Light-activated bleaching: effects on surface mineral change on enamel

Area of Science:

• Dental materials science
• Biomaterials
• Conservative dentistry

Background:

• Dental bleaching with hydrogen peroxide (HP) is a common cosmetic procedure.
• The effect of light curing units (LCUs) on enamel integrity during bleaching requires further investigation.
• Understanding potential surface changes is crucial for safe and effective dental treatments.

Purpose of the Study:

• To evaluate the in vitro effect of 35% HP on bovine enamel surface microhardness and topography.
• To compare the impact of Quartz Tungsten-Halogen (QTH) and Light Emitting Diode (LED) LCUs when activating 35% HP.
• To assess the safety of 35% HP bleaching with different LCUs on enamel mineral content.

Main Methods:

• Bovine enamel blocks were subjected to microhardness testing.
• Groups were treated with 35% HP, with or without QTH or LED activation.
• Microhardness was measured immediately, 7, and 14 days post-treatment; SEM was used for surface analysis.

Main Results:

• No significant differences in enamel microhardness were observed between the control and treated groups at any time point.
• Scanning electron microscopy (SEM) revealed no significant surface alterations attributable to the bleaching treatments.
• The mineral content of the enamel remained unaffected by 35% HP, regardless of LCU activation.

Conclusions:

• 35% HP bleaching, whether activated by QTH or LED LCUs, does not adversely affect enamel surface topography.
• The mineral content of dental enamel is not compromised by 35% HP bleaching with QTH or LED activation.
• These findings suggest that 35% HP bleaching with QTH or LED LCUs is a safe procedure for dental enamel in vitro.