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>

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 Shear Strength of Brackets Bonded with Universal Adhesive Containing 10-MDP after 20,000 Thermal Cycles

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Mariana Almeida Mello Proença ◽  
Karime Tavares Lima da Silva ◽  
Alisson Costa e Silva ◽  
Edilausson Moreno Carvalho ◽  
José Bauer ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dental Enamel ◽  
Adhesive System ◽  
Test Machine ◽  
Adhesive Systems ◽  
Thermal Cycles ◽  
Universal Adhesive ◽  
Adhesive Remnant Index ◽  
One Way Anova

Objectives. The aim of this study was to evaluate the shear bond strength of metal brackets bonded with different universal adhesive systems containing 10-MDP and Transbond Plus Self Etching Primer after 20,000 thermal cycles. Materials and Methods. A total of 130 sound bovine teeth were used, which are divided into 5 groups (n = 26) according to the adhesive system used: All-Bond Universal (Bisco), Ambar Universal (FGM), Clearfil Universal Bond (Kuraray), Single Bond Universal (3M/ESPE), and Transbond Plus SEP (3M/ESPE) as control. The adhesives were applied for 20 seconds and bonded with a resin Transbond XT (3M/ESPE). After this, the teeth were submitted to 20,000 cycles at 5°C and 55°C. Afterwards, the shear bond strength test was performed in a universal test machine (Instron 3342). The adhesive remnant index (ARI) was evaluated under a stereomicroscope at 10x magnification and scanning electronic microscopy (SEM, Hitachi 3030). The shear bond strength data were submitted to One-Way ANOVA (α = 0.05) and the ARI to the Kruskal–Wallis test (α = 0.05). Results. Statistical analysis showed that the universal adhesive systems presented mean shear bond strength values similar to Transbond Plus SEP (p<0.05). The universal adhesive presented similar ARI values among them but differed from those of Transbond Plus SEP (p<0.001). Transbond Plus SEP presented a high ARI value when compared with the universal adhesive systems and high demineralization of enamel. Conclusions. The results show that universal adhesive systems may be used for bonding metal brackets if the orthodontist wants to maintain dental enamel health.

scholarly journals Light Activation and Thermocycling Methods on the Shear Bond Strength of Brackets Bonded to Porcelain Surfaces

2020 ◽  
Vol 31 (1) ◽  
pp. 52-56
Author(s):  
Gustavo Vallandro Lopes ◽  
Lourenço Correr-Sobrinho ◽  
Américo Bortolazzo Correr ◽  
Ana Paula Terossi de Godoi ◽  
Silvia Amélia Scudeler Vedovello ◽  
...  
Keyword(s):  
Bond Strength ◽  
Analysis Of Variance ◽  
Hydrofluoric Acid ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Deionized Water ◽  
Light Activation ◽  
Thermal Cycles ◽  
Adhesive Remnant Index ◽  
Significant Difference

Abstract The present study was evaluated the effect of different light activation and thermocycling methods on the shear bond strength (SBS) and on the adhesive remnant index (ARI) of metal brackets bonded to feldspathic ceramic. Hundred metal brackets were bonded to 20 porcelain cylinders, divided into four groups (n=25) based on light activation and thermocycling processes. The cylinders were etched with 10% hydrofluoric acid for 60 s and coated with two layers of silane. The brackets were bonded with Transbond XT composite resin. Light activation in Groups 1 and 3 was performed during 3 s using the VALO Ortho Cordless appliance with irradiance 3,200 mW/cm2 and in Groups 2 and 4 for 40 s using Optilight Max appliance with irradiance 1,200 mW/cm². The samples were stored in deionized water at 37°C for 24 h and the samples from Groups 1 and 2 were submitted to the SBS test at a rate of 1 mm/min, whereas the samples from Groups 3 and 4 were submitted to 7,000 thermal cycles (5°/55°C) before to the SBS test. The data were assessed by two-way analysis of variance and by Tukey’s test (a=0.05). No significant difference was observed between SBS means in the different light activation devices used. The samples subjected to thermocycling revealed lower SBS values (p≤0.05). There was predominance of score 0 for ARI in all groups. Therefore, the different light activation methods did not interfere in SBS, but thermocycling reduced SBS.

