Ultrasonic activation of internal bleaching agents

Area of Science:

• Endodontics
• Restorative Dentistry
• Dental Materials Science

Background:

• Internal bleaching is a common procedure for discolored teeth.
• Conventional internal bleaching involves placing bleaching agents within the pulp chamber.
• The use of ultrasonic activation aims to enhance the efficacy of bleaching agents.

Purpose of the Study:

• To investigate the effectiveness of ultrasonic activation of bleaching agents for ex vivo internal bleaching.
• To compare ultrasonic activation with conventional internal bleaching techniques.

Main Methods:

• Fifty human canine teeth were artificially stained and root-filled.
• Teeth were divided into five groups: sodium perborate (SP), carbamide peroxide (CP), CP with ultrasonic activation (CPUS), hydrogen peroxide (HP), and HP with ultrasonic activation (HPUS).
• Color change was measured using a dental spectrophotometer after two bleaching sessions, analyzing CIELab parameters (L*, a*, b*, ΔE*).

Main Results:

• No significant differences were found in ΔL*, Δa*, or ΔE* among the groups.
• A significant difference was observed in Δb* after both sessions.
• While HP and HPUS showed greater Δb* after the first session, HPUS demonstrated the highest Δb* after the second session, though similar to HP and SP.

Conclusions:

• Ultrasonic activation of bleaching agents does not enhance the effectiveness of ex vivo internal bleaching compared to conventional methods.
• The study suggests that conventional internal bleaching procedures are as effective as those with ultrasonic activation.