sweets industry. After being democratic labor union movement activated in 1987, hidden and suppressed occupational diseases under the military dictatorship were exposed and flushed in the newspapers. It was shocking for all people that 15-year old boy had been dead due to mercury intoxication after 3-month employment in 1988. In 1990s', the activity for studying oral status of workers in their workplaces was launched and 'Occupational Accidents and Diseases in Oral and Maxillofacial Field' was published. And also The Korean Association of Occupationl Dentistry was established. Oral health examination of workers at the time of employment and of workers exposed to 5 special chemicals at the time of routine special health examination was adopted in 1992, and epocally oral health examination was also included in periodic routine examination of workers' health in 1995. So, occupational dentistry in Korea should cope with the changing needs of working environment and the altering scheme of health examination.

• 대한치과교정학회지
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• 제51권5호
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• pp.304-312
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• 2021

Objective: This study aimed to compare the amount of tooth movement after multiple horizontal (MH) and single vertical (SV) micro-osteoperforations (MOPs), and evaluate the histological changes after orthodontic force application in rabbits. Methods: The mandibles of 24 white rabbits were subjected to two experimental interventions: MH and SV MOPs. Defect volume of the MOPs between the two groups was kept similar. A force of 100 cN was applied via a coil spring between the incisor teeth and the first premolars. The amount of tooth movement was measured. Differences in the amount of tooth movement and bone variables at three time points and between the two groups were evaluated using repeated-measures analysis of variance. Results: The first premolar showed a mesial movement of 1.47 mm in the MH group and 1.84 mm in the SV group, which was significantly different at Week 3 (p < 0.05). No significant difference was observed in bone volume and bone fraction between the groups. Tartrate-resistant acidic phosphatase-positive cell count was also significantly greater at Week 3 than at Week 1 in both the SV and MH groups. Conclusions: The amount of tooth movement showed significant differences between Weeks 1 and 3 in the SV and MH MOP groups, but showed no differences between the two groups. Therefore, SV MOP could be considered an effective tool for enhancing tooth movement, especially for molar distalization, uprighting, and protraction to an edentulous area.

• 대한한방소아과학회지
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• 제37권1호
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• pp.15-44
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• 2023

Objectives The purpose of this study is to analyze the types of childhood simple obesity and suggest clinical symptoms, treatment principles, and traditional Chinese medicine (TCM) treatments for each type. Methods All kinds of literature published by the China National Knowledge Infrastructure (CNKI) up to August 20, 2022 were analyzed. We extracted information about types of childhood simple obesity, relevant clinical symptoms, treatment principles and TCM treatments. Results 25 studies were included. Spleen deficiency with dampness obstruction, gastrointestinal dampness-heat, internal excess of phlegm-dampness were the most reported. Spleen deficiency with dampness obstruction has symptoms of powerless, heavy limbs, pale tongue, teeth-marked tongue, sunken and slippery pulse. As a treatment, herbal medicine (HM) like modified Banggihwanggitang and acupoint like Joksamri were mainly reported. Gastrointestinal dampness-heat has symptoms of thirst, constipation, edacity, rapid hungering, heavy limbs, red tongue, slippery and rapid pulse. HM like Modified Xiehuangsan to clear heat was mainly reported. Internal excess of phlegm-dampness has symptoms of heavy limbs, lack of strength, tongue with white slimy fur, slippery pulse. Modified Ijintang to dry dampness to resolve phlegm was mainly reported. Conclusions This study analyzed types of pattern, clinical symptoms, treatment principles, and TCM treatments of childhood simple obesity. Based on this study, it is necessary to derive a standardized dialectical information that reflects the domestic situation.

• 한국식생활문화학회지
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• 제23권4호
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• pp.438-447
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• 2008

