To determine if any factors exist which may affect long term color stability of bleached teeth.
- Bleaching of N=43 discolored RCT teeth attempted
- inclusion: satisfactory RCT, minimal coronal restoration, no amalgam
- history and records obtained
- pre-op shade determined via shade guide in daylight and operatory light
- pumiced external stains, rubber dam, lingual access, gutta percha removed 2 mm from CEJ and placed zinc phosphate cement to CEJ, etched dentin with phosphoric acid, applied etOH and CCL3, warm 30% H202 soaked cotton pellet in access and activated with UV light for 2 minutes, repeated 2-3x, cotton pellet soaked H202 in chamber with ZOE placed for 24 hours, repeated until desired shade achieved
- 91% of teeth bleached had same or lighter color than adjacent teeth
- 84% recall rate 1yr, 44% recall 2yr
- No correlation between bleach success and: age, rate of discoloration, length of time discolored, and degree of
- Teeth that took more appointments to bleach were more liable to re-discolor
Internal bleaching has high success, although ~50% will have some color regression.