Color changes of restorative materials exposed in vitro to cola beverage.

Purpose: The purpose of this in vitro study was to evaluate the color stability of restorative materials when exposed to a cola beverage.

Methods: Color changes in restorative materials caused by exposure to a cola beverage were studied using a split-plot experimental design. Three restorative materials (composite, resin-modified glass ionomer cement, and compomer) and 3 shades of each material under 2 surface conditions (polished and unpolished) were studied.