A study on the degree of conversion of light curing composite resin according to the thickness of tooth structure penetrated by light and applied light curing time

2002 ◽  
Vol 27 (1) ◽  
pp. 16 ◽  
Author(s):  
Kee-Hwan Hwang ◽  
In-Ho Jang ◽  
Se-Joon Lee ◽  
Kwang-Won Lee
Keyword(s):  
Composite Resin ◽  
Degree Of Conversion ◽  
Curing Time ◽  
Tooth Structure ◽  
Light Curing

scholarly journals Effects of delivering the same radiant exposures at 730, 1450, and 2920 mW/cm2 to two resin-based composites

2017 ◽  
Vol 11 (01) ◽  
pp. 022-028 ◽  
Author(s):  
Maan M. AlShaafi
Keyword(s):  
Fourier Transform ◽  
Degree Of Conversion ◽  
Attenuated Total Reflectance ◽  
Curing Time ◽  
Total Reflectance ◽  
Metal Rings ◽  
Significant Difference ◽  
Light Curing ◽  
Knoop Microhardness ◽  
Different Depths

ABSTRACT Objective: To evaluate the effects of curing two resin-based composites (RBC) with the same radiant exposures at 730, 1450, and 2920 mW/cm2. Materials and Methods: Two types of RBC, Filtek Supreme Ultra and Tetric-EvoCeram-Bulk Fill, were light-cured to deliver the same radiant exposures for 5, 10, or 20 s by means of a modified Valo light emitted diode light-curing unit with the light tip placed directly over each specimen. The RBC was expressed into metal rings that were 2.0 and 4.0 mm in thickness, directly on an attenuated total reflectance Fourier transform infrared plate heated to 33°C, and the degree of conversion (DC) of the RBC was recorded. The specimens were then removed and the Knoop microhardness (KHN) was tested at both the bottom and the top of each specimen. The KHN was tested again after 24 h and 7 days of storage in the dark at 37°C and 100% humidity. The DC and KHN results were analyzed with Fisher's protected least significant difference at α = 0.05. Results: The DC values for the specimens cured at the three different irradiance levels were similar. However, at different depths, there were differences in the DC values. In general, there were no clear differences among the samples cured in the three different groups, and the KHN was always greater 24 h and 7 days later (P < 0.05). Conclusions: Despite the curing time, and as long as the samples were cured with the same radiant exposures, there were no significant effects on the DC and KHN of both RBCs.

Split-increment Technique: An Alternative Approach for Large Cervical Composite Resin Restorations

2007 ◽  
Vol 8 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Khamis A. Hassan ◽  
Salwa E. Khier
Keyword(s):  
Composite Resin ◽  
Root Surface ◽  
Tooth Structure ◽  
Carious Lesions ◽  
Alternative Approach ◽  
Light Curing ◽  
Composite Resin Restorations ◽  
Natural Tooth ◽  
Made In ◽  
Resin Restorations

Abstract Aim This article proposes and describes the split-increment technique as an alternative for placement of composite resin in large cervical carious lesions which extend onto the root surface. Technique Two flat 1.5 mm thick composite resin increments were used to restore these cervical carious lesions. Prior to light-curing, two diagonal cuts were made in each increment in order to split it into four triangular-shaped flat portions. The first increment was applied to cover the entire axial wall and portions of the four surrounding walls. The second increment was applied to fill the cavity completely covering the first one and the rest of the four surrounding walls as well as sealing all cavity margins. Clinical Significance This technique results in the reduction of the C-factor and the generated shrinkage stresses by directing the shrinking composite resin during curing towards the free, unbonded areas created by the two diagonal cuts. The proposed technique would also produce a more naturally looking restoration by inserting flat dentin and enamel increments of composite resin of a uniform thickness which closely resembles the arrangement of natural tooth structure. Citation Hassan KA, Khier SE. Split-increment Technique: An Alternative Approach for Large Cervical Composite Resin Restorations. J Contemp Dent Pract 2007 February;(8)2:121-128.

