Dental composite material

Abstract

The invention relates to a polymerisable dental composite material comprising (i) 40 to 90% by weight of an inorganic filler component comprising at least one dental glass, as well as optionally at least one an amorphous metal oxide, (ii) 10 to 60% by weight of at least one urethane (alkyl) acrylate of the idealised formula I, (iii) 0.01 to 15% by weight of at least one di-, tri-, tetra- or multi-functional monomer not being a urethane (alkyl) acrylate, (iv) 0.01 to 10% by weight of at least one initiator, of an initiator system, as well as optionally of at least one stabiliser, and optionally of at least one pigment, the total composition of the composite material amounting to 100% by weight, as well as to a polymerised composite material for producing direct dental restorations or indirect dental restorations.

Claims

1. Polymerisable dental composite material, comprising: (i) an inorganic filler component comprising: (i.1) 70 to 84% by weight of at least one dental glass, wherein a) the dental glass has an average particle size d.sub.50 of 1.8 m, or b) the dental glass comprises a mixture of dental glasses having an average particle size, with i) d.sub.50 of 2 to 8 m, ii) d.sub.50 of 1.0 to 2.0 m, and iii) d.sub.50 of 0.5 m to 2 m, the fractions of i) to ii) to iii) being present in a ratio of 1 to 4:1:4 to 8, and (i.2) 2 to 10% by weight amorphous metal oxide, (ii) a mixture of at least three different urethane acrylates, the mixture comprising 10 to 18% by weight of at least one urethane acrylate having a bivalent alicyclic group of the idealised formula I ##STR00007## and/or mixtures of said urethanes of formula I, as well as optionally mixtures of the isomers of the afore-mentioned compounds with R.sup.1 and R.sup.2 each independently selected from H and alkyl having 1 to 8 C-atoms, and 3 to 8% by weight of at least one further di-functional urethane acrylate and/or urethane (alkyl) acrylate having a bivalent alkylene group and not satisfying formula I, and 0.2 to 2% by weight of at least one at least tetra-functional dendritic urethane methacrylate comprising tetra- to deca-functional dendritic urethane methacrylates, (iii) 0.01 to 2% by weight of at least one substance selected from the group consisting of di-methacrylic esters of polyethers, tri-, tetra- or multi-functional methacrylic esters of polyethers and bis-(2-oxa-3-oxo-pentyl-4-ene) tetrahydrodicyclopentadiene and isomers thereof, (iv) 0.01 to 10% by weight of at least one initiator, of an initiator system, as well as optionally of at least one stabiliser, and optionally of at least one pigment, wherein each % by weight is based on a total weight of the composite material, the total weight of the composite material amounting to 100% by weight.

2. Dental composite material according to claim 1, wherein the at least one dental glass has an average particle size d.sub.50 of 0.5 to 10 m.

3. Dental composite material according to claim 1, wherein the amorphous metal oxide comprises at least one non-agglomerated amorphous metal oxide having a primary particle size of 2 to 150 nm, and the amorphous metal oxide optionally comprising precipitated silicon oxide, pyrogenic silica, zirconium oxide or mixed oxides.

4. Dental composite material according to claim 1, wherein the at least one stabiliser comprises water, at least one benzophenone derivative and/or at least one phenol derivative.

5. Dental composite material according to claim 1, wherein it further comprises (v) 0.01 to 15% by weight of a polymeric particulate filler, the total composition of the composite material amounting to 100% by weight.

6. Polymerised dental composite material obtainable by polymerising the composite material according to claim 1, i) using a UV- and/or VIS-radiation source having emission maxima in the spectral range of 400 nm to 530 nm, and/or ii) at a pressure of 50 to 300 MPa and/or iii) at an elevated temperature of 90 to 150 C.

7. Polymerised dental composite material according to claim 6, comprising: (ii) at least one polymer based on the mixture, wherein the mixture comprises: 3 to 8% by weight of the at least one further di-urethane acrylate having a bivalent alkylene group and not satisfying formula I, and (iv) 0.01 to 10% by weight of the at least one pigment, and of at least one organic dying pigment and/or at least one inorganic dying pigment, wherein each % by weight is based on a total weight of the composite material, the total composition weight of the composite material amounting to 100% by weight.

8. Polymerised dental composite material according to claim 6, wherein the polymerised dental composite material is present in the form of a block of material, wherein the block of material is present as three-dimensional geometric form body.

