• Title/Summary/Keyword: Korean Teeth

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INFLUENCE OF REBONDING PROCEDURES ON MICROLEAKAGE OF COMPOSITE RESIN RESTORATIONS (복합레진 수복 시 재접착 술식이 미세누출에 미치는 영향)

  • Lee, Mi-Ae;Seo, Duck-Kyu;Son, Ho-Hyun;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.35 no.3
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    • pp.164-172
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    • 2010
  • During a composite resin restoration, an anticipating contraction gap is usually tried to seal with low-viscosity resin after successive polishing, etching, rinsing and drying steps, which as a whole is called rebonding procedure. However, the gap might already have been filled with water or debris before applying the sealing resin. We hypothesized that microleakage would decrease if the rebonding agent was applied before the polishing step, i.e., immediately after curing composite resin. On the buccal and lingual surfaces of 35 extracted human molar teeth, class V cavities were prepared with the occlusal margin in enamel and the gingival margin in dentin. They were restored with a hybrid composite resin Z250 (3M ESPE, USA) using an adhesive AdperTM Single Bond 2 (3M ESPE). As rebonding agents, BisCover LV (Bisco, USA), ScotchBond Multi-Purpose adhesive (3M ESPE) and an experimental adhesive were applied on the restoration margins before polishing step or after successive polishing and etching steps. The infiltration depth of 2% methylene blue into the margin was measured using an optical stereomicroscope. The correlation between viscosity of rebonding agents and mciroleakage was also evaluated. There were no statistically significant differences in the microleakage within the rebonding procedures, within the rebonding agents, and within the margins. However, when the restorations were not rebonded, the microleakage at gingival margin was significantly higher than those groups rebonded with 3 agents (p < 0.05). The difference was not observed at the occlusal margin. No significant correlation was found between viscosity of rebonding agents and microleakage, except very weak correlation in case of rebonding after polishing and etching at gingival margin.

Analysis of the Spatial Dose Rates during Dental Panoramic Radiography (치과 파노라마 촬영에서 공간선량률 분석)

  • Ko, Jong-Kyung;Park, Myeong-Hwan;Kim, Yongmin
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.509-516
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    • 2016
  • A dental panoramic radiography which usually uses low level X-rays is subject to the Nuclear Safety Act when it is installed for the purpose of education. This paper measures radiation dose and spatial dose rate by usage and thereby aims to verify the effectiveness of radiation safety equipment and provide basic information for radiation safety of radiation workers and students. After glass dosimeter (GD-352M) is attached to direct exposure area, the teeth, and indirect exposure area, the eye lens and the thyroid, on the dental radiography head phantom, these exposure areas are measured. Then, after dividing the horizontal into a $45^{\circ}$, it is separated into seven directions which all includes 30, 60, 90, 120 cm distance. The paper shows that the spatial dose rate is the highest at 30 cm and declines as the distance increases. At 30 cm, the spatial dose rate around the starting area of rotation is $3,840{\mu}Sv/h$, which is four times higher than the lowest level $778{\mu}Sv/h$. Furthermore, the spatial dose rate was $408{\mu}Sv/h$ on average at the distance of 60 cm where radiation workers can be located. From a conservative point of view, It is possible to avoid needless exposure to radiation for the purpose of education. However, in case that an unintended exposure to radiation happens within a radiation controlled area, it is still necessary to educate radiation safety. But according to the current Medical Service Act, in medical institutions, even if they are not installed, the equipment such as interlock are obliged by the Nuclear Safety Law, considering that the spatial dose rate of the educational dental panoramic radiography room is low. It seems to be excessive regulation.

Effect of Endoscopic Forceps on the Quality of Duodenal Mucosal Biopsy in Healthy Cats (고양이 십이지장 점막 생검 시 내시경 생검 겸자가 조직의 질에 미치는 영향에 관한 연구)

