Preformed dental composite crown, process of production and use thereof

Patent metadata

Field	Value
Publication number	US-11534264-B2
Application number	US-202016813024-A
Country	US
Kind code	B2
Filing date	Mar 9, 2020
Priority date	Mar 7, 2016
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

The invention relates to a preformed dental composite crown being characterized by its shape and chemical composition, the shape being characterized as follows: having an occlusal top surface and depending buccal, mesial, distal and lingual side surfaces, the side surfaces being connected to each other and forming a crown cervix, the wall thickness of the crown at the crown cervix being lower than 0.6 mm; at least two of opposing depending side surfaces having a concave shape; the chemical composition of the material the preformed dental composite crown is made of being a hardened composition comprising the following components: nano-filler(s) in an amount from 20 to 70 wt. %, resin matrix in an amount from 20 to 75 wt. %, wt. % with respect to the weight of the chemical composition, the resin matrix comprising urethane(meth)acrylate(s) and (meth)acrylate(s) not comprising a urethane moiety.The invention also relates to a kit of parts comprising such a preformed dental composite crown, processes for producing such crowns and the use of such a crown for treating a dental tooth.

First claim

What is claimed is:

1. A process of producing a preformed dental composite crown by milling the preformed dental composite crown out of a milling block, the process comprising the steps of
providing a composite milling block,
the chemical composition the composite milling block is made of comprising the following components:
nano-filler(s) in an amount from 20 to 70 wt. %,
resin matrix in an amount from 20 to 75 wt. %,
wt. % with respect to the weight of the chemical composition,
the resin matrix comprising urethane(meth)acrylate(s) and (meth)acrylate(s) not comprising a urethane moiety;

milling the preformed dental composite crown out of the composite milling block,
the shape of the preformed dental composite crown being characterized as follows:
for molars and premolars having an occlusal top surface and depending buccal, mesial, distal and lingual, respectively palatinal side surfaces,
for anterior teeth and incisors having a distal top surface and depending labial, mesial, distal and lingual, respectively palatinal side surfaces,
the side surfaces being connected to each other and forming a crown cervix,
the wall thickness of the crown at the crown cervix being lower than 0.6 mm;
at least two of opposing depending side surfaces having a concave shape.

2. The process of claim 1 , the shape of the preformed dental composite crown being further characterized by at least one or more or all of the following features:
wall thickness of the side surfaces of the crown: not exceeding 0.6 mm;
wall thickness of the side surfaces of the crown: from 0.1 to 0.4 mm;
wall thickness of the top surface of the crown: from 0.15 mm and 1.5 mm;
undercut: more than 0.2 mm.

3. The process of claim 1 , the nano-filler(s) of the chemical composition the composite milling block is made of comprising particles of SiO 2 , ZrO 2 , Al 2 O 3 or mixtures thereof.

4. The process of claim 1 , the nano-filler(s) of the chemical composition the composite milling block is made of comprising aggregated, agglomerated, discrete nano-sized particles or mixtures thereof.

5. The process of claim 1 , the urethane(meth)acrylate(s) of the chemical composition the composite milling block is made of being characterized as follows:
having the structure A—(S1—U—S2—MA) n , with
A being a connector element comprising at least one unit,
S1 being a spacergroup comprising at least 4 units connected with each other,
S2 being a spacergroup comprising at least 4 units connected with each other,
the units of A, S1 and S2 being independently selected from —CH 2 —, —O—, —S—, —NR 1 —, —CO—, —CR 1 ═,

—N═, —CR 1 R 2 —,
with R 1 and R 2 being independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl, wherein these units can form linear, branched or cyclic structures such as alkyl, cycloalkyl, aryl, ester, urethane or amide groups,
U being a urethane group connecting spacergroups S1 and S2,
MA being an acrylate or methacrylate group and
n being 3 to 6.

6. The process of claim 1 , the chemical composition the composite milling block is made of comprising
Nano-filler(s) selected from aggregated, agglomerated or discrete nanoparticles and mixtures thereof in an amount from 20 to 70 wt. %,
Urethane(meth)acrylate(s) in an amount from 3 to 20 wt. %,
(Meth)acrylate(s) not comprising a urethane moiety in an amount from 5 to 55 wt. %,
wt. % with respect to the weight of chemical composition of the dental composite crown.

7. The process of claim 1 , the chemical composition the composite milling block is made of being characterized by either of the following parameters or combinations thereof:
flexural strength: from 50 to 200 MPa or from 80 to 150 MPa determined according to ISO 4049:2009,
E-modulus: from 1,000 to 4,000 MPa determined according to ISO 4049:2009 in combination with DIN EN 843-2:2007;
impact strength: from 5 to 15 kJ/m 2 determined according to DIN 53453:175-05,
abrasion: less than about 20 or less than 15 or less than 10 mm 3 ,
color: being tooth colored.

8. The process of claim 1 , the shape of the dental composite crown being characterized as follows:
for molars and premolars having an occlusal top surface and depending buccal, mesial, distal and lingual, respectively palatinal side surfaces,
for anterior teeth and incisors having a distal top surface and depending labial, mesial, distal and lingual, respectively palatinal side surfaces,
the side surfaces being connected to each other and forming a crown cervix,
the wall thickness of the crown at the crown cervix being from 0.1 to 0.4 mm,
wall thickness of the top surface being from 0.15 mm to 1.5 mm,
at least two of opposing depending side surfaces having a concave shape resulting in an undercut design larger than 0.2 mm,
the chemical composition of the milling block being characterized by comprising the following components:
nano-filler(s) in an amount from 20 to 70 wt. %,
resin matrix in an amount from 20 to 75 wt. %,
the resin matrix comprising the polymerization product of
urethane(meth)acrylate(s) having at least 2 polymerizable moieties in an amount from 3 to 20 wt. % and
(meth)acrylate(s) having at least 2 polymerizable moiety but not comprising a urethane moiety in an amount from 5 to 55 wt. %,
wt. % with respect to the weight of the chemical composition,

the chemical composition being characterized by the following parameters:
impact strength: from 5 to 15 kJ/m 2 determined according to DIN 53453:175-05,
E-modulus: from 1,000 to 4,000 MPa determined according to ISO 4049:2009 in combination with DIN EN 843-2:2007.

9. The process of claim 1 , the milling being done by a dental practitioner during the treatment of a patient.

10. The process of claim 1 , comprising the further step of adapting the shape of the preformed dental composite crown by cutting or grinding.

11. The process of claim 1 , comprising the further step of roughening a part of the surface of the preformed dental composite crown.

12. The process of claim 11 , the roughening being done by sandblasting.

Assignees

• 3M Innovative Properties Company

Inventors

• Herrmann Andreas
• Schechner Gallus
• Hecht Reinhold
• Mayr Helmar B
• Korten Malte
• Hofmann Bernhard
• Raia Gioacchino
• Meurer Till

Classifications

• A61C5/73 Primary

  Composite crowns · CPC title

• A61K6/849

  comprising inorganic cements · CPC title

• A61C5/77

  Methods or devices for making crowns · CPC title

• A61K6/802

  comprising ceramics · CPC title

• A61K6/893 Primary

  Polyurethanes · CPC title