Description

(1) FIG. 1a: Cross section of the test specimen, FIG. 1b: Top view onto the test specimen. With legend of refence numerals and labellings and description of the measurement setup.

LEGEND

(2) w=distance between the center point of the two holes and the opposite test specimen edge; B=width of the entire test specimen; l.sub.1=length; l.sub.2=distance between the center point of the two holes being symmetrically arranged to the crack plane +/0,005w; B=thickness R=radius; a=crack length; P=force
B=1.25w+/0.01w;l.sub.1=1.2w+/0.01w,l.sub.2=0.55w+/0.0005w,R=0.125w+/0.005w,0.4w<h<0.6w;0.45wa0.55w

(3) The pins and holes are intended to have a smooth surface and a loose fit to avoid friction.

(4) $K_{\mathrm{Ic}}=\left[P/h.Math.W^{0.5}\right]f\left(a_i/W\right)$$f\left(a_i/W\right)=\frac{\begin{array}{c}\{\left(2+\frac{a_i}{W}\right)[0.886+4.64\left(\frac{a_i}{W}\right)-\\ 13.32{\left(\frac{a_i}{W}\right)}^2+14.72{\left(\frac{a_i}{W}\right)}^3-5.6{\left(\frac{a_i}{W}\right)}^4]\}\end{array}}{{\left(1-\frac{a_i}{W}\right)}^{3/2}}$

(5) Thereafter, the test specimens are fixed in a universal testing machine (Zwick/Roell) using metallic pins that are guided through the holes. Subsequently, a defined tensile force (P) is applied via the pins the to the test specimen until break at a speed of 1 mm/min. The tensile force (P), the thickness (B) and the width (W) as well as the crack length a.sub.i, the fracture toughness K.sub.lc are calculated according to the following formula.

(6) TABLE-US-00001 TABLE 1a Compositions according to the invention Examples 1 to 2 Example 1 Example 2 dental glass average diameter 1.8 m 1.5 m d.sub.50 = 1.8 m or 1.5 m d.sub.99 < 20 m wt.-% g wt.-% g dental glass barium aluminum borofluor 75-78 75-78 66-70 66-70 silicate glass (silanised) metal oxide amorphous SiO.sub.2 4.5-5 4.5-5 5-6 5-6 urethane bis-(2,7-dioxa-3,8-dioxo-4-aza- 11-13 11-13 14-15 14-15 (meth)-acrylate decyl-9-ene) tetrahydro- dicyclopentadiene urethane methacrylate 0.5-0.7 0.5-0.7 0.6-0.8 0.6-0.8 dendrimer, hexa-functional 7,7,9-trimethyl 4,13-dioxo-3,14- 4-5 4-5 5-5.5 5-5.5 dioxa-5,12-diaza- hexadecane 1,16-diyl bismethacrylate di- to multi- dimethacrylate triethylene 1.0-1.1 1.0-1.1 1.2-1.3 1.2-1.3 functional glycol monomers initiator camphorquinone 0.02 0.02 0.02 0.02 system N,N-dimethyl 0.07 0.07 0.08 0.08 4-aminobenzoic acid ester, such as 2-n-butoxaethyl ester stabiliser 6-bis(1,1-dimethyl-ethyl) 0.04 0.04 0.04 0.04 4-methyl phenol pigments 0.1-0.6 0.1-0.6 0.1-0.6 0.1-0.6

(7) TABLE-US-00002 TABLE 1b Compositions according to the invention Examples 3 to 5 Example 3 Example 4 Example 5 dental glass average diameter d.sub.50 0.85 m 0.85 m 0.85 m wt.-% g wt.-% g wt.-% g dental glass barium aluminium 74.00% 74 75.60% 75.6 72.36% 72.36 borofluor silicate glass (silanised) metal oxide amorphous SiO.sub.2 5.00% 5 4.70% 4.7 5.32% 5.32 urethane bis-(2,7-dioxa-3,8- 12.80% 12.8 12.28% 12.28 14.00% 14 (meth)- dioxo-4-aza-decyl-9- acrylate ene) tetrahydro- dicyclopentadiene urethane 0.65% 0.65 0.58% 0.58 0.67% 0.67 methacrylate oligomer hexa- functional 7,7,9-trimethyl 4.50% 4.5 4.55% 4.55 5.19% 5.19 4,13-dioxo-3,14- dioxa-5,12-diaza- hexadecane 1,16-diyl bismethacrylate di- to multi- 1,2-bis(2-(methacryl- 0.85% 0.85 0.87% 0.87 1.00% 1 functional oyloxy)ethoxy)ethane monomers initiator tert.-butyl peroxy-2- 0.50% 0.5 0.41% 0.41 0.40% 0.4 system ethyl hexanoate stabiliser 2-hydroxy-4-methoxy- 0.30% 0.3 0.25% 0.25 0.28% 0.28 benzophenone water 0.70% 0.7 0.66% 0.66 0.64% 0.64 pigments organic/inorganic 0.70% 0.7 0.1% 0.1 0.14% 0.14 pigments (e.g. TiO.sub.2)

