Changes in irradiance and energy density in relation to different curing distances

Beolchi, Rafael Silva; Moura-Netto, Cacio; Palo, Renato Miotto; Torres, Carlos Rocha Gomes; Pelissier, Bruno

doi:10.1590/1807-3107bor-2015.vol29.0060

Cited by 37 publications

(31 citation statements)

References 23 publications

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“…During the past decade, resin-based composite has become the most commonly used restorative material worldwide due to its aesthetic and adhesive properties. Clinically, these materials require careful attention to the presence and/or risk of salivary contamination, proper removal of solvents [26,27] and power energy for proper polymerization [28]. While composites have relatively good adhesive or sealing properties, polymerization shrinkage of the resin during curing combined with cyclic occlusal loading may impose internal stresses [29].…”

Section: Discussionmentioning

confidence: 99%

A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties

Geraldeli

Soares

Alvarez

et al. 2017

Journal of Dentistry

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Secondary caries at the margins of composite restorations has been attributed to adhesive failure and consequent accumulation of cariogenic biofilms. Objectives To develop and evaluate an etch-and-rinse adhesive system containing arginine for sustainable release and recharge without affecting its mechanical properties. Arginine metabolism by oral bacteria generates ammonia, which neutralizes glycolytic acids and creates a neutral environmental pH that is less favorable to the growth of caries pathogens, thus reducing the caries risk at the tooth-composite interface. Methods Experimental adhesives were formulated with methacrylate monomers and arginine at 5%, 7%, and 10% or no arginine (control). Adhesives were tested for: (i) mechanical properties of true stress (FS and UTS), modulus of elasticity (E), degree of conversion (DC), Knoop hardness number (KHN) and dentin microtensile bond strength (μ-TBS), (ii) arginine release and recharge, and (iii) antibacterial activities. Data was analyzed by t-test, one-way ANOVA and Tukey's tests. Results FS and UTS results showed no statistically significant differences between the 7% arginine-adhesive and control, while the results for E, DC, KHN and μ-TBS showed no difference among all groups. The 7% arginine-adhesive showed a high release rate of arginine (75.0 μmol/cm2) at 2 h, and a more sustainable, controlled release rate (up to 0.2 μmol/cm2) at 30 days. Conclusions Incorporation of 7% arginine did not affect the physical and mechanical properties of the adhesive. Arginine was released from the adhesive at a rate and concentration that exhibited antibacterial effects, regardless of shifts in biofilm conditions such as sugar availability and pH. Clinical significance Secondary caries is recognized as the main reason for failure of dental restorations. The development of an arginine-based adhesive system has the potential to dramatically reduce the incidence and severity of secondary caries in adhesive restorations in a very economical fashion.

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Section: Discussionmentioning

confidence: 99%

A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties

Geraldeli

Soares

Alvarez

et al. 2017

Journal of Dentistry

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“…Given that dentists wish to reduce the time spent light curing, this value was considered to be the minimum irradiance necessary to adequately polymerize a 2 mm increment of composite (20,21). Six LCUs delivered inadequate irradiance in posterior region: KON-LUX, Altlux II, Biolux Standard, TL-01, Optilux 501, DX Turbo LED 1200.…”

Section: Characteristics Of Light Curing Units Used Inmentioning

confidence: 99%

An Evaluation of the Light Output from 22 Contemporary Light Curing Units

et al. 2017

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This study measured the radiant power (mW), irradiance (mW/cm 2 ) and emission spectra (mW/cm 2 /nm) of 22 new, or almost new, light curing units (LCUs): -Alt Lux II, BioLux Standard, Bluephase G2, Curing Light XL 3000, Demetron LC, DX Turbo LED 1200, EC450, EC500, Emitter C, Emitter D, KON-LUX, LED 3M ESPE, Led Lux II, Optilight Color, Optilight Max, Optilux 501, Poly Wireless, Radii cal, Radii plus, TL-01, VALO Cordless. These LCUs were either monowave or multiple peak light emitting diode (LED) units or quartz-tungstenhalogen LCUs used in anterior and posterior teeth. The radiant power emitted by the LCUs was measured by a laboratory grade laser power meter. The tip area (cm²) of the LCUs was measured and used to calculate the irradiance from the measured radiant power source. The MARC-Patient Simulator (MARC-PS) with a laboratory grade spectrometer (USB4000, Ocean Optics) was used to measure the irradiance and emission spectrum from each LCU three times at the sensor located on the facial of the maxillary central incisors and then separately at the occlusal of a maxillary second molar. The minimum acceptable irradiance level was set as 500 mW/cm 2 . Irradiance data was analyzed using two-way ANOVA and the radiant power data was analyzed by one-way ANOVA followed by Tukey test (α=0.05). In general, the irradiance was reduced at the molar tooth for most LCUs. Only the Valo, Bluephase G2 and Radii Plus delivered an irradiance similar to the anterior and posterior sensors greater than 500 mW/cm 2 . KON-LUX, Altlux II, Biolux Standard, TL-01, Optilux 501, DX Turbo LED 1200 LCUs delivered lower irradiance values than the recommended one used in molar region, KON-LUX and Altlux II LCUs used at the maxillary incisors. Bluephase G2 and Optilight Max delivered the highest radiant power and KON-LUX, Altlux II and Biolux Standard delivered the lowest power. The emission spectrum from the various monowave LED LCUs varied greatly. The multi-peak LCUs delivered similar emission spectra to both sensors.

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“…The concept of total energy demonstrates that the photopolymerization process depends on the energy taken up by the resin, in which irradiance is multiplied by exposure time (15). Previous studies have argued that irradiance should range from 6 to 16 J/cm 2 to be effective, but these values are not absolute as they depend on other factors such as type, thickness, and translucency of the resin and on the type of photoinitiator (11,15). In the present study, exposure to radiation was 9.6 J/cm² for light activation with VALO Ortho Cordless and 48 J/cm² for light activation with Optilight Max.…”

Section: Discussionmentioning

confidence: 99%

“…In line with the findings of the present study, some studies have suggested that the extremely thin layer of resin with no need for deep light activation used for bracket bonding would cancel out the effect associated with the difference in energy uptake, which, by itself, would not be enough to change SBS. In addition, the wavelengths of LED devices would efficiently stimulate camphorquinone, rendering photopolymerization effective, regardless of the difference in energy uptake (4,11).…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2020

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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.

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Changes in irradiance and energy density in relation to different curing distances

Cited by 37 publications

References 23 publications

A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties

A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties

An Evaluation of the Light Output from 22 Contemporary Light Curing Units

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

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