Photo-curable reparative material for dental use

• US 20030162863A1
• Filed: 03/18/2002
• Published: 08/28/2003
• Est. Priority Date: 07/19/2000
• Status: Active Grant

• Current Assignee: Tokuyama Corporation
• Original Assignee: Tokuyama Corporation
• Inventors: Satoh, Takeshi, Himeno, Masataka, Kazama, Hideki
• Granted Patent: US 6,849,670 B2
• Time in Patent Office: Days
• US Class Current: 523/109
• CPC Class Codes: A61K 6/62 Photochemical radical initiators
• CPC Class Codes: A61K 6/71 Fillers
• CPC Class Codes: A61K 6/887 Compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08L 27/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 33/04 Homopolymers or copolymers of esters C08L43/04 takes precedence

Abstract

A photocurable dental restorative comprising (i) 100 parts by weight of a polymerizable monomer, (ii) 0.01 to 5 parts by weight of a photopolymerization initiator of acylphosphine oxide, and (iii) 200 to 1900 parts by weight of an inorganic filler, wherein the inorganic filler (iii) is a mixed filler of:

(A) irregular-shaped inorganic particles having an average particle size of not smaller than 0.1 μm but smaller than 1 μm;

(B) spherical inorganic particles having an average primary particle size of not smaller than 0.1 μm but not larger than 5 μm; and

(C) fine inorganic particles having an average primary particle size of not larger than 0.1 μm;

which are so blended as to satisfy the following mass ratios {circle over (1)} to {circle over (3)}:

mA/(mB+mC)=0.2 to 3  {circle over (1)}

mB/(mB+mC)=0.5 to 0.99  {circle over (2)}

mC/(mB+mC)=0.01 to 0.5  {circle over (3)}

where mA, mB and mC are masses of the inorganic particles (A) to (C).

The restorative features excellent handling property, and makes it possible to obtain a cured product having a high fracture toughness and excellently glossy surface.

Claims

1. A photocurable dental restorative comprising (i) 100 parts by weight of a polymerizable monomer, (ii) 0.01 to 5 parts by weight of a photopolymerization initiator of acylphosphine oxide, and (iii) 200 to 1900 parts by weight of an inorganic filler, wherein the inorganic filler (iii) is a mixed filler of:

(A) irregular-shaped inorganic particles having an average particle size of not smaller than 0.1 μ

m but smaller than 1 μ

m;

(B) spherical inorganic particles having an average primary particle size of not smaller than 0.1 μ

m but not larger than 5 μ

m; and

(C) fine inorganic particles having an average primary particle size of not larger than 0.1 μ

m;

which are so blended as to satisfy the following mass ratios {circle over (1)} to {circle over (3)};

mA/(mB+mC)=0.2 to 3 

 

{circle over (1)}mB/(mB+mC)=0.5 to 0.99 

 

{circle over (2)}mC/(mB+mC)=0.01 to 0.5 

 

{circle over (3)}

where mA, mB and mC are masses of the inorganic particles (A) to (C).

2. A photocurable dental restorative according to claim 1, wherein said mixed filler (iii) is obtained by so blending the inorganic particles (A) to (C) as to satisfy the following mass ratios {circle over (1)}′

to {circle over (3)}′

;

mA/(mB+mC)=0.4 to 2.3 

 

{circle over (1)}′

mB/(mB+mC)=0.6 to 0.9 

 

{circle over (2)}′

mC/(mB+mC)=0.1 to 0.4 

 

{circle over (3)}′

.

3. A photocurable dental restorative according to claim 1, wherein in said mixed filler (iii), a maximum size of aggregates of primary particles of the spherical inorganic particles (B) and a maximum size of aggregates of primary particles of the fine inorganic particles (C) are not larger than 20 μ

m, respectively, and a total amount of the aggregates thereof is not larger than 20% by volume of the whole mixed filler (iii).

4. A photocurable dental restorative according to claim 1, wherein said spherical inorganic particles (B) have an average primary particle size of not larger than 1 μ

m.

5. A photocurable dental restorative according to claim 1, wherein said fine inorganic particles (C) have an average primary particle size of from 0.05 to 0.09 μ

m.

6. A photocurable dental restorative according to claim 1, wherein said mixed filler (iii) has a volume of the pores of not smaller than 0.08 μ

m due to strongly aggregated particles of not larger than 0.1 cc/g.

7. A photocurable dental restorative according to claim 1, wherein said mixed filler (iii) has at least one distribution peak at a position of a particle size of not larger than 0.1 μ

m and at a position of a particle size of not smaller than 0.1 μ

m but not larger than 1 μ

m, respectively, on particle size distribution based on the volume of particles, but has no distribution peak at a position of a particle size in excess of 5 μ

m.

8. A photocurable dental restorative according to claim 1, wherein said acylphosphine oxide is represented by the following general formula (I) or (II):

9. A photocurable dental restorative according to claim 1, wherein said irregular-shaped inorganic particles (A) are treated for their surfaces with a silane coupling agent represented by the following general formula (III),

10. A photocurable dental restorative according to claim 1, wherein an amine compound is contained in an amount of from 0.01 to 5 parts by weight per 100 parts by weight of the polymerizable monomer (i).

11. A method of producing a photocurable dental restorative by preparing an inorganic filler by mixing:

(A) irregular-shaped inorganic particles having an average particle size of not smaller than 0.1 μ

m but smaller than 1 μ

m;

(B) spherical inorganic particles having an average primary particle size of not smaller than 0.1 μ

m but not larger than 5 μ

m; and

(C) fine inorganic particles having an average primary particle size of not larger than 0.1 μ

m;

so as to satisfy the following mass ratios {circle over (1)} to {circle over (3)};

mA/(mB+mC)=0.2 to 3 

 

{circle over (1)}mB/(mB+mC)=0.5 to 0.99 

 

{circle over (2)}mC/(mB+mC)=0.01 to 0.5 

 

{circle over (3)}

where mA, mB and mC are masses of the inorganic particles (A) to (C),

and by mixing 100 parts by weight of a polymerizable monomer, 0.01 to 5 parts by weight of a photopolymerization-initiator of acylphosphine oxide, and 200-to 1900 parts by weight of said inorganic filler.