METHOD OF PRODUCING HYDROXYLAPATITE-BASED HYBRID CERAMICS AS MODEL OF DENTAL HARD TISSUES Russian patent published in 2024 - IPC A61K6/802 C04B35/447 C04B35/622 C04B41/83 G09B23/28 

FIELD: medicine; dentistry.

SUBSTANCE: invention relates to a method of producing hybrid ceramics as a model of dental hard tissues for laboratory in vitro tests of dental materials. To obtain a hydroxylapatite-based hybrid ceramic by frozen casting technology, consisting of a hydroxylapatite (HA) frame with impregnation with a polymer, preparing an aqueous suspension in a ratio of HA powder: water 0.5–0.6:1, continuously stirring for 2–3 hours, then, without interrupting mixing, lithium carbonate is added to the suspension in amount of 0.4–0.5 wt.% and 35% aqueous solution of polyacrylic acid (PAA) in amount of 2–4 wt.%. Obtained suspension is poured into molds, frozen at temperature from −5 to −20 °C with subsequent freeze drying. Samples obtained from the molds are sintered in a dental vacuum furnace at a firing temperature of up to 1,120 °C and a temperature rise rate of 10–15 °C/min. Sintered porous samples are impregnated with monomer-oligomer composition, consisting of urethane dimethacrylate, triethylene glycol dimethacrylate and ethylene glycol monomethacrylate, with the addition of benzoyl peroxide (BP) as a polymerisation initiator and polymerised at temperature of 95 °C for 30 minutes to form a polymer matrix in the pores of the HA structure.

EFFECT: use of the invention provides an increase in the strength at diametrical compression of the hybrid hydroxylapatite ceramic compared to the prototype; wherein the created model samples have a low water absorption index and, accordingly, are close to natural tooth tissues in terms of ability to staining with food dyes.

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