(8) TABLE-US-00003 TABLE 1c Compositions according to the invention Examples 6 to 8 Example 6 Example 7 Example 8 dental glass average diameter 0.85 m 0.85 m 2.0 m d.sub.50 and d.sub.99 <20 m wt.-% g wt.-% g wt.-% dental glass barium aluminium borofluor 75-78 75-78 66-70 66-70 silicate glass (silanised) feldspar 66-70 metal oxide amorphous SiO.sub.2 4.5-5 4.5-5 5-6 5-6 5-6 urethane bis-(2,7-dioxa-3,8-dioxo- 11-13 11-13 14-15 14-15 14-15 (meth)- 4-aza-decyl-9-ene) acrylate tetrahydro- dicyclopentadiene urethane methacrylate 0.5-0.7 0.5-0.7 0.6-0.8 0.6-0.8 0.6-0.8 dendrimer, hexa-functional 7,7,9-trimethyl 4,13-dioxo- 4-5 4-5 5-5.5 5-5.5 5-5.6 3,14-dioxa-5,12-diaza- hexadecane 1,16-diyl bismethacrylate di- to multi- 1,2-Bis(2-(methacryl- 1.0-1.1 1.0-1.1 1.2-1.3 1.2-1.3 1.2-1.4 functional oyloxy)ethoxy)ethane monomers (TEGDMA) initiator tert.-butyl peroxy-2-ethyl 0.37 system hexanoate camphorquinone 0.2 0.2 0.2 0.2 N,N-dimethyl 0.07 0.07 0.08 0.08 4-aminobenzoic acid ester, such as 2-n-butoxaethyl ester stabiliser 2-hydroxy-4-methoxy- 0.04 0.04 0.04 0.04 0.04 benzophenone water 0.6 pigments e.g. TiO.sub.2 0.1-0.6 0.1-0.6 0.1-0.6 0.1-0.6 0.1-0.6

(9) TABLE-US-00004 TABLE 1d Compositions according to the invention Examples 9 and 10 Example 9 Example 10 dental glass average diameter 0.85 m 0.85 m d.sub.50 0.85 m and d.sub.99 < 20 m wt.-% g wt.-% g dental glass barium aluminium borofluor silicate 40 40 79 79 glass (silanised) metal oxide amorphous SiO.sub.2 5 5 5 5 urethane bis-(2,7-dioxa-3,8-dioxo-4-aza-decyl- 46.80 46.80 7.8 7.8 (meth-) 9-ene) tetrahydrodicyclopentadiene acrylate urethane methacrylate dendrimer, 0.65 0.65 0.65 0.65 hexa-functional 7,7,9-trimethyl 4,13-dioxo-3,14-dioxa- 4.5 4.5 4.5 4.5 5,12-diaza-hexadecane 1,16-diyl bismethacrylate di- to multi- 1,2-bis(2-(methacryloyloxy) ethoxy) 0.85 0.85 0.85 0.85 functional ethane (TEGDMA) monomers initiator system tert.-butyl peroxy-2-ethyl hexanoate 0.5 0.5 0.5 0.5 camphorquinone 0.2 0.2 0.2 0.2 N,N-dimethyl-4-aminobenzoic acid 0.16 0.16 0.16 0.16 ester, such as 2-n-butoxaethyl ester stabiliser 2-hydroxy-4-methoxy-benzophenone 0.30 0.30 0.30 0.30 water 0.50 0.50 0.50 0.50 pigments e.g. TiO.sub.2 0.7 0.7 0.7 0.7

