Title: 0633 - Effect of Time and Temperature on Color Stability of Resin-Composite
Arwa Alhakami (Presenter)
University Of Iowa
Rodrigo Maia, University of Iowa
Fang Qian, University of Iowa College of Dentistry
Cristina Vidal, university of iowa college of dentistry
Teresa Marshall, University of Iowa
Objectives: To evaluate the effect of different exposure time and coffee temperatures on the color stability of three types of resin-composites
Three types of resin-composites were used to prepare 54 discs (n=18/per-composite): microfill, microhybrid, and nanofilled (shade A2). Discs were 2mm in thickness and diameter. After light curing (using an LED curing light), the discs were finished and polished using sand paper under water irrigation. Samples were stored in an incubator in distilled water for 24-hours at 37 celsius-degree. Each composite-resin group was randomly further divided to 6 subgroups (n=3): hot coffee 65 celsius-degree, 37 celsius-degree coffee, cold coffee 4 celsius-degree, hot distilled water 65 celsius-degree, 37 celsius-degree distilled water, cold distilled water 4 celsius-degree (control group). All samples were placed in an incubator at the group-specific temperature.
Baseline color measurements were conducted using a spectrophotometer. The color changes (Delta E*) were recorded after 24-hours, 3.5-days, and 7-days.
Descriptive statistics and a two-way repeated measures ANOVA, with the post-hoc contrast test were conducted to detect the difference in color stability (Delta E*) between the three temperatures for each composite over the three time periods (alpha=0.05).
Results: Exposure time and interaction between temperature and time were non-significant for the three resin-composite groups. However, the data revealed a significant effect for the temperature on Delta E* for the three resin-composites (p<0.05 in each instance). Moreover, for each of the three resin-composites, the mean Delta E* obtained at 65 celsius-degree temperature was significantly greater than that observed at 4 celsius-degree and 37 celsius-degree while no significant difference was found between 4 celsius-degree and 37 celsius-degree.
Within the limitations of this study, the results indicated that higher temperature affects the color stability of resin-composite more than lower temperatures.
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE