Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins

Abstract

Statement of problem. The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown.

Purpose. The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials.

Material and methods. Forty disks (10x2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (R-a) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (Delta E-00) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (alpha=.05).

Results. The surface treatment technique significantly affected the Ra values of the composite resins tested (P<.001). The interaction between the surface treatment technique and composite resin material was also significant for Delta E-00 values (P<.05). Within the composite resin groups, significant decreases in Ra were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (P<.05). Scanning electron microscope images revealed rougher surfaces with conventionally polished groups compared with test groups. Conventionally polished groups had the highest Delta E-00 (3.09 to 3.49) values for each composite resin group, except for BisCover applied Clearfill Majesty (P<.05). Within the composite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (P<.05).

Conclusions. Using Palaseal agent on all tested composite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin.