Effective tooth-bleaching protocols capable of reducing H(2)O(2) diffusion through enamel and dentine

Area of Science:

• Dental materials science
• Biomaterials engineering
• Conservative dentistry

Background:

• Tooth bleaching is a common aesthetic procedure.
• Hydrogen peroxide (HP) and carbamide peroxide (CP) are widely used bleaching agents.
• Understanding the diffusion of bleaching agents through dental tissues is crucial for safety and efficacy.

Purpose of the Study:

• To evaluate how different experimental protocols affect tooth bleaching effectiveness.
• To assess the impact of these protocols on hydrogen peroxide (HP) diffusion through enamel and dentine.

Main Methods:

• Enamel/dentine discs underwent six bleaching sessions with varying HP (17.5%, 35%) or CP (37%) concentrations, application frequencies, and durations.
• Color change (ΔE) was measured after each session.
• HP diffusion was quantified using artificial pulp chambers at specific intervals.

Main Results:

• All tested bleaching protocols increased tooth color change (ΔE).
• Specific protocols (17.5%-HP 3x15min, 35%-HP 1x15min, 35%-HP 3x5min) showed reduced HP diffusion with comparable ΔE to the control.
• Carbamide peroxide (CP) at 37% for 3x20min demonstrated HP diffusion similar to the positive control.

Conclusions:

• Reducing HP concentration or application time results in gradual tooth whitening and decreased HP diffusion.
• Lowering HP concentration to 17.5% or shortening application time significantly improves bleaching while reducing diffusion.
• These modified protocols represent viable alternatives for clinical tooth bleaching.