Compressive Strength of Composite Resins at Different Exposure Time Using LED and Halogen Units

Abstract

OBJECTIVE: To evaluate the compressive strength of resin composites cured with a QTH lamp & LED unit at different exposure time. STUDY DESIGN: In Vitro Experimental study METHODOLOGY: Two composite materials were used in this study. Filtek Z250, (3M ESPE Dental products) and Filtek P60 (3M ESPE Dental products). For each composite 114 disc shaped samples were prepared (5mm in diameter and 2mm in thickness) by using stainless steel mold. The mold was packed with the bulk of resin composite by incremental technique. Each sample was cured through the polyester strip with either QTH unit or LED unit depending on samples grouping. Samples were irradiated for 20, 30 and 40 seconds. Nineteen specimens were prepared for each experimental group. Specimens were placed in artificial saliva for 24 hours after curing. Compressive strength was then determined in universal Instron Testing Machine. Data was analyzed by factorial design by Three Way ANOVA and post hoc Tukeys HSD test. Units RESULTS: Halogen light curing unit is more effective then LED unit in terms of compressive strength. Compressive strength was influenced by exposure time (20, 30 or 40 s) (p<0.001), by curing lights (QTH or LED) (p<0.001) and by resin composite (Filtek Z250 or ZP60) (p<0.001). CONCLUSIONS: The compressive strength of specimens cured with a QTH and a LED curing light was influenced by the curing unit and the chemical composition of the material. The study concluded that superiority of LEDs over halogen lamps is questionable with different composite resins.

Antibacterial Activity of Dental Composite with Ciprofloxacin Loaded Silver Nanoparticles

“…For confirmation, these colonies were streaked on blood agar plates and were isolated after incubation. For the microcosm model, an inoculum was prepared by the saliva sample dilution with sterile glycerol of 30% in concentration [ 28 ].…”

Effectiveness of Se/ZnO NPs in Enhancing the Antibacterial Activity of Resin-Based Dental Composites

“…A universal testing machine (Instron universal testing machine model static) at a crosshead speed of 0.5 cm/min and load cell of load cell 5 KN were used to measure the compressive strength. Specimens were placed horizontally on the machine’s base, and the compressive load was applied until fracture [ 31 ]. The unit of measured strength was MPa, and the Compressive strength (CS) was calculated by using this formula: …”

Comparación in vitro de la resistencia a la compresión y resistencia flexural de resinas Bulk Fill (Opus™ Bulk Fill, Tetric® N-Ceram Bulk Fill y Filtek™ Bulk Fill)

“…(9) La importancia de este estudio radica en que ante la existencia de nuevos materiales de resina tipo Bulk Fill, es necesario evaluar la resistencia a la compresión y resistencia flexural de estos ya que ambas se reproducen en el proceso masticatorio y se consideran indicadores de la durabilidad para estos. (17,18) En la presente investigación se hizo uso de la máquina de ensayo universal Instron ® con la finalidad de evaluar dos propiedades mecánicas (resistencia a la compresión y resistencia flexural). Este tipo de máquina también ha sido utilizada por diversos autores, con aditamentos en forma de platos de compresión (Resistencia a la compresión) por Galvão R. y col.(2013) (19) , Narasimha J. y col. (2013) (14) , Atabek D y col. (2014) (15) , Vandana y col.…”

“…(2018) utilizaron muestras de 5x2mm (18) , etc. A diferencia de los autores antes mencionados, para este estudio se emplearon muestras de 3mm de diámetro x 5mm de alto.…”