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 In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

2013 ◽  
Vol 18 (3) ◽  
pp. 124-129 ◽  
Author(s):  
Murilo Gaby Neves ◽  
Gustavo Antônio Martins Brandão ◽  
Haroldo Amorim de Almeida ◽  
Ana Maria Martins Brandão ◽  
Dário Ribeiro de Azevedo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Statistical Difference ◽  
Testing Machine ◽  
Adhesive Remnant Index ◽  
Light Curing ◽  
Scanning Electron

OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL) and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL) used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI) and enamel condition in scanning electron microscopy (SEM). METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM) analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

scholarly journals Comparison of shear bond strength of orthodontic bracket bonding to teeth using light-curing units between halogen and LED: An in vitro study

2019 ◽  
Vol 45 (1) ◽  
pp. 17-22
Author(s):  
Md Kamal Abdullah ◽  
Tanzila Rafique ◽  
Ashis Kumar Biswas ◽  
Ranjit Ghosh ◽  
Md Abdul Gafur ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
In Vitro Study ◽  
Vitro Study ◽  
Tooth Surface ◽  
Advantages And Disadvantages ◽  
Adhesive Remnant Index ◽  
Halogen Light ◽  
Light Curing

Background: Light-cured bonding systems have been widely accepted among orthodontists. Various light curing units are available now. Recently, the light emitting diode (LED) has been introduced alongside halogen light curing units. There is lack of information on the advantages and disadvantages of different light curing systems. The aim of this in vitro study was to compare the shear bond strength of orthodontic brackets and adhesive remnant index (ARI) of an adhesive cured with two different orthodontic light sources i.e. LED and halogen. Methods: Forty four (22 in each group) extracted human premolars without any defects were etched with 37% phosphoric acid and cleansed with water spray and air dried. The sealant (Ortho Solo) was applied on the tooth surface and the brackets were bonded using adhesive (Enlight). Adhesives were cured with Halogen (Litex) and LED (D-LUX) for 40 seconds. Then the specimens were debonded later using a universal testing machine, with crosshead speed of 0.2 mm/min until the brackets were detached. Adhesive remnant index (ARI) scores were assessed under stereomicroscope at ×10 magnification. Results: The shear bond strength in Halogen group was 19.73 ± 3.44 MPa and in the LED group 20.81±3.02 MPa which is little higher than halogen group. The proportion of being adhesive remaining index for ARI Score 1 in Halogen group was 5 (22.7%) and in LED group 7 (31.8%). While ARI Score 2 in the Halogen group was 13 (59.1%) compared to LED group 8 (36.4%). However, ARI Score 3 in Halogen group was 4 (18.2%) and in LED group 7 (31.8%). The overall model showing no significant difference. Conclusion: Within limitations, this in vitro study showed the shear bond strength of orthodontic adhesives cured with a LED was statistically equivalent to those cured with a halogen light curing unit. There were significant differences in the ARI scores of the light-curing units tested. LED light-curing units can be suggested for the polymerization of orthodontic bonding adhesives because it showed a balanced effect on ARI index. Bangladesh Med Res Counc Bull 2019; 45: 17-22

scholarly journals Shear bond strength evaluation of bonded molar tubes on fluorotic molars

2012 ◽  
Vol 83 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Erika L. Silva-Benítez ◽  
Veronica Zavala-Alonso ◽  
Gabriel A. Martinez-Castanon ◽  
Juan P. Loyola-Rodriguez ◽  
Nuria Patiño-Marin ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dental Fluorosis ◽  
In Vitro Study ◽  
Mean Value ◽  
Fixed Appliance ◽  
Adhesive Remnant Index ◽  
The Mean ◽  
Electronic Microscope

Abstract Objective: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. Materials and Methods: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. Results: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. Conclusions: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.

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