光固化灯的类型和特点

光固化灯是牙科光固化复合树脂及黏结剂固化用的光源 ,其性能对复合树脂及黏结剂的固化有重要的影响。经过多年的发展 ,光固化灯的种类及性能有了很大进步 ,目前临床上应用的光固化灯有卤光灯、速效卤光灯、发光二极管灯、等离子弧光灯及氩激光灯。用以评价光固化灯的重要指标有光强、波长、光发热量、光源寿命、便携性等。光强又称亮度、功率密度 ,是光固化灯光出口单位面积每秒发射光子的数量 ,单位是mW/cm2 。根据输出光强度将光固化灯分为高亮度、中等亮度和低亮度 3个级别。高亮度光固化灯是指光强>1 0 0 0mW/cm2 ,中等亮度光固化灯的…     

发光二极管光固化灯的研究进展

随着光固化树脂的广泛应用,人们对光固化技术的研究也有了进一步的发展.传统的卤光灯因固有的缺陷限制了发展.本文介绍了发光二极管新型光固化灯的基本工作原理、特点及其发展,分析对比了发光二极管新型光固化灯与传统卤光灯对树脂物理性能、机械性能及生物学性能的影响,提出这种新型光固化技术亟待解决的问题,为其临床应用提供一定的理论依据.     

长春市口腔临床应用光固化灯的调查

目的调查长春市临床应用光固化灯的功率密度及其相关信息,为临床医师正确维护使用光固化灯提供参考。方法调查对象为长春市口腔专科医院、综合医院口腔科、民营诊所,采用简单随机抽样的方法,共检测270盏光固化灯的功率密度及相关信息,包括光固化灯的品牌、类型、使用年限、光导头数目及类型,光导头玷污、破损情况,使用频率,装置的检测及维修情况,灯数目/牙椅数。结果270盏光固化灯中,卤光灯174盏,发光二极管灯96盏,检测功率密度变化范围在0～1702 mW/cm2,平均功率密度为413.2 mW/cm2,73盏灯小于200 mW/cm2,不能充分聚合光固化复合树脂。光固化灯的平均使用年限为4.7年。大多数医师未检测过光固化灯的功率密度,84％(227/270)的光导头表面有树脂的玷污和破损。结论 长春市大部分光固化灯为卤光灯,部分灯老化明显,需要更新,大多数医师没有注意光固化灯需要定期检测和维修。     

老年口腔患者对两种光源固化灯临床应用的心理接受评价

目的:了解牙科发光二极管光固化灯和普通卤光灯应用于老年患者洞型树脂充填固化后,其心理接受的评价。方法:按纳入标准随机选择门诊就诊老年患者25例,共计患牙160颗(楔状缺损和龋损各80颗),患牙随机分为实验组和对照组。(去龋)备洞、隔湿、消毒,干燥,充填后,实验组采用发光二极管光固化灯固化,对照组采用普通卤光灯固化。所有患者在接受治疗后完成心理测试量表,量化对这2种不同光源固化灯的主观感受,并对结果进行统计学分析。结果:实验组总分233,平均9.32;对照组总分276,平均11.04,P<0.05,有统计学意义上的差异。患者对发光二极管光固化灯的牙科焦虑症程度较轻,心理接受度更好。结论:和普通卤光灯相比,老年患者对发光二极管光固化灯心理接受度高,牙科焦虑症程度较轻。     

