Effect of Shortened Light-Curing Modes on Bulk-Fill Resin Composites

2020 ◽  
Vol 45 (5) ◽  
pp. 496-505
Author(s):  
CS Sampaio ◽  
PG Pizarro ◽  
PJ Atria ◽  
R Hirata ◽  
M Giannini ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Light Output ◽  
High Mode ◽  
Resin Composites ◽  
Curing Time ◽  
Micro Computed Tomography ◽  
Polymerization Shrinkage ◽  
Light Curing

Clinical Relevance Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro–computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS. Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes. Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.

scholarly journals A Modified Photoactivation Protocol Using Two Simultaneous Light-Curing Units for Bonding Brackets to Enamel

2015 ◽  
Vol 26 (4) ◽  
pp. 393-397 ◽  
Author(s):  
Adauê Siegert de Oliveira ◽  
Rafael Correa Mirapalhete ◽  
Cássia Cardozo Amaral ◽  
Rafael Ratto de Moraes
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Curing Time ◽  
Thermal Cycles ◽  
Adhesive Remnant Index ◽  
Light Curing ◽  
Standard Deviations ◽  
Curing Method

<p>This study investigated the effect of a modified photoactivation protocol using two simultaneous light-curing units on the shear bond strength (SBS) of brackets to enamel. Metal brackets were bonded to bovine incisors using the resin-based orthodontic cement Transbond XT (3M Unitek). Four photoactivation protocols of the orthodontic cement were tested (n=15): Control: photoactivation for 10 s on each proximal face of the bracket at a time; Simultaneous: photoactivation for 10 s on both proximal faces of the bracket at the same time; One side-20s: photoactivation for 20 s at one proximal face of the bracket only; and One side-10s: photoactivation for 10 s only at one proximal face of the bracket. SBS was tested immediately or after 1000 thermal cycles. Adhesive remnant index (ARI) was classified. Data were subjected to two-way ANOVA and Student-Newman-Keuls' test (α=0.05). Pooled means ± standard deviations for SBS to enamel (MPa) were: 10.2±4.2 (Control), 9.7±4.5 (Simultaneous), 5.6±3.1 (One side-20s), and 4.6±1.9 (One side-10s). Pooled SBS data for immediate and thermal cycled groups were 6.3±2.6 and 8.8±5.2. A predominance of ARI scores 1-2 and 0-1 was observed for the immediate and thermally cycled groups, respectively. In conclusion, simultaneous photoactivation of the orthodontic cement using two light-curing units, one positioned at each proximal face of the bracket, yielded similar bonding ability compared to the conventional light-curing method. Photoactivation of the orthodontic cement at one proximal face of the bracket only is not recommended, irrespective of the light-curing time used.</p>

scholarly journals Effect of etching and light-curing time on the shear bond strength of a resin-modified glass ionomer cement

2010 ◽  
Vol 21 (6) ◽  
pp. 533-537 ◽  
Author(s):  
Ivan Toshio Maruo ◽  
Juliana Godoy-Bezerra ◽  
Armando Yukio Saga ◽  
Orlando Motohiro Tanaka ◽  
Hiroshi Maruo ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Polyacrylic Acid ◽  
Shear Bond Strength ◽  
Glass Ionomer Cement ◽  
Curing Time ◽  
Glass Ionomer ◽  
Resin Modified Glass Ionomer ◽  
Light Curing ◽  
Ionomer Cement

The aim of this study was to assess the influence of etching and light-curing time on the shear bond strength (SBS) and adhesive remnant index (ARI) of a resin-modified glass ionomer cement (RMGIC) upon debonding of orthodontic brackets. Sixty-eight bovine permanent incisors were obtained and embedded in acrylic resin. Edgewise metallic brackets were bonded to the teeth with Fuji Ortho LC RMGIC. The specimens were randomly assigned to 4 groups, using the following etching and light-curing times: G1: 10% polyacrylic acid and 40 s (control); G2: 37% phosphoric acid and 40 s; G3: 10% polyacrylic acid and 50 s; and G4: 37% phosphoric acid and 50 s. Shear test was performed at 0.5 mm/min and the ARI was assessed. G2 (3.6 ± 0.98 MPa) presented significantly higher (p<0.05) SBS than G1 (2.76 ± 0.86 MPa) and G4 (2.86 ± 0.68 MPa), and there was no statistically significant difference (p>0.05) between G2 and G3 (2.94 ± 0.67 MPa). ARI presented prevalence of scores 2 and 3 in all groups. RMGIC SBS enhanced with 37% phosphoric acid etching and 40 s light-curing time, but this did not occur when the light-curing time was increased, regardless of the acid used. RMGIC presented prevalence of failures at the adhesive/bracket interface.

scholarly journals Evaluation of Two Resin Composites Having Different Matrix Compositions