(10) TABLE-US-00005 TABLE 2 Comparative examples (VG) 1 to 2 VG 1 VG 2 dental glass average diameter 1.8 m 1.8 m d.sub.50 = 1.8 m and d.sub.99 < 20 m wt.-% g wt.-% g dental glass barium aluminium 75-78 75-78 66-70 66-70 borofluor silicate glass (silanised) metal oxide amorphous SiO.sub.2 4.5-5 4.5-5 5-6 5-6 d.sub.50 = 20 nm urethanr methacrylate 0.5-0.7 0.5-0.7 0.6-0.8 0.6-0.8 dendrimer, hexa-functional 7,7,9-trimethyl 4,13-dioxo-3,14-dioxa- 4-5 4-5 5-5.5 5-5.5 5,12-diaza-hexadecane 1,16-diyl bismethacrylate di- to multi- dimethacrylate triethylene glycol 1.0-1.1 1.0-1.1 1.2-1.3 1.2-1.3 functional bs-(2-oxa-3-oxo-pentyl-4-ene) 11-13 11-13 14-15 14-15 monomers tetrahydrodicyclopentadiene initiator camphorquinone 0.02 0.02 0.02 0.02 system N, N-dimethyl 4-aminobenzoic 0.07 0.07 0.08 0.08 acid ester, such as 2-n-butoxaethyl ester stabiliser 2,6-bis(1,1-dimethyl ethyl) 0.04 0.04 0.04 0.04 4-methyl phenol pigments 0.1-0.6 0.1-0.6

(11) TABLE-US-00006 TABLE 3 Comparative example (VG) 3 as VG3a to d in variation within the indicated ranges VG 3 dental glass average diameter 0.85 m d.sub.50 = 0.85 m, d.sub.99 = < 5 m wt.-% g dental glass barium aluminium borofluor silicate glass 62-80 62-80 (silanised) metal oxide amorphous SiO.sub.2, d.sub.50 = 5-10 nm 6.2-8.1 6.2-8.1 bis-GMA 11.8-16.2 11.8-16.2 dimethacrylate triethylene glycol 5.4-7.4 5.4-7.4 camphorquinone 0.03 0.03 di- to multi-functional N,N-dimethyl 4-aminobenzoic acid ester, 0.04 0.04 monomers such as 2-n-butoxaethyl ester stabiliser 2,6-bis(1,1-dimethyl ethyl) 4-methyl phenol 0.03-0.12 0.03-0.12 pigments 0.1-0.2 0.1-0.2

(12) Irradiation method of the surface of the test specimens with blue light (emission maximum approx. 440 to 460 nm) with 5 projection surfaces on the surface of the test specimen with respectively 120 seconds of the samples in Table 4. Thermal curing for further polymerisation indicated in Table 4 was carried out for approx. 3 h at 95 C.

(13) TABLE-US-00007 TABLE 4 Results of the fracture toughness measurement Irradiation method subsequent Irradiation method thermal curing 3 h at 95 C. Composition* K.sub.IC [MPam] Stdev K.sub.IC [MPam] Stdev VG3a 0.7 0.2 VG3b 0.8 0.2 VG3c 1.0 0.2 VG3d 0.9 0.2 Example 2 2.0 0.1 Example 2 1.9 0.2 Example 1 2.0 0.3 Example 1 2.3 0.3 Example 4 1.7 0.2 VG 1 1.4 0.2 VG 2 1.3 0.3 *Different polymerisation conditions of VG3a to VG3d, Example 4 with UV/Vis 1 60 seconds irradiated and subsequently thermally polymerised for approx. 3 h 95 C.

(14) The results of the fracture toughness measurement on the test specimens only radiation polymerised of the comparative examples with bis-GMA as a component in the polymer matrix show quite low values for the fracture toughness (VG3a, VG3b) which can no longer be significantly improved even in combination of a preceding irradiation with subsequent thermal curing for 3 hours at 98 C. (VG3c, VG3d).

(15) Even the examples with a TCD ester as component of the polymer matrix in examples VG1 and VG2 already show improved values compared to the matrix based on bis-GMA. Significantly better values of 1.9 and 2.3 MPa.Math.m.sup.1/2 for the fracture toughness are obtained with the composite materials according to the invention based on bis-(2,7-dioxa-3,8-dioxo-4-aza-decyl-9-ene) tetrahydrodicyclopentadiene as well as its isomers in the polymer matrix.