The effects of light curing units and environmental temperatures on C = C conversion of commercial and experimental bonding agents.
Polymerization of bonding agents (BA) is a critical factor in determining the success of bonded restorations. We aimed to assess the effects of two light curing units and two temperatures on the extent of polymerization (EP) of a commercial BA and an experimental BA.



Forty BA specimens were randomly divided into 8 subgroups of n = 5 to compare the polymerization of two BAs (experimental/Scotchbond) based on the variables: temperature (23/37 °C) and light-curing unit (quartz-tungsten-halogen/light-emitting diode). The EP (%) was measured using differential scanning calorimetry, and analyzed using the t-test, two- and three-way analyses of variance (ANOVA), and the Bonferroni test (α = 0.05).



There were significant differences between the EP results between the two BAs (P = 0.012) and due to the different temperatures (P = 0.001), but not between the different light-curing units (P = 0.548). The interaction between BA and temperature was significant (P < 0.001). The other interactions were nonsignificant.



The two light-curing units had similar effects on the EP. The EP values were better when curing was performed at human body temperature.
Iranian Tissue Bank & Research Center, Tehran University of Medical Sciences, Tehran, Iran ; Department of Dental Materials, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran ; Research Center for Medical and Technology in Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran.
Tahereh Sadat
TS
Jafarzadeh-Kashi
Department of Pharmaceutics, Pharmacy School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mohmmad
M
Erfan
Orthodontist in Private Practice, Tehran, Iran.
Salmeh
S
Kalbasi
Pharmacist in Private Practice, Tehran, Iran.
Malihe
M
Ghadiri
Iranian Tissue Bank & Research Center, Tehran University of Medical Sciences, Tehran, Iran ; Department of Dental Anatomy and Morphology, Dental Branch, Islamic Azad University, Tehran, Iran.
Vahid
V
Rakhshan
Bonding agent; Dental materials; Differential scanning calorimetry; Extent of polymerization; Light-curing of dental adhesives; Light-curing units; Polymerization; Temperature