  • Won, Jin-Hee;Hong, Il-Hwa;Jang, Hyo-Mi;Eom, Na-Young;Jee, Cho-Hee;Jung, Hae-Won;Kang, Byeong-Teck;Jeong, Dong Wook;Jung, Dong-In
    • Journal of Veterinary Clinics
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    • v.32 no.2
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    • pp.141-147
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    • 2015
  • Based on the results of previous studies, endoscopic biopsy sample's quality has a major impact on its adequacy for histopathology, and that the nature of the biopsy forceps can influence the specimen quality. The present study compared the effects of three different types of endoscopic biopsy forceps and two different operators on sample quality and adequacy for histopathology in three healthy cats. Every biopsy was performed between the major papilla and caudal duodenal flexure, and each operator performed five biopsies with each type of forceps on each cat, for a total of 90 biopsies. One pathologist evaluated the quality and adequacy of the obtained samples. Biopsies performed with large-cup forceps provided heavier and longer samples than the standard round forceps. With the same size forceps, the presence of alligator teeth had no effect on sample quality or adequacy for histopathological examination and assessment. Based on the results of the present study, although the standard round forceps could be used to obtain adequate samples for histopathology, large-cup forceps such as the standard oval and alligator jaw type have the advantage of obtaining high quality endoscopic samples.

Microtensile bond strength of resin inlay bonded to dentin treated with various temporary filling materials (임시 가봉재가 상아질과 레진 인레이의 미세인장 결합 강도에 미치는 영향)

  • Kim, Tae-Woo;Lee, Bin-Na;Choi, Young-Jung;Yang, So-Young;Chang, Hoon-Sang;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann
    • Restorative Dentistry and Endodontics
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    • v.36 no.5
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    • pp.419-424
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    • 2011
  • Objectives: This study was aimed to determine the effects of temporary sealing materials on microtensile bond strength between resin-coated dentin and resin inlay and to compare the bonding effectiveness of delayed dentin sealing and that of immediate dentin sealing. Materials and Methods: The teeth were divided into 4 groups: group 1, specimens were prepared using delayed dentin sealing after temporary sealing with zinc oxide eugenol (ZOE); group 2, specimens were prepared using immediate dentin sealing and ZOE sealing; group 3, specimens were prepared using immediate dentin sealing and Dycal (Dentsply) sealing; group 4, specimens were prepared using immediately sealed, and then temporarily sealed with a resin-based temporary sealing material. After removing the temporary sealing material, we applied resin adhesive and light-cured. Then the resin inlays were applied and bonded to the cavity with a resin-based cement. The microtensile bond strength of the sectioned specimens were measured with a micro-tensile tester (Bisco Inc.). Significance between the specimen groups were tested by means of one-way ANOVA and multiple Duncan's test. Results: Group 1 showed the lowest bond strength, and group 4 showed the highest bond strength (p < 0.01). When temporary sealing was performed with ZOE, immediate dentin sealing showed a higher bonding strength than delayed dentin sealing (p < 0.01). Conclusions: Based on these results, immediate dentin sealing is more recommended than delayed dentin sealing in bonding a resin inlay to dentin. Also, resin-based temporary sealing materials have shown the best result.

COMPARISON OF THE MARGINAL LEAKAGE OF SEVERAL FILLING MATERIALS ON CLASS V CAVITIES (제오급와동(第五級窩洞) 수복(修復)에 사용(使用)되는 수종(數種) 충전재(充塡材)의 변연누출(邊緣漏出) 비교(比較))

  • Kim, Mi-Ok;Cho, Kyew-Zeung
    • Restorative Dentistry and Endodontics
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    • v.14 no.2
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    • pp.20-29
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    • 1989
  • The purpose of the study is to evaluate the degree of the marginal leakage of class V cavities with 4 brands of esthetic filling materials by means of the dye penetration at the enamel & dentinal margins. 160 cavities of class V were prepared on the buccal & lingual surfaces of 80 extracted premolar teeth, which divided into 4 groups. The four groups of cavities were filled with Durafill$^{(R)}$-Durafill bond$^{(R)}$(KuIzer & Co GmbH), Bisfil M$^{(R)}$-Resin bond$^{(R)}$(BISCO Inc.), Silux$^{(R)}$-Scotchbond$^{(R)}$(3M Co.) and Fuji ionomer$^{(R)}$(type II, G-C Co.) each. All specimens were immersed in 2% methylene blue dye solution for 24 hours at $37^{\circ}C$ after a 30-second thermocycling at $4^{\circ}C$ and $60^{\circ}C$ and longitudinally sectioned with diamond disk into two parts. The results were as follows : 1. At enamel margins, the group filled with Durafill$^{(R)}$-Durafill bond$^{(R)}$, Bisfil M$^{(R)}$-Resin bond$^{(R)}$ and Silux$^{(R)}$-Scotchbond$^{(R)}$ show no significant difference each other(p>0.05), and the above groups show less marginal leakage comparing with the group filled with Fuji ionomer$^{(R)}$(p<0.01). 2. At dentinal margins, the group filled with Silux$^{(R)}$-Scotchbond$^{(R)}$ or Fuji ionomer$^{(R)}$ show less marginal leakage than that with Durafill$^{(R)}$-Durafill bond$^{(R)}$ or Bisfil M$^{(R)}$-Resin bond$^{(R)}$(p<0.01). 3. The enamel margins show less marginal leakage than dentinal margins in all the class V cavities(p<0.01).