scholarly journals Impact of Solvent Evaporation and Curing Protocol on Degree of Conversion of Etch-and-Rinse and Multimode Adhesives Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Ceci Nunes Carvalho ◽  
Marcos Daniel Septímio Lanza ◽  
Letícia Gomes Dourado ◽  
Edilausson Moreno Carvalho ◽  
José Bauer
Keyword(s):  
Solvent Evaporation ◽  
Degree Of Conversion ◽  
Curing Time ◽  
Light Activation ◽  
Adhesive Systems ◽  
Air Drying ◽  
Air Stream ◽  
Etch And Rinse ◽  
Light Curing ◽  
One Step

Objectives. This study evaluated the effect of air-drying time and light-curing time on the degree of conversion (DC) of three etch-and-rinse adhesive systems: ONE-STEP (OS) and ONE-STEP plus (OSP), Ambar (AMB), and two multimode adhesive systems: All-Bond Universal (ABU) and ScotchBond Universal (SBU) by Fourier transform infrared (FTIR) analysis. Materials and Methods. The DC of each adhesive system was analyzed with six experimental different protocols: (1) immediate light curing for 10 s without solvent volatilization; (2) 10 s solvent volatilization with air stream plus 10 s light curing; (3) 60 s solvent volatilization with air stream plus 10 s light curing; (4) immediate light curing for 20 s without solvent volatilization; (5) 10 s solvent volatilization with air stream plus 20 s light curing; and (6) 60 s solvent volatilization with air stream plus 20 s light curing. FTIR spectra were obtained, and the DC was calculated by comparing the ratio of aliphatic/aromatic double carbon bonds before and after light activation (Bluephase 20i). The DC means were analyzed by three-way analysis of variance (ANOVA) and post hoc Tukey tests (α = 0.05). Results. Three-way ANOVA showed statistically significant adhesive, air-drying, and light-cured time (p<0.001). In general, there was a trend of increased DC when the adhesives were dried and cured for longer times, but that was not observed for all the adhesives tested. The acetone-based adhesive systems require an air-drying prior to light activation. The light-curing time of 20 s increases the DC of all materials tested. Conclusion. The results suggested that the DC of the adhesive systems tested was material dependent. In general, the protocol with solvent evaporation for 10 seconds with air syringe plus 20 seconds of light curing finds the high values of DC.

scholarly journals Effect of LED and Argon Laser on Degree of Conversion and Temperature Rise of Hybrid and Low Shrinkage Composite Resins

2016 ◽  
Vol 10 (1) ◽  
pp. 538-545 ◽  
Author(s):  
Ayob Pahlevan ◽  
Masumeh Hasani Tabatabaei ◽  
Sakineh Arami ◽  
Sara Valizadeh
Keyword(s):  
Energy Density ◽  
Temperature Rise ◽  
Composite Resin ◽  
Argon Laser ◽  
Composite Resins ◽  
Degree Of Conversion ◽  
Light Curing ◽  
Higher Temperature ◽  
Laser Curing ◽  
One Way Anova

Objectives:Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights.Materials and Methods:DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance).Results:The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units.Conclusion:Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.

scholarly journals Impact of the light-curing source and curing time on the degree of conversion and hardness of a composite

2013 ◽  
Vol 1 (1) ◽  
pp. 91
Author(s):  
Anderson Catelan ◽  
Caetano Tamires ◽  
Boniek Castillo Dutra Borges ◽  
Giulliana Panfiglio Soares ◽  
Bruno de Castro Ferreira Barreto ◽  
...  
Keyword(s):  
Physical Properties ◽  
Light Emitting Diode ◽  
Knoop Hardness ◽  
High Irradiance ◽  
Degree Of Conversion ◽  
Curing Time ◽  
Light Emitting ◽  
Light Curing ◽  
Ft Ir ◽  
The Impact

Adequate physical properties of the resinous materials are related to clinical longevity of adhesive restorations. The aim of this investigation was to assess the impact of light-curing source and curing time on the degree of conversion (DC) and Knoop hardness number (KHN) of a composite resin. Circular specimens (5 x 2 mm) were carried out (n = 7) of the Filtek Z250 (3M ESPE) composite. The specimens were light-cured by quartz-halogen-tungsten (QTH) XL 3000 (3M ESPE, 450 mW/cm2) or light-emitting diode (LED) Bluephase 16i (Vivadent, 1390 mW/cm2) for 20, 40, or 60 s. After 24 h, absorption spectra of composite were obtained using Spectrum 100 Optica (Perkin Elmer) FT-IR spectrometer in order to calculate the DC and, KHN was performed in the HMV-2T (Shimadzu) microhardness tester under 50-g load for 15 s dwell time. DC and KHN data were subjected to 2-way ANOVA and Tukey’s test at a pre-set alpha of 0.05. The LED showed highest DC and KHN values than QTH (p < 0.05). The increase of curing time improved the DC and KHN, all curing times with statistical difference (p < 0.05). The use of light-curing units with high irradiance and/or the time of cure increased may improve the physical properties of resin-based materials.

scholarly journals Effect of Different LED Light-curing Units on Degree of Conversion and Microhardness of Bulk-fill Composite Resin

2020 ◽  
Vol 21 (6) ◽  
pp. 615-620
Author(s):  
Trimurni Abidin ◽  
Dennis Dennis ◽  
Juliana S Siagian ◽  
Tulus Ikhsan
Keyword(s):  
Composite Resin ◽  
Degree Of Conversion ◽  
Led Light ◽  
Light Curing

scholarly journals Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

2010 ◽  
Vol 18 (5) ◽  
pp. 461-466 ◽  
Author(s):  
Andreza Maria Fábio Aranha ◽  
Elisa Maria Aparecida Giro ◽  
Josimeri Hebling ◽  
Fernanda Campos Rosetti Lessa ◽  
Carlos Alberto de Souza Costa
Keyword(s):  
Composite Resin ◽  
Curing Time ◽  
Light Curing

Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin

2007 ◽  
Vol 8 (6) ◽  
pp. 1-8 ◽  
Author(s):  
José Roberto Lovadino ◽  
Gláucia Maria Bovi Ambrosano ◽  
Flávio Henrique Baggio Aguiar ◽  
Aline Braceiro ◽  
Débora Alves Nunes Leite Lima
Keyword(s):  
Hybrid Composite ◽  
High Intensity ◽  
Composite Resin ◽  
Resin Composite ◽  
Composite Resins ◽  
Bottom Surface ◽  
Curing Time ◽  
Experimental Conditions ◽  
Light Curing ◽  
Effect Of Light

Abstract Aims The aim of this in vitro study was to evaluate the influence of light curing modes and curing time on the microhardness of a hybrid composite resin. Methods and Materials Forty-five Z250 composite resin specimens (3M-ESPE Dental Products, St. Paul, MN, USA) were randomly divided into nine groups (n=5): three polymerization modes (conventional - 550 mW/ cm2; light-emitting diodes (LED) - 360mW/cm2, and high intensity - 1160 mW/cm2) and three light curing times (once, twice, and three times the manufacturer's recommendations). All samples were polymerized with the light tip 8 mm from the specimen. Knoop microhardness measurements were obtained on the top and bottom surfaces of the sample. Results Conventional and LED polymerization modes resulted in higher hardness means and were statistically different from the high intensity mode in almost all experimental conditions. Tripling manufacturers’ recommended light curing times resulted in higher hardness means; this was statistically different from the other times for all polymerization modes in the bottom surface of specimens. This was also true of the top surface of specimens cured using the high intensity mode but not of conventional and LED modes using any of the chosen curing times. Top surfaces showed higher hardness than bottom surfaces. Conclusions It is important to increase the light curing time and use appropriate light curing devices to polymerize resin composite in deep cavities to maximize the hardness of hybrid composite resins. Citation Aguiar FHB, Braceiro A, Lima DANL, Ambrosano GMB, Lovadino JR. Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin. J Contemp Dent Pract 2007 September; (8)6:001-008.

Sign in / Sign up

Export Citation Format

Share Document