"Gyuhapchongseo" was published in 1809, and introduced the cooking method of the noble class in the late Joseon dynasty. The characteristics of the side dishes in "Gyuhapchongseo" are as follows. Firstly, red pepper was used as whole red pepper, shredded red pepper, powdered red pepper, or Korean hot pepper paste. Secondly, salt-fermented fish was used in some forms of Kimchi, including Sukbakgi, Dong A Sukbakgi, and Gyochimhae. Thirdly, to retain the juiciness of meat during roasting, meat was spread cold water on the surface, dipped into the washing water of rice or wrapped with wet paper. Fourth, to improve the visual effect of a dish, cooked foods were displayed with various color schemes, panfried foods with two tones (egg white and yellow) of color on each side and the use of radish pigmented with deep red color. On examination of the characteristics of food in "Gyuhapchongseo", I would suggest applicable practices for the present cuisine. The use of gravy produced from the boiling down of fish flesh could raise the nutritive value of Kimchi. In "Gyuhapchongseo", Yak po (semi-dried minced beef) is noted as being good for elderly people with bad teeth. A steamed dish with dog meat in Dong A in "Gyuhapchongseo" is made by hollowing out Dong A and putting a dog in it to cook the dog meat to well done in a fire made with the hulls of rice. This technique could be used to present cuisine for steamed and roasted dishes using food ingredients such as pumpkin, sweet pumpkin, and overripe cucumber.

• Restorative Dentistry and Endodontics
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• 제48권4호
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• pp.33.1-33.12
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• 2023

Objectives: This study aimed to evaluate the bleaching efficacy and hydrogen peroxide permeability in the pulp chamber by the at-home bleaching gel in protocols applied on different dental surfaces. Materials and Methods: Forty premolars were randomly into 4 groups: control group no bleaching, only application on the buccal surface (OB), only application on the lingual surface (OL) and application in buccal and lingual surfaces, simultaneously (BL). At-home bleaching gel (White Class 7.5%) was used for the procedure. The bleaching efficacy was evaluated with a digital spectrophotometer (color change in CIELAB [ΔE_ab] and CIEDE 2000 [ΔE₀₀] systems and Whitening Index for Dentistry [ΔWI_D]). The hydrogen peroxide permeability in the pulp chamber (㎍/mL) was assessed using UV-Vis spectrophotometry and data were analyzed for a 1-way analysis of variance and Tukey's test (α = 0.05). Results: All groups submitted to bleaching procedure showed bleaching efficacy when measured with ΔE_ab and ΔE₀₀ (p > 0.05). Therefore, when analyzed by ΔWI_D, a higher bleaching efficacy were observed for the application on the groups OB and BL (p = 0.00003). Similar hydrogen peroxide permeability was found in the pulp chambers of the teeth undergoing different protocols (p > 0.05). Conclusions: The application of bleaching gel exclusively on the OB is sufficient to achieve bleaching efficacy, when compared to BL. Although the OL protocol demonstrated lower bleaching efficacy based on the ΔWI_D values, it may still be of interest and relevant in certain clinical scenarios based on individual needs, requiring clinical trials to better understand its specificities.

• The Journal of Advanced Prosthodontics
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• 제16권1호
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• pp.57-65
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• 2024

PURPOSE. The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques. MATERIALS AND METHODS. The study included 31 inlays for prosthodontics purposes of 31 patients: 15 based on intraoral digital impressions (DI group); and 16 based on a conventional impression technique (CI group). Inlays included occlusal and a non-occlusal surface. Inlays were milled in ceramic. The inlay-teeth interface was replicated by placing each inlay in its corresponding uncemented clinical preparation and taking interface impressions with silicone material from occlusal and free surfaces. Interface analysis was made using white light confocal microscopy (WLCM) (scanning area: 694 × 510 ㎛²) from the impression samples. The gap size and the inlay overextension were measured from the microscopy topographies. For analytical purposes (i.e., 95-%-confidence intervals calculations and P-value calculations), the procedure REGRESS in SUDAAN was used to account for clustering (i.e., multiple measurements). For p-value calculation, the log transformation of the dependent variables was used to normalize the distributions. RESULTS. Marginal fit values for occlusal and free surfaces were affected by the type of impression. There were no differences between surfaces (occlusal vs. free). Gap obtained for DI group was 164 ± 84 ㎛ and that for CI group was 209 ± 104 ㎛, and there were statistical differences between them (p = .041). Mean overextension values were 60 ± 59 ㎛ for DI group and 67 ± 73 ㎛ for CI group, and there were no differences between then (p = .553). CONCLUSION. Digital impression achieved inlays with higher clinical marginal fit and performed better than the conventional silicone materials.