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STUDY ON THE INTERFACE BETWEEN LIGHT-CURED GLASS IONOMER BASE AND INDIRECT COMPOSITE RESIN INLAY AND DENTIN (기저재용 광중합형 글래스아이오노머의 치질 및 복합 레진 인레이에 대한 접착양상)

  • Lee, Song-Hee;Kim, Dong-Jun;Hwang, Yun-Chan;Oh, Won-Mann;Hwang, In-Nam
    • Restorative Dentistry and Endodontics
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    • v.30 no.3
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    • pp.158-169
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    • 2005
  • This study was done to evaluate the shear bond strength between light-cured glass ionomer cement (GIC) base and resin cement for luting indirect resin inlay and to observe bonding aspects which is produced at the interface between them by SEM. Two types of light cured GIC (Fuji II LC Improved, GC Co. Tokyo, Japan and Vitrebond$^{TM}$, 3M, Paul Minnesota U.S.A) were used in this study. For shear bond test, GIC specimens were made and immersed in 37$^{\circ}C$ distilled water for 1 hour, 24 hours, 1 week and 2 weeks. Eighty resin inlays were prepared with Artglass$^{(R)}$ (Heraeus Kultzer Germany) and luted with Variolink$^{(R)}$ II (Ivoclar Vivadent, Liechtenstein). Shear bond strength of each specimen was measured and fractured surface were examined. Statistical analysis was done with one-way ANOVA. Twenty four extracted human third molars were selected and Class II cavities were prepared and GIC based at axiopulpal lineangle. The specimens were immersed in 37$^{\circ}C$ distilled water for 1 hour, 24 hours, 1 week and 2 weeks. And then the resin inlays were luted to prepared teeth. The specimens were sectioned vertically with low speed saw. The bonding aspect of the specimens were observed by SEM (JSM-5400$^{(R)}$, Jeol, Tokyo, Japan) .There was no significant difference between the shear bond strength according to storage periods of light cured GIC base. And cohesive failure was mostly appeared in GIC On scanning electron micrograph, about 30 - 120 $\mu$m of the gaps were observed on the interface between GIC base and dentin. No gaps were observed on the interface between GTC and resin inlay.

THE INFLUENCE OF THE VITAL BLEACHING AGENTS ON TRANSLUCENCY OF THE BOVINE ENAMEL (생활치 미백제가 우치 법랑질의 투명도에 미치는 영향)

  • Kim, Dong-Jun;Kim, Young-Ju;Kim, Hak-Geun;Park, Eun-Jong;Seo, Eun-Ju;Hwang, Yun-Chan;Oh, Won-Mann;Hwang, In-Nam
    • Restorative Dentistry and Endodontics
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    • v.30 no.3
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    • pp.178-183
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    • 2005
  • This study was done to evaluate whether vital bleaching agents could influence on the translucency of the bovine enamel. The anterior bovine teeth that were extracted one day before and without any gross discoloration were obtained and then were preserved in physiologic saline. 6 mm cylindrical tooth specimens were fabricated with diamond puncher perpendicularly on labial surface of bovine tooth. After embedded in transparent acrylic resin with labial surface being exposed, they were cut to a thickness of 1.2 mm with low speed diamond saw (Isomat, Buehler Co., Lake Bluff, IL, USA). They were smoothly ground to 1 mm thickness of enamel with sandpaper. 24 specimens were randomly divided into 3 groups and control group respectively. Opalescence (10% carbamide peroxide, Ultradent, South Jordan, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) and Opalescence F (15% carbamide peroxide with fluoride, Ultradent, USA) were applied on labial sides of the bovine enamel for 7 days (bleaching agents were reapplied every 24 hours) and the opposite surface was contacted to cotton that soaked in distilled water. The control group was soaked in distilled water. Three stimulus value X, Y and Z were evaluated with colorimeter (Color ' Color Differencerneter, Model TC-6FX, Tokyo Denshoku Co., Japan) on the labial surface of all specimen three times on white and black background plate before the bleaching agents were applied and on 3rd, 5th and 7th day after applied. The degree of translucency was normally assessed by measuring the inverse property, opacity (contrast ratio). 10% Opalescence, 15% Opalescence-F, and control group showed no significant variation in the translucency of bovine enamel, However Rembrandt decreased the translucency of it (p < 0.01).

