Halogen and LED light curing of composite: temperature increase and Knoop hardness

Abstract Aim The purpose of this study was to evaluate the effectiveness of three commercially available light emitting diode (LED) light curing units (LCU) (Elipar FreeLight - 3M ESPE; UltraLume LED2 - Ultradent; and Single V - BioArt) for polymerizing Z250-A3 composite (3M ESPE) using Knoop hardness, polymerization depth, and flexural strength properties. Methods and Materials The XL 2500 (3M ESPE) LCU, which is a conventional halogen unit, was used as a control. In all cases the curing time was 20 seconds. Hardness was determined 24 hours after composite cure for 10 samples of 8 mm diameter and 2 mm height for each LCU tested. Samples were stored dry in a lightproof container prior to testing. The depth of cure of the composite was measured immediately after composite polymerization for each LCU using three samples 4 mm in diameter and 6 mm in height. Flexural strength was determined for five samples 24 hours after immersion in distilled water at 37°C. Each sample measured 25 mm in length, 2 mm in width, and 2 mm in height for each LCU tested. Conclusion The results were treated statistically for comparison of the LCUs. In all cases the results obtained by LED LCUs were not different or were higher than a conventional halogen LCU. Clinical Significance Second generation LED LCUs were as effective as/or more effective than a halogen LCU for polymerization of the used composite. The present study shows second generation LEDs have the potential to replace halogen LCUs. Citation Campregher UB, Samuel SMW, Fortes CBB, Medina ADC, Collares FMC, Ogliari FA. Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units. J Contemp Dent Pract 2007 February;(8)2:035-042.

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Analysis of the Effect of Dental Chair Light on the Knoop Hardness of Composite Resin While Light Curing with QTH and LED Light Units

World Journal of Dentistry ◽

10.5005/jp-journals-10015-1148 ◽

2012 ◽

Vol 3 (2) ◽

pp. 156-160

Author(s):

Bandish Parekh ◽

Sucheta Sathe

Keyword(s):

Composite Resin ◽

Light Emitting Diode ◽

Hardness Test ◽

Knoop Hardness ◽

Degree Of Polymerization ◽

Led Light ◽

Group Iii ◽

Dental Chair ◽

Group I ◽

Light Curing

ABSTRACT Dental chair lights have been known to rapidly polymerize lightcured composites beyond the point of workability. Often in our dental clinics we are advised to switch off the dental chair light while light curing of dental composites. The purpose of this study was to determine whether the dental chair light causes any effect on the degree of polymerization of light cured composites using the quartz tungsten halogen (QTH) and the light emitting diode (LED) light curing units (LCUs). Filtek Z350 composite samples of 2 × 5 mm were prepared in an acrylic mold. Four groups were made having 20 samples each. In group I and II light curing was done using QTH LCU with and without the dental chair light respectively. Similarly in group III and IV LED LCU was used. Microhardness was measured and compared using Knoop's hardness Test. Data was submitted to ANOVA and Tukey's test. Results showed that the average microhardness was significantly higher in group 4 (LED light curing with dental chair light on). Thus, it was concluded that the dental chair light can be left on while using QTH and LED LCU's during light curing of composite material. How to cite this article Parekh B, Sathe S, Hegde V. Analysis of the Effect of Dental Chair Light on the Knoop Hardness of Composite Resin While Light Curing with QTH and LED Light Units. World J Dent 2012;3(2):156-160.

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Photoinitiator dependent composite depth of cure and Knoop hardness with halogen and LED light curing units

Biomaterials ◽

10.1016/s0142-9612(02)00532-x ◽

2003 ◽

Vol 24 (10) ◽

pp. 1787-1795 ◽

Cited By ~ 70

Author(s):

Alexander Uhl ◽

Robin W. Mills ◽

Klaus D. Jandt

Keyword(s):

Knoop Hardness ◽

Led Light ◽

Depth Of Cure ◽

Light Curing

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Does an additional UV LED improve the degree of conversion and Knoop Hardness of light-shade composite resins?

European Journal of Dentistry ◽

10.1055/s-0039-1698978 ◽

2012 ◽

Vol 06 (04) ◽

pp. 396-401 ◽

Cited By ~ 1

Author(s):

Maria Cecília Caldas Giorgi ◽

Flávio Henrique Baggio Aguiar ◽

Luís Luís Soares ◽

Airton Abrahão Martin ◽

Priscila Christiane Suzy Liporoni ◽

...