光固化复合树脂固化程度的影响因素

影响光固化复合树脂固化程度的因素很多,本文就不同类型的光固化灯、复合树脂及临床操作等因素对光固化复合树脂固化程度的影响作一综述。     

光固化灯与光固化复合树脂

随着光固化修复在临床上广泛地应用,光固化灯也有了很快地发展。本文介绍了可见光固化灯的性能、光强度与光固化复合树脂固化深度的关系以及影响固化灯输出强度的因素。     

卤素和LED光固化灯照射复合树脂的机械强度比较

目的探讨3M2500型卤素光固化灯和3M FreeLight型LED光固化灯对光固化复合树脂机械强度及固化深度的影响。方法用WD-5A型电子拉力试验机、DUH-W201S型动态超显微硬度计2种仪器,通过测试比较卤素光固化灯和LED光固化灯照射Tetric ceram HB(Vivadent)A2色光固化复合树脂后其挠曲强度、压缩强度、表面硬度、固化深度的差异,从而比较3M2500型卤素光固化灯和3M FreeLight型LED光固化灯的性能。结果卤素光固化灯照射Tetric ceram HB复合树脂40s,LED光固化灯照射Tetric ceram HB10s,前者固化深度平均可达3.98mm,后者固化深度平均可达2.136mm,两者均可完全固化2mm,LED光固化灯固化树脂深度低于卤素光固化灯;表面硬度DHT115平均值分别为73.292MPa和39.668MPa,统计学分析95%水平有差别(P<0.05),LED灯对应的树脂硬度低于卤素灯;压缩强度平均值分别为242.1MPa和287.7MPa,统计学分析95%水平无明显差别(P>0.05);挠曲强度平均值分别为88.9MPa和97.0MPa,统计学分析95%水平无明显差别(P>0.05)。结论LED灯照射Tetric ceram HB复合树脂10s能达到卤素灯照射Tetric ceram HB复合树脂40s的聚合水平,适合于口腔临床应用。     

两种新型光固化灯与传统卤素灯照射复合树脂固化效果的比较

目的 探讨新型光固化灯Starlight S型LED光固化灯、DNX-TW-518型等离子弧光灯与传统的卤素光固化灯对Z100(3M,America)光固化复合树脂的固化深度和表面硬度的影响.方法 根据ISO 4049:2000标准.分别用两种新型光固化灯与传统卤素灯在标准条件下照射同一种复合树脂.检测其各自的固化深度和硬度.测试结果用SPSS软件进行方差分析和Dunnett-t检验,α=0.05.结果 卤素先固化灯照射Z100复合树脂40s组的平均固化深度可达3.760mm.高于LED光固化灯照射10s组的平均固化深彪.285mm(P<0.05);略高于LED光固化灯照射208组的平均固化深度3.693mm,但两者之同比较差别无统计学意义(P>0.05).等离子弧光灯照射3s组、5s组的平均固化深度分剐为1.984mm、2.575mm,均小于卤素灯照射40s组(P<0.05).而等离子孤光灯照射10s组的平均固化深度为4.387mm.高于卤素灯照射40s组(P灯20S组(55.309±4.472)GPa(P0.05).结论 不同光固化灯照射光敏复合树脂在相同条件下的固化深度和表面硬度不同.两种新型光固化灯田化复合树脂的潜力与卤素灯相似甚至有些方面胜于卤素灯.适合于口腔临床应用.     

影响光固化灯使用效率的相关因素

光固化复合树脂应用于口腔医学已有30多年的历史,而光固化灯作为复合树脂的照射光源对其性能及修复效果影响甚大。本文通过综述影响光固化灯使用效率的相关因素,为临床合理使用光固化灯提供理论依据和指导。     

口腔材料学教学实验课设计:光照条件对光固化复合树脂性能的影响

光固化复合树脂经光固化灯照射后固化,其临床性能在很大程度上受所用的光固化灯的影响,特别是光照强度和光照时间对其影响更为显着。为了帮助学生了解光照条件对光固化复合树脂性能的影响,北京大学口腔医学院在口腔材料学实验课教学中设计了两个实验:光固化复合树脂的固化深度实验和光固化复合树脂的挠曲强度实验。通过实验使学生掌握光照射时间和光照强度对光固化复合树脂固化深度和挠曲强度的影响规律。实验设计完成后,在2008级的八年制学生中进行了实际使用,并根据实验内容设计了调查问卷。问卷结果显示,实验课效果良好。     

Light curing--an update

Light-cured, resin-based composite is an integral part of esthetic and restorative dentistry. This article reviews the performance and limitations of 4 types of curing lights and predicts that curing lights of the future will use light-emitting diode (LED). Currently, LED curing lights are not as powerful as plasma arc curing (PAC) or quartz tungsten halogen (QTH) lights. For the present, QTH curing lights dominate, but PAC lights cure increments of composite resin more efficiently. This article discusses different curing lights: QTH lights, PAC lights, laser curing units, and LED curing lights. The support for different curing modes (soft, exponential, and pulse delay) to improve marginal integrity and reduce marginal leakage is examined.     

