Effect of hydrogel-based antibiotic intracanal medicaments on crown discoloration

Yaghmoor Rayan B.,Platt Jeffrey A.,Spolnik Kenneth J.,Chu Tien Min Gabriel,Yassen Ghaeth H. 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.4

Objectives This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. Materials and Methods Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]2; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. Results Ca(OH)2 and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. Conclusions Ca(OH)2 and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP. Objectives This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. Materials and Methods Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]2; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. Results Ca(OH)2 and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. Conclusions Ca(OH)2 and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP.

국내 맥주용 2조 겉보리 품종의 종실 변색이 원맥 품질에 미치는 영향

박종철 ( Jong Chul Park ),김경훈 ( Kyeong Hoon Kim ),강천식 ( Chon Sik Kang ),조광민 ( Kwang Min Cho ),신상현 ( Sang Hyun Shin ),최재성 ( Jae Seong Choi ),박철수 ( Chul Soo Park ) 전북대학교 농업과학기술연구소 2013 농업생명과학연구 Vol.44 No.2

국내 육성 맥주용 2조 겉보리 20품종에 대해 수확기에 종실 변색과 관련한 곰팡이 분포 및 원맥의 품질에 미치는 영향을 조사하였다. 종실변색 증상은 주로 흑갈색 반점, 붉은 부분 변색이나 원형 반점을 나타내었다. 종실 변색과 관련한 곰팡이를 분리한 결과 Alternaria spp.이 각 조사연도에 평균69.1%와 72.2%의 분리율로 다른 곰팡이에 비해 우점하는 결과를 보였다. Epicoccum spp., Fusarium spp.과 Aspergillus flavus는 연차간 차이를 보이며 발생하였으며, 2011년과 2012년 수확기에 품종별 종실 변색율은 2011년에 평균 19.9%로 2012년 13.2%에 비해 높았다. 종실 변색율은 환경 변이 뿐만 아니라 품종간에도 차이를 나타내었으며, 사천 6호와 다진보리는 9% 이하의 종실 변색율로 다른 품종에 비하여 저항성으로 나타났다. 이러한 저항성 품종은 대부분의 원맥 품질 특성에서 차이가 없었지만, 베타글루칸 함량과 수감수성이 낮은 것으로 나타나, 향후 맥아 및 맥즙 특성에 종실 변색율이 영향을 미칠 것으로 생각된다. The objective of this study was to investigate the effect of kernel discoloration on grain quality of two-rowed hulled malting barley cultivars in Korean for two years, 2011 and 2012. The symptoms were blackish spot, partly red and circular spot on the grain. Alternaria spp. was dominant fungi and rate of kernel discoloration was 69.1% for 2011 and 72.2% for 2012. Average kernel discoloration rate in Korean hulled malting barley was 19.9% for 2011 and 13.2% for 2012. Variations in kernel discoloration between cultivars were larger than those of growing seasons. Two culivars, cvs. Sacheon 6 and Dajinbori, showed resistant to kernel discoloration, which showed below 10% of kernel discoloration rate. While, two susceptible barley cultivars, cvs. Samdobori and Daeyoungbori, exhibited higher than 22.2% of kernel discoloration rate. There were no significant differences in characteristics of grain qualities between resistant and susceptible cultivars to kernel discoloration. However, β-glucan content and water sensitivity of resistant cultivars to kernel discoloration (<8%) showed lower than (3.6 and 5.9%, respectively) those of susceptible cultivars with over 27.6% (4.3 and 16.9%, respectively).

Oak sprout dynamics after a 1996 stand-replacing fire in Korea

황혜진,임주훈,류성렬 한국산림과학회 2011 Forest Science And Technology Vol.7 No.4

Sprouting is an effective means to re-establish a forest after forest fires. However, these sprouts are vulnerable to fungirelated infection (e.g., discoloration, heart rot, and decay) through wounds on primary stumps or root systems to produce low-quality timber. A stand-replacing fire consumed 3762 ha of pine-dominated forests in Goseong-gun, Gangwon-do in 3 days in 1996 and a low-intensity fire swept the area again in 2000. We established five 9 6 9 m2 plots in the area designated for natural regeneration, where oak species (i.e., Quercus dentata Thunb., Q. mongolica Fisch. ex Ledeb, Q. serrata Thunb. ex. Murray, Q. variabilis Blume) replaced Japanese red pine (Pinus densiflora Siebold & Zucc.) forests. All the measurements were carried out in April 2010. The objectives of the study were to evaluate the natural regeneration patterns of oak species and to assess the factors associated with oak sprout discoloration. Sprout production was the highest in the third growing season from each fire in 1996 and 2000, implying that oak species might focus more on root development for the first few years and move onto sprout production. A ttest was employed to evaluate the difference between normal and discolored sprouts. There were significant differences in height, DBH, and age between normal and discolored sprouts (P 5 0.05), except for those of Q. dentata. Additionally, correlation analysis was conducted between sprout discoloration occurrences and sequentially shifted annual sprout production to assess the time-lagged relationship. Discoloration occurrences showed the highest correlation coefficient with annual sprout production at a 2-year advance (r ¼ 0.36, 0.82, 0.62, and 0.80 for Q. dentata,Q. mongolica, Q. serrata, and Q. variabilis, respectively), indicating that discoloration tended to occur within 2 years after the sprout production. Approximately 50% of sprouts were discolored showing that discoloration is a common phenomenon in oak sprouts after fire and oak sprouts would likely produce less desirable timbers. The results suggest that fire-induced oak forests should be managed for small timber forests with short rotation.

미성숙영구치의 복합항생제 적용에 의한 변색의 처치: 증례보고

박소연,김영재,김정욱,장기택,이상훈,김종철,한세현,현홍근 大韓小兒齒科學會 2012 大韓小兒齒科學會誌 Vol.39 No.1

The concept of revascularization of necrotic pulps regained interest and became an alternative conservative treatment option for young permanent teeth with immature roots. Revascularization of immature teeth with apical periodontitis depends mainly on disinfection of the canal. Since the infection of the root canal system is considered to be polymicrobial, a combination of drugs would be needed to treat the diverse flora. A triple antibiotic mixture of metronidazole, ciprofloxacin, and minocycline was used as an intracanal medicament. However, discoloration was developed after applying the triple antibiotic mixture. It is believed that the marked discoloration is related to the use of minocycline. The aim of this article was to present cases of coronal discoloration after triple antibiotic therapy in immature tooth and was treated with bleaching technique to control coronal discoloration. In conclusion, revascularization by using triple antibiotics promotes a paradigm shift in treating endodontically involved permanent teeth. However, we should understand that triple antibiotics containing minocycline induces tooth discoloration. Further research to prevent coronal discoloration should be investigated and suggested for the safe use of triple antibiotics. 괴사된 미성숙영구치의 치수치료에 있어서 치수의 재혈관화를 통해 치근단 발육 및 치근형성을 지속하려는 개념이 소개됨 으로써 현재 미성숙영구치의 치수치료의 대안으로 제시되고 있다. 이러한 치근단 염증을 가진 미성숙 영구치의 재혈관화를 위해서는 가장 중요한 것이 근관내 감염된 부분을 확실히 제거하는 살균(disinfection)이다. 근관 내 감염은 여러 세균의 복 합작용으로 일어나기 때문에 철저한 살균에 사용되는 약제의 조합은 다양한 범위의 균주를 모두 제거 가능해야한다. Metronidazole(MN), ciprofloxacin(CF), minocycline(MC)의 세 가지 복합항생제가 약제로 사용되고 있으나 이 복합항생 제 적용 후 치관변색을 일으키는 사례가 보고되고 있다. 이러한 치관변색은 항생제의 성분 중 MC에 의한 것으로 여겨지고 있으며, 본 증례에서는 복합항생제 적용에 의해 야기된 치관변색의 증례를 소개하고 이를 표백술로 처치하여 최종 수복한 증 례를 보고하였다. 복합항생제 적용을 통해 미성숙영구치의 치수치료에 새로운 패러다임을 제시한 것은 분명하지만 치관변색 등의 부작용이 있음을 인지하고 치관변색을 사전에 예방하고 최소화하기 위해 다양한 방법이 강구되어야 할 것이다.