Mechanism by which periodontitis may contribute to atherosclerosis (치주염이 동맥경화에 기여하는 기전에 관한 연구)

  • Han, Seung-Hee;Kim, Kyung-Hwa;Yang, Seung-Min;Chung, Hyun-Ju;Choi, Yoon-Sik;Han, Soo-Boo;Chung, Chong-Pyoung;Rhyu, In-Chul
    • Journal of Periodontal and Implant Science
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    • v.32 no.4
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    • pp.837-846
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    • 2002
  • 그람 음성균의 감염에 의한 만성 염증질환인 치주염이 동맥경화를 동반한 허혈성 심장질환 (협심증이나 심근 경색)을 일으킬 수 있는 위험인자로 작용할 수 있다는 보고가 있었다. 그러나, 그 기전에 관해서는 명확하게 알려져 있지 않다. 작용기전의 하나로서, 치주염에 의해 치주조직에서 국소적으로 생긴 염증성 싸이토카인(IL-1${\beta}$, IL-6, $PGE_2$, TNF-${\alpha}$)이 혈행을 따라 이동하여 심혈관에서 동맥경화를 일으킬 수 있다는 가설이 제시되고 있는데, 이 가설을 검증해 보고자 한다. 서울대학교 병원 순환기 내과에 불안정 협심증이나 심근경색으로 입원한 환자 및 과거 이 질환의 병력을 갖고 있거나 검진 목적으로 내원하여 관상동맥 조형술을 받은 환자들 중 동맥경화로 진단받은 사람을 실험군(24명)으로 하고, 동맥경화로 진단받지 않은 사람을 대조군(12명)으로 하였다. 치주질환의 활성도를 나타내는 치은 지수, 치태 지수, 치주낭 깊이, 부착 상실을 측정하였다. Paper strip을 실험대상 치아(Ramfjord's teeth)들 중에서 가장 깊은 치주낭을 가진 두 개의 치아를 택하여 각 치아의 가장 깊은 치주낭에 30초간 삽입한 후 밀폐된 plastic tube에 넣고 ELISA kit를 이용하여 IL-1${\beta}$, IL-6, TNF-${\alpha}$, $PGE_2$의 농도를 측정하였다. 환자의 plasma에서도 동일한 싸이토카인의 농도를 측정하였다. 설문조사를 통해 동맥경화의 위험 인자로 간주되어온 고혈압, 당뇨, 가족력, 심근경색이나 협심증의 기왕력, 흡연의 유무를 기록하였다. 혈액검사를 하여 total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, WBC, CRP (C-reactive protein)의 농도를 측정하였다. 치주조직에 대한 임상 검사 결과 치은의 염증상태를 나타나는 지표인 치은 지수에서만 실험군이 대조군에 비해 유의할 정도 (p=0.0174)로 높게 나타났고, 만성적인 염증의 결과로 인한 치조골의 사실 정도를 나타내는 치주낭 깊이나 부착 상실에서는 유의할 만한 차이를 보이지 않았다. 치주낭에서 측정한 염증성 싸이토카인 중 IL-1${\beta}$, $PGE_2$가 실험군에서 유의할 만한 차이 (p=0.005, 0.022)를 보이며, 더 높은 농도로 나타났고, TNF-${\alpha}$는 대조군에서 유의성 있게 (p=0.009) 높게 나타났다. 그러나, plasma의 싸이토카인이나, serum lipid/lipoprotein, C-reactive Protein, WBC는 유의할 만한 차이를 보이지 않았다. 또한 치은열구액내의 싸이토카인과 이에 상흥하는 싸이토카인 간에 상관관계는 관찰되지 않았다. 다변량 로지스틱 회귀분석 결과, 치은열구액내의 IL-1${\beta}$와 TNF-${\alpha}$ 만이 동맥경화와 유의성 있는 관련성을 보였고, 특히 IL-1${\beta}$와 교차비는 273으로 상당한 관련성을 보여주었다. 결론적으로, 치주조직에서 국소적으로 생긴 염증성 싸이토카인이 그대로 혈행으로 이동하여 혈장내의 싸이토카인 농도를 높이는 것은 아니다. 그러나, 치주염으로 인해 치은열구내액내에 국소적으로 증가된 염증성 싸이토카인은 동맥경화와 상당한 관련성을 가진다.

