CN119430910 — Piezoelectric Ceramic Powder for Whitening and Mineralizing Teeth

CN119430910 is a Chinese patent titled "Piezoelectric ceramic powder for whitening and mineralizing teeth as well as preparation method and application of piezoelectric ceramic powder." It is the primary patent reproduced in the Min Xing et al. dossier (Min Xing et al., Sr-Ca-Ba-TiO₃ Toothpaste: Whitening and Remineralization Dossier) and the document that defines the BSCT (Ba₀.₉Sr₀.₀₅Ca₀.₀₅TiO₃) material and its preparation.

Stated purpose

The patent states its purpose as providing "a convenient and long-lasting piezoelectric ceramic powder for promoting teeth whitening and mineralization repair, as well as its preparation method and application." It frames the invention as avoiding "tooth damage caused by excessive use of bleaching agents during teeth whitening" by generating active oxygen under ultrasonic or mechanical stimulation instead.

Preparation method (preserved as given)

(1) Based on the chemical formula Ba(1-2x)Sr(x)Ca(x)TiO3,
    weigh barium acetate (99% purity), calcium acetate (99% purity),
    and strontium acetate (98% purity) according to the molar ratio
    of (1-2x):x:x, dissolve them in acetic acid, then mix them evenly
    at 60-90 °C for 30 min, and then cool them naturally to room
    temperature to obtain solution A;

(2) Dissolve tetrabutyl titanate in 1 mL of acetylacetone and 9 mL
    of ethylene glycol methyl ether according to the stoichiometric
    ratio to form homogenized solution B;

(3) Mix and stir solutions A and B for 5 hours and age for 24 to 96
    hours to form homogenized solution C, and then dry it at 90 to
    150 °C to form dry sol;

(4) The dry sol was heat-treated at 600-1200 °C (heating rate
    5 °C/min) for 2h to form BaSrCaTiO3-based ceramic powder (BSCT).

Preferred embodiment parameters:

• Step (1): x = 0.05, stirring temperature 70 °C
• Step (3): aging time 72 hours, drying temperature 120 °C
• Step (4): heat treatment temperature 900 °C

The worked example in the dossier specifies 30 mL of acetic acid, magnetic stirring at 70 °C for 30 min, drying of homogenized solution C at 120 °C for 24 h, and calcination at 900 °C at 5 °C/min for 2 h.

Claimed beneficial effects

The patent lists three:

1. The powder "can respond efficiently to external ultrasonic stimulation and generate active oxygen with strong oxidizing ability (such as superoxide anion, hydrogen peroxide, etc.)" that can "effectively decompose and remove stains on the tooth surface, such as coffee stains, tea stains, tobacco stains, etc."
2. The Ca and Sr ions "can promote the mineralization and repair of the tooth surface, thereby enhancing the hardness and anti-caries ability of the teeth."
3. The powder "has good biocompatibility, ensuring its safety in the oral environment and the feasibility of long-term use."

Reported supporting observations

• Particle size approximately 80 nm; Ti, Ba, Ca, O and Sr uniformly distributed.
• Butterfly-shaped displacement–voltage and phase curves indicating piezoelectric hysteresis.
• Superoxide and hydroxyl radical peaks captured after ultrasonic treatment.
• Indigo carmine decolorization at 2 W ultrasound over 40 min, with decreasing absorbance at 600 nm.
• SEM crystalline deposits on enamel and dentin; weak hydroxyapatite XRD peaks.
• Fibroblast extract test at 1 mg/mL BSCT, extract collected after 48 h.

Caveats

The patent is a claim document, not a test report. Its beneficial-effect statements are the applicant's assertions; the dossier does not include independent validation, wear data, long-term safety data, or community-level microbiological data. See Patent as Evidence and BSCT Claims vs. Evidence: The Tooth Powder Dossier Without Clinical Data.

The patent text also contains the garbled string "BaSrCaTiO_NER12," likely an OCR artifact.