Comparative evaluation to composite resin bleaching using ozone-enhanced low-concentration hydrogen peroxide.

Area of Science:

• Dental Materials Science
• Biomaterials Research
• Aesthetic Dentistry

Background:

• Composite resins are widely used in aesthetic dentistry but are susceptible to staining from common beverages like tea.
• Bleaching agents are employed to restore the shade of stained dental restorations, with hydrogen peroxide being a common choice.
• Ozone therapy is explored as a potential adjunct or alternative for dental material bleaching due to its oxidative properties.

Purpose of the Study:

• To compare the effectiveness of low-concentration hydrogen peroxide (7%HP) followed by ozone with high-concentration hydrogen peroxide (30%HP) alone for bleaching tea-stained composite resin.
• To evaluate the bleaching efficacy of ozone alone compared to 7%HP and 30%HP alone.
• To assess the impact of different bleaching protocols on the color stability and shade values of composite resin.

Main Methods:

• A controlled randomized laboratory study involving 80 tea-stained composite resin discs.
• Four bleaching groups were established: ozone alone, 7%HP alone, 7%HP followed by ozone, and 30%HP alone.
• Shade assessment utilized VITA classic and 3D Master shade guides, Easyshade Spectrophotometer, and Rayplicker Handy spectrophotometer measuring CIELab values (L*, a*, b*) and color differences (ΔE₀₀, ΔEab).

Main Results:

• Ozone alone demonstrated the least effective bleaching of stained composite resin compared to all other tested protocols (P < .05).
• No significant difference in shade change was observed between 7%HP followed by ozone and 30%HP alone (P > .05).
• While 30%HP alone resulted in a higher L* value, overall color differences (ΔE₀₀ and ΔEab) were not significantly different between the 7%HP and ozone combination and 30%HP alone.

Conclusions:

• Combining 7%HP with ozone provides comparable bleaching outcomes to 30%HP alone for tea-stained composite resin.
• Ozone alone is significantly less effective for bleaching composite resin compared to hydrogen peroxide-based protocols.
• The sequential application of low-concentration hydrogen peroxide followed by ozone presents a viable alternative to high-concentration hydrogen peroxide for stain removal in composite restorations.