Related Experiment Video
Updated: Nov 18, 2025
Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites
Published on: November 9, 2014
Effectiveness of in-office bleaching treatment with different activation techniques on tooth color changes and
Ozge Parlar Oz1, Nermin Demirkol2
1Department of Prosthodontics, Faculty of Dentistry, University of Gaziantep, Gaziantep, Turkey, ozgeparlar@gmail.com.
Purpose:
To investigate the effectiveness of different light activation methods for in-office bleaching agents in terms of color change durability and tooth sensitivity (TS).
Methods:
80 subjects were randomly divided into four groups (n= 20). A bleaching agent (40% H2O2) was activated using a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser, an 810-nm diode laser, a light-emitting diode (LED), and conventional (chemical) treatment. The CIE L*a*b* system and ΔE* values were used to measure color changes in the teeth using a spectrophotometer. TS was measured using the visual analogue scale (VAS). The measurements were performed before the treatment, immediately afterwards, and 2 weeks, 1 month, and 6 months later. A P< 0.05 was accepted as statistically significant.
Results:
The most statistically significant color change occurred in the 2nd week (⏊E2) in all groups (P< 0.05). However, the most color change in the 2nd week (ΔE2) occurred in the Nd:YAG group, yet there was no statistically significant result between Nd:YAG and LED (P< 0.05). After the procedure (VAS2), a statistically significant increase in TS was observed in all groups (P< 0.05), with the highest sensitivity observed in the LED group; significant differences were observed between the LED and the other groups (P< 0.05).
Clinical Significance:
Although all light activation techniques showed noticeable color changes, the conventional technique showed appreciable color change at the 6-month follow-up. Nd:YAG and diode laser activation can be preferable alternatives to LED and conventional activation in clinical practice as they bleach more and faster, decrease the number of sessions and chair time, and cause minimum sensitivity.
