Bulk Fill Kompozitlerde Ön Isıtmanın Renk Değişimine ve Mikrosertliğe Etkisi

Abstract

Challenges associated with the use of resin-based composites have made the development of bulk-fill composites inevitable, allowing increased polymerization depth and the placement of thick layers in a single increment. Preheating has provided several advantages in improving the mechanical properties of bulk-fill composites and facilitating their placement into the cavity. In this study, it was aimed to evaluate the effects of preheating on the color stability and microhardness changes of bulk-fill composites. For this purpose, a total of n=90 samples were prepared from three different composite materials, and n=15 samples from each composite group were subjected to preheating prior to polymerization. Color and microhardness values of each sample were measured before the aging process. Color measurements were performed using a Konica Minolta CM-17d spectrophotometer, and microhardness measurements were conducted using a Shimadzu HMV-2 microhardness tester. The samples were then subjected to 300 hours of accelerated aging in a QUV aging device, after which color and microhardness measurements were repeated. Color differences were calculated according to the CIELab formula. The differences between the initial and final microhardness values were also calculated. The obtained data were analyzed using two-way ANOVA. Preheating was found to have no significant effect on color change or microhardness change (p>0.05). The GrandioSO x-tra bulk-fill composite demonstrated superior color stability compared to the other brands. All samples exhibited color changes above the perceptibility and clinical acceptability thresholds.