Influence of light energy density on heat generation during photoactivation of dental composites with different dentin and composite thickness

Guiraldo, Ricardo Danil; Consani, Símonídes; Souza, Aline Simprine de; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço

doi:10.1590/s1678-77572009000400005

Cited by 12 publications

(12 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that the DC can be accelerated by dynamic heating of composite materials 4,5,7-10,22. This study, as well, showed that preheating the composites may increase the extent of polymerization for both of the composites examined.…”

Section: Discussionsupporting

confidence: 60%

Polymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

et al. 2011

View full text Add to dashboard Cite

PURPOSEHeat of composite polymerization (HP) indicates setting efficacy and temperature increase of composite in clinical procedures. The purpose of this in vitro experimental study was to evaluate the effects of 5 temperatures on HP of two new composites.MATERIALS AND METHODSFrom each material (Core Max II [CM] and King Dental [KD]), 5 groups of 5 specimens each were prepared and their total HPs (J/gr) were measured and recorded, at one of the constant temperatures 0℃, 15℃, 23℃, 37℃ and 60℃ (2 × 5 × 5 specimens) using a differential scanning calorimetry (DSC) analyzer. The data were analyzed using a two-way ANOVA, a Tukey's test, an independent-samples t-test, and a linear regression analysis (α=0.05).RESULTSNo polymerization reactions occurred at 0℃; then this temperature was excluded from statistical analyses. The mean HP of the remaining 20 KD specimens was 20.5 ± 14.9 J/gr, while it was 40.7 ± 12.9 J/gr for CM. The independent-samples t-test showed that there were significant differences between the HP of the two materials at the temperatures 15℃ (P=.0001), 23℃ (P=.0163), 37℃ (P=.0039), and 60℃ (P=.0106). Linear regression analysis showed statistically significant correlations between environment temperatures and HP of CM (R2=0.777).CONCLUSIONUsing CM is advantageous over conventional composite because of its better polymerization capacity. However due to its high HP, further studies should assess its temperature increase in vivo. Preheating KD is recommended. Refrigerating composites can negatively affect their polymerization potential.

show abstract

Section: Discussionsupporting

confidence: 60%

Polymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

et al. 2011

View full text Add to dashboard Cite

show abstract

“…In addition to the heat produced by the LED-LCU, the polymerization of the composite (i.e., exothermic reaction) has been discussed as causes for tissue damage (i.e., pulp damage) [ 8 , 11 , 15 , 16 ]. The light source is still, however, considered to be the main risk [ 17 ], even though the composite and the remaining dental hard tissue may give some protection [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Light-curing units used in dentistry: factors associated with heat development—potential risk for patients

et al. 2016

View full text Add to dashboard Cite

ObjectivesTo investigate how heat development in the pulp chamber and coronal surface of natural teeth with and without cusps subjected to irradiance using light-emitting diode (LED)–light-curing units (LCUs) is associated with (i) irradiance, (ii) time, (iii) distance, and (iv) radiant exposure.Materials and methodsThree different LED-LCUs were used. Their irradiance was measured with a calibrated spectrometer (BlueLight Analytics Inc., Halifax, Canada). An experimental rig was constructed to control the thermal environment of the teeth. The LED-LCU tip position was accurately controlled by a gantry system. Tooth surface temperature was measured by thermography (ThermaCAM S65 HS, FLIR Systems, Wilsonville, USA) and pulp chamber temperature with a thermocouple. LED-LCU tip distance and irradiation times tested were 0, 2, and 4 mm and 10, 20, and 30 s, respectively. Ethical permission was not required for the use of extracted teeth.ResultsMaximum surface and pulp chamber temperatures were recorded in tooth without cusps (58.1 °C ± 0.9 °C and 43.1 °C ± 0.9 °C, respectively). Radiant exposure explained the largest amount of variance in temperature, being more affected by time than irradiance.ConclusionsAt all combinations of variables tested, repeated measurements produced consistent results indicating the reliability of the method used. Increased exposure time seems to be the factor most likely to cause tissue damage.Clinical relevanceRisk of superficial tissue damage at irradiances >1200 mW/cm2 is evident. There is a risk of pulp damage when only thin dentin is left at higher irradiances (>1200 mW/cm2). Clinicians should be aware of LED-LCU settings and possible high temperature generated.

show abstract

“…Various factors, including type of LCU (8), chemical composition of the restorative material (9,10), heat conduction properties of composite resins (10,11), restoration thickness (10,11), and dentin thickness (12), may influence the intensity of temperature rise during photoactivation (10). Thus, temperature changes have been studied in dental composite resins in experimental conditions using an elastomer mold, a base of chemically polymerized acrylic resin, bovine dentin slice and thermocouple (8,12) or bovine incisor crowns and thermocouple (13). In an in vivo experiment, Zach and Cohen (14) verified that teeth from Rhesus monkeys submitted to different temperature increases suffered irreversible pulp changes due to the elevation of temperature inside the pulp chamber.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Silorane and Methacrylate-Based Composites on the Polymerization Heat Generated with Different Light-Curing Units and Dentin Thicknesses

Guiraldo¹,

Consani

Berger³

et al. 2013

Braz. Dent. J.

Self Cite

View full text Add to dashboard Cite

This study evaluated the temperature variation in the pulp chamber during photoactivation of two restorative composite resins (Filtek P90 silorane-based composite and Heliomolar methacrylate-based composite) with either a quartz-tungsten-halogen (QTH) or light-emitting diodes (LED) light-curing unit (LCU) and using dentin thicknesses (0.5 and 1.0 mm). Standardized cavities (2x2x2 mm) were prepared in 80 bovine incisors, which were randomly assigned to 8 groups according to the photoactivation method and dentin thickness. Filtek P90 and Heliomolar (both in shade A3) were used with their respective adhesive systems (P90 self-etch primer / P90 adhesive bond and Excite adhesive). All experiments were carried out in a controlled environment (37°C). The temperature variations (°C) were recorded using a digital thermometer attached to a K-type thermocouple. The results were analyzed statistically by ANOVA and Tukey's test (α=0.05). For composite/dentin thickness interaction, temperature increase was significantly higher in 0.5 mm dentin thickness (40.07°C) compared with 1.0 mm dentin thickness (39.61°C) for Filtek P90. For composite/LCU interaction, the temperature increase was significantly higher for Filtek P90 (39.21°C - QTH and 40.47°C - LED) compared with Heliomolar (38.40°C - QTH and 39.30°C - LED). The silorane-based composite promoted higher temperature increase in the pulp chamber than the methacrylate-based composite.

show abstract

Influence of light energy density on heat generation during photoactivation of dental composites with different dentin and composite thickness

Cited by 12 publications

References 14 publications

Polymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

Polymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

Light-curing units used in dentistry: factors associated with heat development—potential risk for patients

Comparison of Silorane and Methacrylate-Based Composites on the Polymerization Heat Generated with Different Light-Curing Units and Dentin Thicknesses

Contact Info

Product

Resources

About