scholarly journals The effect of light curing units, curing time, and veneering materials on resin cement microhardness

2013 ◽  
Vol 8 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Nurcan Ozakar Ilday ◽  
Yusuf Ziya Bayindir ◽  
Funda Bayindir ◽  
Aysel Gurpinar
Keyword(s):  
Resin Cement ◽  
Curing Time ◽  
Light Curing ◽  
Effect Of Light

scholarly journals Effect of Light-Sources and Thicknesses of Composite Onlays on Micro-Hardness of Luting Composites

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6849
Author(s):  
Francesco De Angelis ◽  
Mirco Vadini ◽  
Mario Capogreco ◽  
Camillo D’Arcangelo ◽  
Maurizio D’Amario
Keyword(s):  
High Power ◽  
Resin Composite ◽  
Composite Layer ◽  
Resin Cement ◽  
Specimen Thickness ◽  
Light Sources ◽  
Curing Time ◽  
Resin Cements ◽  
Halogen Light ◽  
Light Curing

The aim of this study was to compare three different light-curing-units (LCUs) and determine their effectiveness in the adhesive cementation of indirect composite restorations when a light-curing resin cement is used. Two resin composites were selected: Enamel Plus HRI (Micerium) and AURA (SDI). Three thicknesses (3 mm, 4 mm and 5 mm) were produced and applied as overlays and underlays for each resin composite. A standardized composite layer was placed between underlay and overlay surfaces. Light curing of the resin-based luting composites was attained through the overlay filters using LCUs for different exposure times. All specimens were allocated to experimental groups according to the overlay thickness, curing unit and curing time. Vickers Hardness (VH) notches were carried out on each specimen. Data were statistically evaluated. The curing unit, curing time and overlay thickness were significant factors capable of influencing VH values. The results showed significantly decreased VH values with increasing specimen thickness (p < 0.05). Significant differences in VH values were found amongst the LCUs for the various exposure times (p < 0.05). According to the results, a time of cure shorter than 80 s (with a conventional quartz–tungsten–halogen LCU) or shorter than 40 s (with a high-power light-emitting diode (LED) LCU) is not recommended. The only subgroup achieving clinically acceptable VH values after a short 20 s curing time included the 3 mm-thick overlays made out of the AURA composite, when the high-power LED LCU unit was used (VH 51.0). Composite thickness has an intense effect on polymerization. In clinical practice, light-cured resin cements may result in insufficient polymerization for high thickness and inadequate times. High-intensity curing lights can attain the sufficient polymerization of resin cements through overlays in a significantly shorter time than conventional halogen light.

scholarly journals In Vitro Cytotoxicity of Self-Adhesive Dual-Cured Resin Cement Polymerized Beneath Three Different Cusp Inclinations of Zirconia

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Chang-Yuan Zhang ◽  
Yi-Ling Cheng ◽  
Xin-Wen Tong ◽  
Hao Yu ◽  
Hui Cheng
Keyword(s):  
In Vitro Cytotoxicity ◽  
Resin Cement ◽  
Curing Time ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Extract Solution ◽  
Significant Difference ◽  
Light Curing ◽  
Post Hoc

The aim of the present study was to evaluate the in vitro cytotoxicity of self-adhesive dual-cured resin cement (SADRC) polymerized beneath three different cusp inclinations of zirconia with different light curing time. A commercial SADRC (Multilink Speed) was polymerized beneath zirconia (ZrO2) with three different cusp inclinations (0°, 20°, and 30°) for 20 s or 40 s. After being stored in light-proof box for 24 h, the ZrO2-SADRC specimens were immersed in DMEM for 72 h and then we got the extract solution, cultured the human gingival fibroblasts (HGF, 8 × 103 per well) with 100% or 50% concentrations of the extract solution for 24 h, 72 h, and 120 h, respectively, and evaluated cytotoxicity of the polymerized SADRC with CCK-8 assay in optical density (OD) values, relative growth rates (RGR), and cytotoxicity grades. Statistical analysis was conducted using a two-way ANOVA followed by post hoc Student–Newman–Keuls test. The OD values varied from 0.8930 to 3.2920, the RGR varied from 33.93% to 98.68%, and the cytotoxicity grades varied from 0 to 2. There was significant difference in the OD values among the different cusp inclinations of zirconia (P < 0.001), and there was significant difference in the OD values between the different light curing times in some situations (P < 0.05). The cusp inclination of zirconia affects the in vitro cytotoxicity of SADRC. Prolonging the light curing time from 20 s to 40 s can reduce the in vitro cytotoxicity of SADRC when the cusp inclination of zirconia is smaller than 20°.

Diode-pumped solid-state laser for bonding orthodontic brackets: effect of light intensity and light-curing time

2010 ◽  
Vol 26 (5) ◽  
pp. 585-589 ◽  
Author(s):  
Young-Oh Kim ◽  
Soo-Byung Park ◽  
Woo-Sung Son ◽  
Ching-Chang Ko ◽  
Franklin García-Godoy ◽  
...  
Keyword(s):  
Solid State ◽  
Light Intensity ◽  
Solid State Laser ◽  
Orthodontic Brackets ◽  
Curing Time ◽  
State Laser ◽  
Light Curing ◽  
Diode Pumped ◽  
Effect Of Light

Effect of Light-Curing Method and Cement Activation Mode on Resin Cement Knoop Hardness

2007 ◽  
Vol 16 (6) ◽  
pp. 480-484 ◽  
Author(s):  
Rubens Nisie Tango ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Américo Bortolazzo Correr ◽  
Lourenço Correr-Sobrinho ◽  
Guilherme Elias Peçanha Henriques
Keyword(s):  
Knoop Hardness ◽  
Resin Cement ◽  
Light Curing ◽  
Curing Method ◽  
Effect Of Light

Effect of Light Energy Density on Conversion Degree and Hardness of Dual-cured Resin Cement

2010 ◽  
Vol 35 (1) ◽  
pp. 120-124 ◽  
Author(s):  
P. C. P. Komori ◽  
A. B. Paula ◽  
A. A. Martin ◽  
R. N. Tango ◽  
M. A. C. Sinhoreti ◽  
...  
Keyword(s):  
Energy Density ◽  
Physical Properties ◽  
Clinical Relevance ◽  
Light Energy ◽  
Resin Cement ◽  
Conversion Degree ◽  
Light Curing ◽  
Effect Of Light

Clinical Relevance Light energy density can influence the curing of dual-cured resin cement. The ultimate physical properties of dual-cured resin cement depend on light energy delivered from the light-curing unit. It can guide the clinicians to select the appropriate curing unit for curing dual cement.

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.

scholarly journals Effect of light-curing units, post-cured time and shade of resin cement on knoop hardness

2009 ◽  
Vol 20 (5) ◽  
pp. 410-413 ◽  
Author(s):  
Rogério Vieira Reges ◽  
Ana Rosa Costa ◽  
Américo Bortolazzo Correr ◽  
Evandro Piva ◽  
Regina Maria Puppin-Rontani ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Knoop Hardness ◽  
Resin Cement ◽  
Light Emitting ◽  
Ceramic Disc ◽  
Quartz Tungsten Halogen ◽  
Cure Time ◽  
Light Curing ◽  
Effect Of Light ◽  
Made In

The aim of this study was to evaluate the Knoop hardness after 15 min and 24 h of different shades of a dual-cured resin-based cement after indirect photoactivation (ceramic restoration) with 2 light-curing units (LCUs). The resin cement Variolink II (Ivoclar Vivadent) shade XL, A2, A3 and opaque were mixed with the catalyst paste and inserted into a black Teflon mold (5 mm diameter x 1 mm high). A transparent strip was placed over the mold and a ceramic disc (Duceram Plus, shade A3) was positioned over the resin cement. Light-activation was performed through the ceramic for 40 s using quartz-tungsten-halogen (QTH) (XL 2500; 3M ESPE) or light-emitting diode (LED) (Ultrablue Is, DMC) LCUs with power density of 615 and 610 mW/cm2, respectively. The Koop hardness was measured using a microhardness tester HMV 2 (Shimadzu) after 15 min or 24 h. Four indentations were made in each specimen. Data were subjected to ANOVA and Tukey's test (a=0.05). The QTH LCU provided significantly higher (p<0.05) KHN values than the LED LCU. When the post-cure times were compared for the same shade, QTH and LED at 24 h provided significantly higher (p<0.05) KHN values than at 15 min. It may be concluded that the Knoop hardness was generally dependent on the LCU and post-cure time. The opaque shade of the resin cement showed lower Knoop hardness than the other shades for both LCUs and post-cure times.

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