Keyword(s):

Knoop Hardness ◽

Surface Interaction ◽

Composite Resins ◽

Degree Of Conversion ◽

Third Generation ◽

Composite Surface ◽

Led Light ◽

Uv Led ◽

Significant Difference ◽

Light Curing

ABSTRACTObjective: The purpose of this study was to evaluate the degree of conversion (DC) using FTRaman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5.Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces. For DC (n=10), both the T and B surfaces were analyzed.Results: For KHN, the three composites differed in hardens. There was a “LCU-surface” interaction, in which Radii Cal showed significantly greater hardens in the B surface. For DC, there was a “composite-surface-LCU” interaction. For the “composite” factor, there was no significant difference between the groups, except for Supreme XT-Radii Cal (T or B surfaces). For the “LCU” factor there was a significant difference for Supreme XT T surface, Ultralume 5 obtained a higher DC. For the Z350 T surface, a significant difference in the DC in which Radii Cal obtained better results. For the “surface” factor, all groups presented T surfaces with a higher DC than the B surfaces, the sole exceptions involved Esthet X-Radii Cal and Z350-Ultralume 5.Conclusion: Knowledge regarding composite composition and the characteristics of LCUs are important for effective polymerization. (Eur J Dent 2012;6:396-401)

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Knoop hardness depth profiles and compressive strength of selected dental composites polymerized with halogen and LED light curing technologies

Journal of Biomedical Materials Research ◽

10.1002/jbm.b.1001 ◽

2003 ◽

Vol 64B (2) ◽

pp. 130-131

Keyword(s):

Compressive Strength ◽

Knoop Hardness ◽

Dental Composites ◽

Led Light ◽

Depth Profiles ◽

Light Curing ◽

Hardness Depth

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Analysis of temperature increase in swine gingiva after exposure to a Polywave ® LED light curing unit

Dental Materials ◽

10.1016/j.dental.2017.07.021 ◽

2017 ◽

Vol 33 (11) ◽

pp. 1266-1273 ◽

Cited By ~ 4

Author(s):

Cristiane Maucoski ◽

Driellen Christine Zarpellon ◽

Fabio Andre dos Santos ◽

Leandro Cavalcante Lipinski ◽

Eduardo Bauml Campagnoli ◽

...

Keyword(s):

Temperature Increase ◽

Led Light ◽

Light Curing

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Effect of LED Light-Curing Spectral Emission Profile on Light-Cured Resin Cement Degree of Conversion

Operative Dentistry ◽

10.2341/19-234-l ◽

2020 ◽

Author(s):

RQ Ramos ◽

RR Moraes ◽

GC Lopes

Keyword(s):

Clinical Relevance ◽

Degree Of Conversion ◽

Resin Cement ◽

Light Activation ◽

Spectral Emission ◽

Led Light ◽

Emission Profile ◽

Light Curing

Clinical Relevance The use of multipeak LED light-curing guarantees efficiency on light activation of Ivocerin-containing light-cured resin cement.

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An Evaluation of the Efficacy of LED Light Curing Units in Primary and Secondary Dental Settings in the United Kingdom

Operative Dentistry ◽

10.2341/20-092-lit ◽

2021 ◽

Author(s):

A Altaie ◽

MA Hadis ◽

V Wilson ◽

MJ German ◽

BR Nattress ◽

...

Keyword(s):

Light Output ◽

Led Light ◽

The United Kingdom ◽

Dental Practices ◽

Light Curing ◽

Blue Phase ◽

And Performance ◽

The Uk ◽

Post Hoc

SUMMARY Objective: This study aimed to evaluate the irradiance and the quality of LED light curing units (LCUs) in primary and secondary clinics in the UK and to assess the effect of damage, contamination, use of protective sleeves, and distance of light tips to target on the irradiance and performance of LCUs. Methods: The irradiance levels (mW/cm2) of 26 LED LCUs from general dental practices and 207 LED LCUs from two dental hospitals were measured using a digital radiometer (Blue Phase II, Ivoclar, Vivadent, Amherst, NY). Ten LED light guide tips (Satelec Mini, Acteon, Merignac, France) were selected to evaluate the effect of chipping, contamination (tip debris), and use of protective sleeves and tips to sensor distance on irradiance (mW/cm2) using a MARC Resin Calibrator (Blue Light Analytics, Halifax, Canada). Homogeneity of the light output was evaluated using a laser beam profiler (SP620; Ophir-Spiricon, North Longan, UT, USA). Statistical analysis was conducted using a one-way analysis of variance (ANOVA) with post hoc Tukey test (α=0.05) and linear regression with stepwise correlation tests. Results: Thirty-three percent of the LCUs delivered irradiance output less than 500 mW/cm2. The condition of the light curing tips was poor, with 16% contaminated with resin debris, 26% damaged, and 10% both contaminated and damaged. The irradiance output was significantly reduced in contaminated (62%) and chipped (50%) light curing tips and when using protective sleeves (24%) (p<0.05). Irradiance was also reduced when increasing the distance with 25% and 34% reduction at 7 mm and 10 mm, respectively (p<0.05). Conclusion: There remains a lack of awareness of the need for regular monitoring and maintenance of dental LCUs. Damaged and contaminated light curing tips, use of protective sleeves, and increasing the distance from the restoration significantly reduced the irradiance output and the performance of the LCUs.

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