Calcium Peroxide for Teeth: Side Effects & Risks - What You Need to Know

Calcium peroxide (CaO₂) is used in some professional and OTC dental whitening products as an oxygen-releasing bleaching agent. It breaks down to calcium hydroxide and hydrogen peroxide.

Potential Side Effects

• Gingival / Soft Tissue Irritation: Chemical burn from peroxide exposure—white sloughing, soreness.
• Tooth Sensitivity: Transient dentinal hypersensitivity to thermal, tactile, or osmotic stimuli (usually resolves in 1–4 days).
• Mucosal Burning / Stinging: Especially if tray overextends or gel contacts lips/cheeks.
• Enamel Surface Changes: Excessive/prolonged use may alter enamel microstructure (increased porosity, reduced microhardness).
• Pulpal Irritation: Deep penetration in thin enamel/cracked teeth → irreversible pulpitis risk.
• Allergic Reaction: Rare; contact dermatitis to peroxide or tray material.
• Increased Caries Risk: If used incorrectly (e.g., high frequency, poor hygiene), demineralization may outweigh remineralization.

Risk Mitigation

• Use only as directed by dentist or product instructions.
• Custom-fitted trays minimize gingival contact.
• Desensitizing toothpaste (KNO₃, SnF₂) 2 weeks before/during treatment.
• Fluoride gel/tray after whitening enhances remineralization.
• Limit treatment duration/frequency per protocol.
• Discontinue if severe pain, ulceration, or swelling occurs.

Contraindications

• Pregnancy / lactation (insufficient data)
• Active caries, cracked teeth, leaking restorations
• Severe gingivitis / periodontitis (treat first)
• Peroxide allergy
• Age <16 (pulp chambers large, sensitivity high)

Professional supervision ensures proper diagnosis, tray fit, concentration selection, and monitoring.