Colorimeter and scanning electron microscopy analysis of teeth submitted to internal bleaching.

Introduction: This in vitro study compared the tooth color and the ultrastructure of internal dental tissues before and after internal bleaching.

Methods: Sodium perborate was placed in the pulp chamber of endodontically treated molars and sealed with intermediate restorative material. The test samples were stored in a physiologic solution, and the bleaching agent was replaced every 7 days.