2020 ◽  
Vol 8 (3) ◽  
pp. 76
Author(s):  
Tarek M. Elshazly ◽  
Christoph Bourauel ◽  
Dalia I. Sherief ◽  
Dalia I. El-Korashy
Keyword(s):  
Vickers Microhardness ◽  
Resin Composite ◽  
Blue Dye ◽  
Resin Composites ◽  
Methylene Blue Dye ◽  
Curing Time ◽  
Micro Computed Tomography ◽  
Time Data ◽  
Polymerization Shrinkage ◽  
Dye Penetration

This study compared two resin composites with similar filler systems and different matrix compositions. The depth of cure (DoC), polymerization shrinkage, and marginal leakage were evaluated. A Filtek Bulk Fill resin composite (FB) and a Filtek Supreme resin composite (FS) were used. For the DoC and polymerization shrinkage, cylindrical specimens with different thicknesses were prepared. The DoC was attributed to the bottom/top ratios of Vickers microhardness numbers. For polymerization shrinkage, each specimen was firstly scanned using micro-computed tomography (µCT) then cured for 20 s, then for 10 s, and then for 10 s, and they were rescanned between each curing time. Data were processed using the Mimics software. For marginal leakage, standardized 5 mm cavities were prepared in 90 molars. After etching and bonding, materials were packed according to groups: FB-bulk, FB-incremental, and FS-incremental, which were cured for 20, 30, and 40 s, respectively. After thermo-cycling, teeth were stored in 1% methylene blue dye for 24 h and then sectioned and observed for dye penetration. The results showed insignificant differences in the shrinkage and leakage between the different packing techniques and curing times of both materials. In conclusion, the introduction of a novel matrix into resin composite composition enabled bulk-filling in one layer up to 5 mm deep while keeping a tolerable polymerization shrinkage.

scholarly journals Assessment of the mechanical properties of glass ionomer cements for orthodontic cementation

2012 ◽  
Vol 17 (6) ◽  
pp. 154-159 ◽  
Author(s):  
Marcel M. Farret ◽  
Eduardo Martinelli de Lima ◽  
Eduardo Gonçalves Mota ◽  
Hugo Mitsuo S. Oshima ◽  
Gabriela Maguilnik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Resin Modified Glass Ionomer ◽  
Strength Tests ◽  
Diametral Tensile Strength

OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.

scholarly journals Effect of Surface Treatment and Storage Time on Immediate Repair Bond Strength Durability of Methacrylate- and Ormocer-Based Bulk Fill Resin Composites

2020 ◽  
Vol 10 (22) ◽  
pp. 8308
Author(s):  
Farid S. El-Askary ◽  
Sara A. Botros ◽  
Mutlu Özcan
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Shear Bond Strength ◽  
Storage Time ◽  
Strength Testing ◽  
Repair System ◽  
Resin Composites ◽  
Oxygen Inhibition ◽  
And Storage ◽  
Effect Of Surface

The aim of this study was to evaluate the effect of surface treatment and storage time on immediate repair bond durability of methacrylate- and ormocer-based bulk fill composites. In total, 265 discs were divided into 32 groups (n = 8/group) according to: (1) Material: X-tra fil and Admira Fusion X-tra; (2) Surface treatment: oxygen inhibition; matrix; Futurabond M+; Silane/Futurabond M+; Admira Bond; Silane/Admira Bond; ceramic repair system; and Silane/Cimara bond; and (3) Storage time: 24 h and 6 months. Each disc received three micro-cylinders from the same material. Specimens were subjected to micro-shear bond strength testing either at 24 h or 6 months. Data were analyzed using ANOVA/Tukey’s test/Student t-test (p = 0.05). All experimental factors had significant effect on bond strength (p < 0.0001). Drop in bond strength was noticed in both materials after six months (p < 0.05), except for Admira Fusion X-tra treated with silane/cimara adhesive (p = 0.860). Both materials showed insignificant values with Admira bond either at 24 h or 6 months (p = 0.275 and p = 0.060, respectively). For other treatments, X-tra fil showed significantly higher values at 24 h and 6 months (p < 0.05). Ceramic repair system can be used to immediately repair both methacrylate- and ormocer-based composites.

The Silorane-based Resin Composites: A Review

2017 ◽  
Vol 42 (1) ◽  
pp. E24-E34 ◽  
Author(s):  
GA Maghaireh ◽  
NA Taha ◽  
H Alzraikat
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Clinical Significance ◽  
Physical And Mechanical Properties ◽  
Marginal Adaptation ◽  
Resin Composites ◽  
Restorative Material ◽  
Polymerization Shrinkage ◽  
Tooth Structure

SUMMARY This article aims to review the research done on the silorane-based resin composites (SBRC) regarding polymerization shrinkage and contraction stresses and their ability to improve the shortcomings of the methacrylate-based resin composites (MRBC). Special attention is given to their physical and mechanical properties, bond strength, marginal adaptation, and cusp deflection. The clinical significance of this material is critically appraised with a focus on the ability of SBRC to strengthen the tooth structure as a direct restorative material. A search of English peer-reviewed dental literature (2003-2015) from PubMed and MEDLINE databases was conducted with the terms “low shrinkage” and “silorane composites.” The list was screened, and 70 articles that were relevant to the objectives of this work were included.

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