십이지장 제 2부에서 점막 백색 변조의 의의 -위 기능면에서-

양태영 ( Tae Yeong Yang ),윤홍선 ( Hong Sun Yoon ),김민수 ( Min Su Kim ),황성준 ( Seoung Joon Hwang ),박효진 ( Hyo Jin Park ),박찬일 ( Chan Il Park ) 대한소화기기능성질환·운동학회 2006 Journal of Neurogastroenterology and Motility (JNM Vol.12 No.2

배경: 상부 위장관 내시경 검사시 십이지장 제 2부에서 흔히 보이는 분홍색의 점막 색조와는 달리 점막의 백색 변조를 가끔 볼 수 있다. 이에 관한 문헌은 거의 없고 지방을 함유한 대식세포의 침착에 비롯된다는 주장이 있을 뿐이다. 저자들은 백색 변조를 위 기능면에서의 의미와 조직학적인 이상 유무에 대해서 알아 보았다. 대상 및 방법: 십이지장 제 2부에 백색 변조가 있는 기능성 소화불량증 환자(I군) 14명, 백색 변조가 없는 기능성 소화불량증 환자 (II군) 11명, 그리고 상부 위장관 증세가 없으며 백색 변조가 없는 정상 대조군 10명을 대상으로 상부 위장관 증상, 위 배출 시간 및 조직학적 검사 소견을 비교하였다. 결과: I, II군에서 동반 질환, 증상 지수간 유의한 차이는 없었다. 위 배출 시간 [TI/2 (min)]은 I군 147.4분, II군 99.6분, 정상 대조군은 75.8분으로, I군은 각각 II군, 정상 대조군에 비해서 유의한 위 배출 시간의 지연이 있었으며(p<0.05), II군과 정상 대조군 간에는 유의한 차이가 없었다. 세 군간의 유의한 조직학적 차이점은 없었으며 백색 변조된 점막에서 지방을 함유하는 특이적인 소견은 없었다. 결론: 기능성 소화불량증 환자에서 상부 위장관 내시경 검사를 실시할 때 드물게 볼 수 있는 십이지장 제 2부 점막의 백색 변조는 위 기능적인 측면에서 위 배출 시간 지연과 연관이 있음을 알 수 있었다. Background/Aims: A mucosal `whitish discoloration` of the duodenal second portion may be discorvered during esophagogastroduodenoscopy (EGD). This study investigated the gastric functional implication and histological abnormalities of mucosal `whitish discoloration`. Methods: The upper gastrointestinal symptoms, gastric emptying time and histology findings were compared in patients with functional dyspepsia (FD) showing mucosal `whitish discoloration` of the duodenal second portion (group I), FD patients without `whitish discoloration` (group II), and normal controls who have neither symptoms nor `whitish discoloration` (normal controls). Results: There was a significant difference between group I (147.6 min) and group II (99.6 min) or normal controls (75.8 min). However there was no difference between group II and normal controls. There was no histological difference in the three groups. In particular, there was no mucosal infiltration of macrophage in second portion of duodenum. Conclusions: Mucosal `whitish discoloration` of the duodenal second portion, uncommon occurrence in EGD, can be correlated with a delayed gastric emptying time. (Kor J Neurogastroenterol Motil 2006;12:122-126)

압화용 오이 과실 표피의 건조시 테이프 부착과 황산구리, 아스코르빈 산 및 열수 처리가 변색에 미치는 영향

박윤점 ( Yun Jum Park ),김현주 ( Hyun Ju Kim ),최경혜 ( Koung Hea Choi ),임명희 ( Myung Hee Im ),조자용 ( Ja Yong Cho ),허북구 ( Buk Gu Heo ) 한국화예디자인학회 2007 한국화예디자인학 연구 Vol.16 No.-

This study was carried out to look for the effective methods to prevent the discoloration of cucumber for the pressed flower. We have also removed the flesh of cucumber fruits, and investigated into the effects of the whether or not of the sticking with tape, the concentration of copper sulfate and ascorbic acid solution (0.5, 1, 2, 4, 8 and 16%), and the immersion period (5, 10, 15 and 30 minutes) on the chromaticity of cucumber after drying for 64 hours and ultraviolet radiation. The treatment of 4% copper sulfate solution for 15 minutes was effective. That sticking with tape were most effective in the immersion treatment of 8% copper sulfate solution for 15 minutes. That immersed in 6% vitamin solution for 5 minutes, and 0.5, 1, 2 and 4% vitamin solution for 10 minutes were effective for the prevention of discoloration. That treated 1, 2 and 4% ascorbic acid solution for 10 or 20 minutes after sticking that with tape were also effective. That immersed in the heated water for 10 seconds, and that for 30 seconds after sticking with tape were also effective for the prevention of discoloration. Generally sticking tape to the cutting parts of cucumber was effective for the prevention of discoloration.