• 치위생과학회지
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• 제13권2호
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• pp.203-212
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• 2013

한국 땃쥐속 우수리땃쥐 Crocidura lasiura와 작은땃쥐 C. suaveolens, 뒤쥐속 뒤쥐 Sorex caecutiens의 치아형태와 법랑질 표면의 함유물을 EDX를 이용하여 정성 분석하였다. 우수리땃쥐와 작은땃쥐의 경우, 치식은 I3/1 C1/1 P1/1 M3/3=28이었고, 상악 제1대구치와 제2대구치는 5개의 교두들로 만들어진 균형이 맞지 않는 W형을 가지고 있었고, 상악 제3 대구치는 상악 제1대구치와 제2대구치의 3/1크기였으며, 상악 제1절치는 2개의 다른 크기의 갈고리 모양이었으며, 하악 제1 절치는 매끈하였다. 뒤쥐의 경우, 치식은 I3/1 C1/1 P3/1 M3/3=32이었고, 상악 제1대구치와 제2대 구치는 균형이 맞는 W형을 가졌고 상악 제3대구치는 다른 대구치의 약 절반 크기였으며, 상악 제1절치는 2개의 비슷한 크기의 갈고리 모양이었으며 하악 제1절치는 매끈하지않은 톱니모양이었다. 치아와 두개골 측정치 비교에서 우수리땃쥐가 3종 중 가장 컸으나(p<0.001), 작은땃쥐와 뒤쥐는 크기에서 차이가 없었다(p>0.05). EDX를 이용한 하악 제1절치와 하악 제1대구치의 법랑질 표본의 정성적 분석으로부터, C, O, P, Ca, Cu가 모든 표본에서 검출되었고 Pb는 몇몇 표본에서만 검출되었다. 3종들에서 이들의 함유량은 통계적 차이를 보이지 않았다(p>0.05). Fe는 붉게 착색된 치아를 가지는 뒤쥐의 법랑질 표면에서만 검출되었다. 따라 서 Fe가 치아의 붉은 착색의 원인이다. 이상의 결과들은 치아 끝의 색을 포함한 치아 형태학적 특징들이 땃쥐속과 뒤쥐속의 분류키가 될 수 있음을 시사하고 있다.

• 대한소아치과학회지
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• 제44권1호
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• pp.28-37
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• 2017

Mineral trioxide aggreagate는 치수 치료제로서 많이 사용되고 있는 재료중 하나이다. 그 중 가장 널리 쓰이고 있는 Proroot white $MTA^{(R)}$는 치아 변색을 일으킨다는 단점이 있다. 이번 연구에서는 MTA 기반 재료들인 Proroot $wMTA^{(R)}$, $Biodentine^{(R)}$, $Endocem^{(R)}$, $RetroMTA^{(R)}$를 치수강에 각각 채워넣어 시간에 따른 치경부의 변색을 비교하고자 하였다. 교정적인 이유로 발치된 75개의 소구치를 사용하여 무작위로 4개의 실험군(n = 60)과 한 개의 대조군(n = 15)으로 나누었다. 치아는 CEJ 하방 2 mm로 수평절단 하였다. 각각의 재료들을 제조사의 지시에 따라 준비한 후 치수강에 채워넣고 입구를 레진을 이용하여 봉인하였다. 치아 색조 측정은 국제조명위원회(Commission International de I'Eclairage, CIE)의 CIE $L^*a^*b^*$ system을 사용하였다. 색조는 분광 광도계를 사용하여 재료를 넣기 전, 재료를 넣고 1일, 1주, 2주, 4주, 8주, 12주, 16주 후로 총 8번 측정하였다. 이원 변량 분산분석(Two way repeated ANOVA)을 사용하여 시간에 따른 CIE $L^*$, $a^*$, $b^*$와 ${\Delta}E$값을 비교 평가하였고 실험군과 대조군과의 통계적 유의성과 상호관계는 본페로니 검정으로 사후 검정하여 p 값이 0.05이하일 때 통계학적으로 유의하다고 간주하였다. Proroot $wMTA^{(R)}$는 시간에 따라 계속적인 $L^*$값의 감소를 보였고, $Endocem^{(R)}$은 재료를 넣은 직 후 육안으로 인지 불가능한 약간의 회색조 변색을 보였으며, $Biodentine^{(R)}$과 $RetroMTA^{(R)}$는 상대적으로 다른 재료보다 색 안정성을 보였다. 결론적으로, 방사선 불투과성 물질로서 산화 비스무스가 포함된 Proroot $wMTA^{(R)}$와 $Endocem^{(R)}$은 치관 변색을 보인 반면, 방사선 불투과성 물질로서 산화 지르코늄이 포함된 $Biodentine^{(R)}$과 $RetroMTA^{(R)}$는 시간에 따른 유의한 색 변화를 보이지 않았다.