EFFECT OF 2 FLUORESCENT DYES ON COLOR OF RESTORATIVE MATERIALS

Purpose: The objective of these two studies was to determine whether t he use of dyes in vitro would affect the shade of tooth-colored restor ative materials. Materials and Methods: Two separate studies were perf ormed. In Study 1, four groups (N=36) of restorative materials; (1) re sin composite (RSN), (2) resin-modified glass ionomer (RMGI), (3) conv entional glass ionomer (CGI), and (4) porcelain (PCN), were subjected to a rinse in either tap water (control) or Pyrromethene 556 dye at a concentration of 0.01M for 30 seconds or 0.0015M for 60 seconds. They were then rinsed with 25% ethanol as would be done in clinical usage. In Study 2, the same restorative materials (except PCN) were subjected to a rinse in either tap water (control) (N=8) or 0.0018M sodium fluo rescein (N=8) for 60 seconds followed by a 5-second rinse with tap wat er. For both studies the specimens were analyzed for overall color cha nges (Delta E) comparing baseline to immediately post dye exposure an d then again after 1, 4, 24, and 48-hour storage under running tap wat er. In addition, an image of each specimen, illuminated under an argon laser light (HGM), was captured with a miniature charged-coupled devi ce (CCD) color camera at the same time intervals when the color was me asured. These images were analyzed for fluorescence using computer ass isted methods. A software program then computed the mean and standard deviation of the fluorescence values for each image. The data were ana lyzed using repeated measures ANOVA. Results: Delta E values from bas eline on specimens treated with either Pyrromethene 556 or sodium fluo rescein were not significantly different from water at any time. The o nly exceptions were CGI specimens exposed to 0.01M Pyrromethene 556 an d RMGI exposed to sodium fluorescein which had a higher Delta E immed iately after treatment, however this effect was reversed after 1-hour rinse. Mean Delta E was less than 2.69 for specimens treated with Pyr romethene 556 and less than 3.20 for specimens treated with sodium flu orescein after 1-hour rinse in water. When the mean fluorescence level , as determined by the computer, was averaged there was no difference between the Pyrromethene 556 treatments and control for RMGI, RSN and PCN after 4-hour rinse in water and, as time in storage increased, the fluorescence level decreased. CGI treated with 0.01M Pyrromethene 556 was significantly more fluorescent even after 48-hour rinse in water. All specimens treated with sodium fluorescein were also significantly more fluorescent than control even after 48-hour rinse in water. It w as concluded that exposure of these restorative materials to Pyrrometh ene 556 at 0.01M or 0.0015 M or to 0.0018M sodium fluorescein will not lead to any prolonged visually detectable color changes.