牙科发光二极管光固化灯和普通卤光灯临床应用效果评价

目的：了解牙科发光二极管光固化灯应用于患牙备洞树脂充填固化后的临床效果.方法：按纳入标准选择门诊就诊患者患牙160颗,龋损和楔状缺损各80颗.随机分为试验组和对照组,使用牙科树脂材料充填后,实验组应用发光二极管光固化灯固化20sec,对照组应用普通卤光灯固化40sec,打磨抛光;12个月后复诊,评价.结果：楔状缺损实验组有1颗充填物脱落,1颗边缘密合度缺陷,1颗边缘着色,成功率92.1%;对照组有1颗充填物脱落,1颗边缘着色,成功率94.4%;无统计学意义上的差异（P＞0.05）.龋损实验组有3例边缘密合度缺陷,2颗边缘着色,成功率87.5%;对照组有2颗边缘密合度缺陷,1颗边缘着色,成功率91.7%;无统计学意义上的差异（P＞0.05）.结论：发光二极管光固化灯与普通卤光灯临床效果没有区别,但操作时间更短,使用更为轻巧.     

Influence of different light sources on microleakage of class V composite resin restorations

The aim of this study was to evaluate the effect of three different curing units on microleakage of class V composite restorations. Class V cavities were prepared on the buccal surfaces of 45 extracted premolar teeth. The teeth were randomly divided into three groups of 15 each. A conventional halogen curing unit (Hilux 350), a high intensity halogen curing unit (Optilux 501) and plasma arc curing unit (Power Pac) were used to polymerize composite resin (Vitalesence). After restoration, the teeth were thermocycled for 100 cycles between 5 degrees and 55 degrees C using a dwell time of 30 s and exposed to a dye. Results showed that there was no significant difference among three different curing units (P > 0.05), however the microleakage at the dentin margins was greater than the enamel margins (P < 0.05). Clinical relevance: Plasma arc curing or fast halogen units cure composite materials at a faster rate than conventional curing units because of the high light intensity. High intensity halogen curing units and plasma arc curing units might be useful alternatives in composite polymerization. Therefore, these units are suggested for clinical use to save chair side time.     

Influence of light intensity from different curing units upon composite temperature rise

The unavoidable consequence of composite resin photopolymerization is temperature rise in tooth tissue. The temperature rise depends not only on the illumination time, but also on light intensity, distance of light guide tip from composite resin surface, composition and shade of composite resin and composite thickness. The most commonly used units for polymerization today are halogen curing units, which emit a large spectrum of wavelengths. A proportion of the spectrum has no influence on degree of conversion and therefore causes unnecessary temperature rise. Units based on light source - blue light emitting diodes (LED), as an alternative for halogen curing units, have been introduced in clinical practice. The aim of this study was to show the influence of the light intensity of curing units Elipar Trilight, Astralis 7 and Lux-o-Max unit on temperature rise in composite resin sample of Tetric Ceram. The temperature was measurement with Metex M-3850 D multimeter with the tip of temperature probe put into unpolymerized composite resin sample 1 mm depth. The highest temperature rise was recorded with standard curing mode for Elipar Trilight halogen curing unit (13.3 +/- 1.21 degrees C after 40 s illumination), while the lowest temperature rise was recorded for the Lux-o-Max unit based on LED technology (5.2 +/- 1.92 degrees C after 40 s illumination).     

Elution of TEGDMA and BisGMA from a resin and a resin composite cured with halogen or plasma light

Plasma arc light units for curing resin composites have been introduced with the claim of relatively short curing times. The purpose of the present study was to measure and compare elution of monomers from an experimental BisGMA-TEGDMA resin and a commercial resin composite when cured with a halogen unit and when cured with a plasma arc unit. Specimens of the materials were immersed in methanol, and the amounts of monomers released with time were analyzed by HPLC. By use of Fick's laws of diffusion, the amount of eluted monomers from the specimen at infinity was estimated. The elution from resin specimens and from resin composite specimens cured with the plasma arc light unit was 7 and 4 times higher, respectively, compared to the elution from specimens cured with the halogen unit. It was concluded that the plasma arc light curing unit did not provide optimal cure when used as recommended by the manufacturer.     

Depth of cure and surface microhardness of composite resin cured with blue LED curing lights.

OBJECTIVES: This study examined the depth of cure and surface microhardness of Filtek Z250 composite resin (3M-Espe) (shades B1, A3, and C4) when cured with three commercially available light emitting diode (LED) curing lights [E-light (GC), Elipar Freelight (3M-ESPE), 475H (RF Lab Systems)], compared with a high intensity quartz tungsten halogen (HQTH) light (Kerr Demetron Optilux 501) and a conventional quartz tungsten halogen (QTH) lamp (Sirona S1 dental unit). METHODS: The effects of light source and resin shade were evaluated as independent variables. Depth of cure after 40 s of exposure was determined using the ISO 4049:2000 method, and Vickers hardness determined at 1.0 mm intervals. RESULTS: HQTH and QTH lamps gave the greatest depth of cure. The three LED lights showed similar performances across all parameters, and each unit exceeded the ISO standard for depth of cure except GC ELight for shade B1. In terms of shade, LED lights gave greater curing depths with A3 shade, while QTH and HQTH lights gave greater curing depths with C4 shade. Hardness at the resin surface was not significantly different between LED and conventional curing lights, however, below the surface, hardness reduced more rapidly for the LED lights, especially at depths beyond 3 mm. SIGNIFICANCE: Since the performance of the three LED lights meets the ISO standard for depth of cure, these systems appear suitable for routine clinical application for resin curing.     

Effect of light source and time on the polymerization of resin cement through ceramic veneers

PURPOSE: The purpose of this study was to evaluate the efficiency of 3 different light sources to polymerize a light curing resin cement beneath 3 types of porcelain veneer materials. MATERIALS AND METHODS: A conventional halogen light, a plasma arc light, and a high intensity halogen light were used to polymerize resin cement (Variolink II; Ivoclar North America Inc, Amherst, NY) through disks of veneer materials. Equal diameter and thickness disks of feldspathic porcelain (Ceramco II; Ceramco Inc, Burlington, NJ), pressable ceramic (IPS Empress; Ivoclar North America Inc), and aluminous porcelain (Vitadur Alpha; Vident Inc, Brea, CA) were used as an interface between the curing light tips and the light polymerized resin cement. The resin cement/veneer combinations were exposed to 4 different photopolymerization time protocols of 5 seconds, 10 seconds, 15 seconds, and 20 seconds for high intensity light units (Apollo 95E [Dental Medical Diagnostic Systems Inc, Westlake Village, CA] and Kreativ 2000 [Kreativ Inc, San Diego, CA]), and 20 seconds, 40 seconds, 60 seconds, and 80 seconds for conventional halogen light (Optilux; Demetron Research Inc, Danbury, CT). A surface hardness test (Knoop indenter) was used to determine the level of photopolymerization of the resin through the ceramic materials with each of the light sources. The data were analyzed by one-way analysis of variance and a post-hoc Scheffe test (p < .05). RESULTS: The data indicates that the Variolink II Knoop Hardness Number values vary with the light source, the veneer material, and the polymerization time. For a given light and veneer material, Knoop Hardness Number increases with longer polymerization times. The Kreativ light showed statistically significant differences (p < .05) between all test polymerization times. Use of this light required a polymerization time of greater than 20 seconds to reach maximum resin cement hardness. For samples polymerized with the Apollo light, there were statistically significant (p < .05) differences in surface hardness between samples polymerized at all times, except for the 15-second and 20-second times. Samples polymerized with the halogen light showed no statistically significant (p < .05) differences in hardness between polymerization times of 60 seconds and 80 seconds. CONCLUSIONS: High intensity curing lights achieve adequate polymerization of resin cements through veneers in a markedly shorter time period than the conventional halogen light. However, the data in this report indicate that a minimum exposure time of 15 seconds with the Kreativ light and 10 seconds with the Apollo 95E light should be used to polymerize the Variolink II resin, regardless of the composition of the veneer. Conventional halogen lights required a correspondingly greater polymerization time of 60 seconds.     

Pulpal heat changes with newly developed resin photopolymerisation systems

Composite resin is a widely-used direct tooth coloured restorative material. Photoactivation of the polymerisation reaction can be achieved by visible blue light from a range of light sources, including halogen lamps, metal halide lamps, plasma arc lamps, and Light Emitting Diode (LED) lights. Concerns have been raised that curing lights may induce a temperature rise that could be detrimental to the vitality of the dental pulp during the act of photoactivation. The present study examined heat changes associated with standardised class V restorations on the buccal surface of extracted premolar teeth, using a curing time of 40 seconds. The independent effects of type of light source, resin shade, and remaining tooth thickness were assessed using a matrix experimental design. When a conventional halogen lamp, a metal halide lamp and two different LED lights were compared, it was found that both LED lamps elicited minimal thermal changes at the level of the dental pulp, whereas the halogen lamp induced greater changes, and the metal halide lamp caused the greatest thermal insult of all the light sources. These thermal changes were influenced by resin shade, with different patterns for LED versus halogen or halide sources. Thermal stress reduced as the remaining thickness of tooth structure between the pulp and the cavity floor increased. From these results, it is concluded that LED lights produce the least thermal insult during photopolymerisation of composite resins.     

Light-emitting diode curing: influence on selected properties of resin composites.

OBJECTIVE: Two recently marketed light-emitting diode polymerization units were compared with a conventional halogen curing unit. Selected properties of resin composites polymerized with the three curing units were determined. METHOD AND MATERIALS: Three different brands of resin composite were used in the investigation. The properties that were determined were flexural strength and modulus, determined in three-point bending tests; depth of polymerization, assessed by removal of uncured material after irradiation; polymerization contraction, evaluated with the bonded-disk method; and degree of conversion, measured by Fourier transform infrared spectroscopy. RESULTS: The properties of resin composites polymerized with light-emitting diode curing units were equal or inferior to properties obtained after halogen light curing. CONCLUSION: Although several properties with some combinations of resin composite and light-emitting diode curing unit were inferior to properties obtained with the halogen curing unit, both the flexural strength and the depth of polymerization fulfilled the requirements set by the International Standards Organization.     

The Knoop hardness of a composite resin polymerized with different curing lights and different modes

AIM: The purpose of this study was to compare the surface hardness of a hybrid composite resin polymerized with different curing lights. METHODS AND MATERIALS: Two 3.0 mm thick composite resin discs were polymerized in a prepared natural tooth mold using: (1) a conventional quartz-tungsten halogen light (QTH- Spectrum 800); (2) a high-intensity halogen light, Elipar Trilight (TL)-standard/exponential mode; (3) a high-intensity halogen light, Elipar Highlight (HL)-standard/soft-start mode; (4) a light-emitting diode, Elipar Freelight (LED); and (5) a plasma-arc curing light, Virtuoso (PAC). Exposure times were 40 seconds for the halogen and LED lights, and three and five seconds for the PAC light. Following polymerization, the Knoop hardness was measured at the bottom and the top surfaces of the discs. RESULTS: Significant differences were found between top and bottom Knoop Hardness number (KHN) values for all lights. The hardness of the top and bottom surfaces of both specimens cured by the PAC light was significantly lower than the other lights. No significant hardness differences were observed between the remaining curing units at the top of the 2.0 mm specimens. Significant differences were found between the LED and two modes of HL on the bottom surfaces. For the 3.0 mm thick samples, while significant differences were noted between LED and TL standard mode and between the two TL curing modes on the top, significant differences were only observed between QTH and the standard modes of TL and HL at the bottom.