An effect of Dentin Bonding Procedure on the Shear Bond Strength of Resin Cement to Porcelain Restoration (도재 수복물 합착시 상아질 접착 술식이 레진 시멘트의 전단결합강도에 미치는 영향)

  • Kang, Hae-Jin;Shin, Soo-Yeon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.1
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    • pp.67-78
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    • 2012
  • The purpose of this study was to determine whether there were differences in shear bond strength to human dentin using IDS technique compared with DDS. Forty freshly extracted human molars were and devided into 4 groups. The control group specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent and cemented with resin cement. The IDS/SE(immediate dentin sealing, Clearfil$^{TM}$ SE Bond) and IDS/SB (immediate dentin sealing, Adapter$^{TM}$ Single Bond 2) specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent(Clearfil$^{TM}$ SE Bond and Adapter$^{TM}$ Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. IDS/SE, IDS/SB and DDS specimens were thermocycled. Following that delay, specimens were cemented with resin cement. The dentin bonding agent was left unpolymerized until the application of porcelain restoration. Shear bond strengths were measured using a universal testing machine. Specimens also were evaluated for mode of fracture using an optical microscope. The mean shear bond strengths of control group and IDS/SE groups were not statistically different from one another. The bond strength of IDS/SE group had a significantly higher mean than that of DDS group. There was no significant difference in the mean shear bond strength between IDS/SB(4.11MPa) and DDS group. The evaluation of failure modes indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS group were interfacial. When preparing teeth for indirect ceramic restoration, IDS with Clearfil$^{TM}$ SE Bond results in improved shear bond strength compared with DDS.

A Spectrophotometric Study on Color Differences between Various Light-Cured Composite Resins and Shade Guides (광중합형 복합레진과 shade guide의 색차에 관한 연구)

  • Lim, Kyung-Min;Lee, Min-Ho;Song, Kwang-Yeob
    • Journal of Dental Rehabilitation and Applied Science
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    • v.25 no.1
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    • pp.13-22
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    • 2009
  • The composite resin, due to its esthetic quality, is considered the material of choice for restoration of anterior teeth. To get a satisfactory result in the composite resin restorations, it is necessary to choose right shade. At present, most of the commercial composite resins are based on the Vita Lumin shade guides or shade guides that are provided by their company, but color differences among them might be expected even using the same shade in various materials. This study is to measure color differences between various light-cured composite resins and shade guides and to provide the clinicians with information which may aid in improved color match of esthetic restoration. Four kinds of light-cured composite resins (Gradia Direct (GD), Z250 (Z250), Clearfil AP-X (AP-X), Esthet X (E X)) and shade guides with A2 and A3 shade were used. Three specimens of each material and one specimen of each shade guide were made. Each composite resin was filled into the Teflon mold (1.35 mm depth, 8 mm diameter), followed by compression, polymerization and polishing with wet sandpaper. Shade guides were grinded with polishing stones and rubber points to a thickness of approximately 1.35 mm. Color characteristics were performed with a spectrophotometer(color i5, GretagMacbeth, USA). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$, $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E^*ab$) between composite resins and shade guides. CIE standard D65 was used as the light source. The results were as follows : 1. Among the $L^*$, $a^*$, $b^*$ values of most of 4 kinds of composite resin specimens which are produced by same shade, there were significant differences(p<0.05). 2. Among all 4 kinds of composite resin specimens which are produced by same shade, there were color differences that is perceptible to human eye(${\Delta}E^*>3.3$). 3. Between most of composite resin specimens investigated and their corresponding shade guides, there were color differences that is perceptible to human eye(${\Delta}E^*>3.3$). 4. In the clinical environment, it is recommended that custom shade guides be made from resin material itself for better color matching. Shade guides supplied by manufacturers or Vita Lumin shade guide may not provide clinicians a accurate standard in matching color of composite resins, and there are perceptible color differences in most of products. Therefore, it is recommended that custom shade guides be made from resin material itself and used for better color matching.