Effect of Different LED Light-curing Units on Degree of Conversion and Microhardness of Bulk-fill Composite Resin

Effect of Polywave and Monowave Light Curing Units on the Microtensile Bond Strength and Failure Types of Different Bulk-Fill Resin Composites: An in vitro Study

“…The results obtained in the present study are in agreement with those obtained by Tsuzuki et al, 1 Varshney et al, 33 Siagian et al, 34 and Alavi et al, 35 who reported that LED polywaves allow for a higher degree of conversion in composites containing camphorquinone (CQ) associated with alternative photoinitiators requiring shorter wavelengths. This was the case for the Opus Bulk Fill and Tetric N-Ceram Bulk Fill which presented higher bond strength values, probably because of the presence of alternative photoinitiators intended to enhance light-curing.…”

“…In addition, the refractive index of the resin composite monomers matches that of the filler particles, leading to a translucent structure that facilitates light penetration with an adequate depth of cure. 5 , 20 , 34 Therefore, the presence of ivocerin causes a short light application time with high power (1400 mW/cm 2 × 12s), producing sufficient radicals. Additionally, the Tetric N-Ceram Bulk Fill, which counteracts the shrinkage phenomenon, contains urethane dimethacrylate (UDMA) which is responsible for specific chain transfer reactions and provides an alternative pathway for further polymerization.…”

“… 1 , 6 , 23 This reaction generates faster movement of radicals in the chain structure, resulting in enhanced polymerization and monomer conversion by achieving high reactivity and conversion rates with lower shrinkage. 1 , 34 , 45 In addition, Tetric N-Ceram Bulk Fill contains prepolymerized particles that also play a role in reducing polymerization stress, which would improve some of its mechanical properties. 21 Despite the above, the Tetric N-Ceram Bulk Fill exhibited lower bond strength at standard power (1000 mW/cm 2 × 20s), which contradicts the results of Besegato et al, 5 who reported that low-power irradiation over a long time interval provides slower polymerization, thus improving the mechanical properties of resin composites by forming longer chains with higher molecular weights than those formed with high-power irradiation.…”

Decálogo de buenas prácticas para el uso y mantenimiento de las Unidades de Fotocurado LEDs

“…Imagen de autoría propia do generar una exposición por debajo de la densidad de energía óptima, dando como resultado una polimerización incompleta lo que disminuye la dureza superficial, los valores de adhesión, las propiedades mecánicas, aceleración del desgaste, deterioro marginal y aumento de la citotoxicidad. (20,21) Figura 2…”

An in Vitro Comparative Evaluation for Internal and Marginal Integrity and the Degree of Monomer Conversion of Alkasite Restorative Material

“…Due to unreacted monomer remaining in the polymer's cross-linked structure, composite resins with low monomer conversion rates exhibit undesirable properties like increased bacterial colonization, discoloration, lower bond strength, low wear resistance, margin breakdown, water sorption, decreased hardness, and decreased durability. 13 Because resin composite technology is developing quickly and new products are coming out on the market every year, it is crucial for academics and clinicians to understand the different properties of the materials they use in restoration, so further knowledge of alkasite restoration in comparison with other commonly used restorations is necessary. The objective of the current study was to compare an alkasite restoration's internal and marginal adaption.…”