색차계를 이용한 방사무늬김(Pyropia yezoensis Ueda)의 황백화 평가

이상용,김영희,이지은,황은경 한국환경생물학회 2018 환경생물 : 환경생물학회지 Vol.36 No.4

Pyropia yezoensis is one of the most extensively cultivated seaweeds used as food in Korea. However, the quality and yield of Pyropia farms are frequently affected by outbreaks of thallus discoloration. The objective of this study was to develop a simple and rapid method to evaluate P. yezoensis discoloration caused by nutrient deficiencies. A colorimeter was used to quantify the color of P. yezoensis in nutrient deficient media over 10 days. Quantitative values of lightness (L), redness (a), and yellowness (b) measured with a colorimeter were used as indicators of P. yezoensis discoloration. The vacuoles of P. yezoensis were observed at 4 days and swelled gradually from 6 days onward. The three colorimeter parameters L, a, and b values showed significantly different values with culture period. The lightness (L) value was darker initially, and continued to lighten over culture period. The yellowness (b) value increased, but the redness (a) value decreased throughout this study. The a/b ratio and redness (a) values from the colorimeter were important P. yezoensis color change indicators. The discoloration group of P. yezoensis had quantitative values for parameters of L above 70, a below 2.6, and b above 15.0. The results of this study showed that quantitative colorimetric measurements can be used as tools for simple and rapid detection of P. yezoensis discoloration. 김은 한국에서 가장 경제성이 높은 양식 해조류이다. 그러나 최근 김 양식장에서 발생하는 황백화 현상으로 인해 엽체의 변색과 탈락이 자주 유발되어 수산업에 큰 피해를 유발하고 있다. 이 연구는 영양염 부족에 의한 김 황백화를 간단하고 빠르게 평가할 수 있는 방법을 개발하기 위한 목적으로 수행되었다. 10일 동안 빈영양 해수에서 배양한 방사무늬김 엽체의 색도를 정량화하기 위해 색차계를 사용하였다. 색차계로 측정한 명도 (L), 적색강도 (a)와 노란색강도 (b) 값들로 방사무늬김의 황백화를 평가하였다. 방사무늬김 엽체의 액포는 4일차부터 관측되었으며, 6일차부터 액포가 증대하였다. 색차계의 L, a와 b값은 배양시간에 따라 유의한 차이를 보였다. 명도 (L)는 시간의 경과에 따라 어두움에서 점차 밝아졌다. 노란색강도 (b) 값은 시간에 따라 증가하였으나, 적색강도 (a) 값은 감소하였다. 색차계의 a/b 비와 적색강도 (a) 값은 방사무늬김의 색도 차이를 구분하는 주요한 요인이었다. 황백화된 방사무늬김은 명도 (L) 70 이상, 적색강도 (a) 2.6 이하와 노란색강도 (b) 15.0 이상의 정량적인 값으로 구분되었다. 이 연구결과 색차계는 김 황백화의 정도를 손쉽고 빠르게 진단할 수 있는 유용한 도구로 이용할 수 있음을 밝혔다.

