Effect of light-curing distance and curing time on composite microflexural strength

This study investigated the influence of curing distance on µ-flexural strength (µ-FS) a nano-hybrid composite, cured using manufacturer-recommended time (MCT), compared to consistent radiant exposure (CRE) three different light-curing units (LCUs). Beams (6×2×1 mm) were MCT or CRE with quartz-tungsten-halogen (QTH); single-emission-peak light-emitting-diode (SLED), multiple-emission-peak (MLED) LCU. Specimens at 0-, 2- 8-mm distances (n=10) and bottom irradiance measured Managing Accurate Resin Curing-Resin Calibrator spectrometer. µ-FS testing was performed, data analyzed two-way ANOVA Tukey multiple comparison tests (α=0.05). Mean (25.4–99.7 mW/cm2) (0.31–1.11 J/cm2). 422.1–516.6 MPa (MCT) 440.4–490.4 (CRE). Comparing showed that significantly decreased 2-mm (QTH) (SLED). may be impacted by protocol.