Color stability of repairs on bis‐acryl resin submitted to thermal aging and immersion in beverages

Abstract

Objective Defects/bubbles can occur during the manufacture of bis‐acryl resin provisional restorations, requiring repair or new prosthesis. This study evaluated the color stability of bis‐acryl resin specimens repaired, aging, and immersioned in beverages. Material and methods Eighty disks were made of bis‐acryl resin. Twenty disks were not repaired (BCR), 20 disks were repaired with the same bis‐acryl resin (BCR‐BCR), 20 disks were repaired with flowable resin (BCR‐FR), and 20 disks received an adhesive layer prior to flowable resin repair (BCR‐AFR). Coordinates L*a*b* were obtained. Ten disks from each group were thermocycled (5000 cycles) and the others were immersed in coffee with sugar (n = 5) and cola‐based soft drinks (n = 5) for 7 days. Color, lightness, chroma, and hue differences were calculated by the CIEDE2000 formula, analyzed by two‐way analysis of variance. Multiple comparisons were made with the Tukey's HSD test (α = .05). Results BCR‐FR group presented the highest color differences (5.6) between groups repaired (P < .001). BCR‐BCR group showed the smallest color differences (0.9) after aging (P = .003), but the greatest variation between T0 and T1 (about 1 ΔE). BCR‐ARF immersed in coffee showed the greatest color differences (20.6) (P < .001). Conclusions Aging and immersion altered the colorimetric behavior of repairs, especially after the use of coffee. Clinical implications Repairs are indicated when defects and bubbles are present in the surface of the bis‐acryl resin provisional restorations after its manufacture. However, they may present noticeable color changes, especially when the use of coffee is frequent.

Color and surface gloss stability of bis-acryl and resin composite after exposure to cigarette smoke

“…Regarding bis-acryl resins, studies that evaluated their behavior in staining solutions concluded that pigments may be able to penetrate the material through the gaps formed after the setting reaction, since bis-acryl resins have a more heterogeneous composition, which facilitates staining and consequent absorption of pigments [19][20][21]. However, there are few studies that assess the color stability of this group of resins, including aging by cigarette smoke.…”

Degree of conversion and water sorption of self-adhesive and conventional flowable composites

“…In addition, a correlation has been reported between the residual double bonds and internal color change of light-cure composite resins 10 . The possible causes include oxidation of unreacted double bonds, and chemical degradation and formation of colored degradation products 10,12 .…”