폴리쉬 사용으로 인한 네일 변색에 관한 연구

이영숙 ( Young Suk Lee ),박영선 ( Young Seon Park ) 복식문화학회 2011 服飾文化硏究 Vol.19 No.2

Due to rapid growth of nail art industry, various materials and expression tools are have been developed. Increasing number of consumers favor diverse nail art techniques including painting and artificial tips in addition to basic care such as cuticle trimming or coloring. Accordingly, the diversity of polish colors has been settled as a concept of total fashion in addition to the clothes and accessories. As the result, nails may be damaged or discolored. A study the nail discoloration by using polish was purposed that contribute to the development of nail protective products. The tests were conducted with 20 college students for six months from March 3 to Aug. 28, 2009, using digital camera as the measurement apparatus. The students were classified into two groups which applied bright polish (white, beige, pink series) and dark polish (purple, blue, black series), and then divided into the groups applied and not applied the base coat which is known to be effective in preventing nail discoloration, and the groups applied and not applied tonic. The students applied polish for one week, and removed the polish with remover and photographed to examine the degree of nail discoloration. Dark colored polished resulted in earlier coloration and discoloration than the bright colored ones. Base coat could prevent coloration and the color changes of hyponychium and eponychium were lighter than the cases not applied with base coat. Tonic could delay coloration and reduced the color changes of hyponychium showing that tonic was effective for preventing coloration and discoloration of nail in addition to nutrition.

Al2(SO4)3, AlK(SO4), MgSO4 및 CuSO4의 희석액 열탕처리가 압화용 황색 카네이션 꽃잎의 변색에 미치는 영향

박윤점 ( Yun Jum Park ),안정숙 ( Hung Suk Ah ),김현아 ( Hyun A Kim ),김현주 ( Hyun Ju Kim ),최경혜 ( Koung Hea Choi ),김유진 ( Yu Jin Kim ),허북구 ( Buk Gu Heo ) 한국화예디자인학회 2008 한국화예디자인학 연구 Vol.19 No.-

This study was conducted to develop the preservation technique of materials for the pressed flower from discoloration. We have collected yellow carnation petals, and immersed that in Al2(SO4)3, AlK(SO4), MgSO4 and CuSO4 solution diluted with hot distilled water (85-90℃) by 0, 5, 10, 20 and 30% for 30 seconds. We dried and applied petals ultraviolet rays for 21 days and examined into those discoloring degree. Hunter L*, a*, b* and △E* values for that immersed in Al2(SO4)3 and MgSO4 solution diluted by 30% showed the least discoloring degree. Discoloration of carnation petals in terms of Hunter L*, a* and b* values immersed in 30% diluted AlK(SO4 ) solution, and △E* values in 5% solution had the least changes compared with that in control. Those hunter L*, a*, b* and E* values treated with 20% CuSO4 diluted solution had the smallest changes. Consequently, it was assumed that immersing the yellow carnation flowers in diluted Al2(SO4)3, AlK(SO4), MgSO4 and CuSO4 solution was a appropriate way to preserve the petals from discoloration for the pressed flower.

Incidence of Dental Discoloration After Tetracycline Exposure in Korean Children: A Nationwide Population-Based Study

Lee Ji Young,Kim Eun Hwa,Lee Myeongjee,Shin Jehee,Lim Sung Min,Baek Jee Yeon,Kim MinYoung,Ahn Jong Gyun,Kang Chung-Min,Jung Inkyung,Kang Ji-Man 대한소아감염학회 2024 Pediatric Infection and Vaccine Vol.31 No.1

Purpose: Tetracycline is not recommended for children under 12 by guideline due to the risk of tooth discoloration. We aimed to assess the incidence of dental discoloration in Korean children prescribed tetracyclines and investigate whether its risk was greater in tetracyclineexposed children than in the general population. Methods: This population-based cohort study using the Health Insurance Review and Assessment service database included children aged 0–12 years exposed to tetracyclines for at least 1 day between January 2008 and December 2020. The primary outcome was the incidence rate of dental discoloration ≥6 months after prescription, and the standardized incidence ratio (SIR) was evaluated as secondary outcome. Results: 56,990 children were included—1,735 and 55,255 aged <8 and 8–12 years, respectively. 61% children were prescribed tetracycline for <14 days with mostly secondgeneration tetracyclines, doxycycline (61%) and minocycline (35%). The 5- and 10-year cumulative incidence rates of dental discoloration were 4.1% (95% confidence interval [CI], 3.0–5.7%) and 5.7% (95% CI, 4.1% to 7.8%), respectively, in the 0–7 years age group and 0.8% (95% CI, 0.7% to 0.9%) and 1.3 (95% CI, 1.1% to 1.4%), respectively, in the 8–12 years age group. Tetracycline exposure did not increase such risk compared to that in the general population (SIR, 1.08; 95% CI, 0.69 to 1.60). Conclusions: The incidence of dental discoloration was lower than previously suggested. Relieving the age restriction for prescribing tetracyclines may be considered.