Dental composition
The present invention relates to a dental composition comprising a radically polymerizable compound, a redox initiator system comprising one or more clathrate compounds comprising a host molecule and one or more guest molecules, wherein the host molecule is selected from cyclodextrines, crown ethers, cucurbituriles and calixarenes and the one or more guest molecules are reducing agents, and an oxidizing agent. Furthermore, the present invention relates to a use of the redox initiator system in a dental composition.
1. A dental composition comprising
(i) a radically polymerizable compound; and
(ii) a redox initiator system comprising
(a) one or more clathrate compounds comprising
(a1) a host molecule and
(a2) one or more guest molecules,
wherein the host molecule is selected from crown ethers, cucurbiturils, and calixarenes, and the one or more guest molecules are reducing agents; and
(b) an oxidizing agent.
2. The dental composition according to claim 1 , wherein the reducing agent is an aromatic tertiary amine, a phosphine or a borane.
3. The dental composition according to claim 1 , wherein the reducing agent is a tertiary amine of the following formula (I):
wherein
R 1 and R 2 which may be the same or different, independently represent straight chain, branched or cyclic C 1-8 alkyl group, or R 1 and R 2 form together with the nitrogen atom to which they are bonded a 3-8 membered saturated heterocyclic ring; and
R 3 represents an organic group.
4. The dental composition according to claim 3 , wherein the reducing agent is 4-tert.-butyl-N,N-dimethylaniline.
5. The dental composition according to claim 1 , wherein the molar ratio of the guest molecules: the host molecules is in the range of from 1:0.5 to 1:3.
6. The dental composition according to claim 1 , wherein the oxidizing agent is a peroxide which is selected from cumyl hydroperoxide, tert-butyl peroxybenzoate, tert-butylperoxy (2-ethylhexyl)carbonate, tert-butylhydroperoxide, di(tert-butyl)peroxide, tert-butylperoxy-3,5,5-trimethyl-hexanoate, and potassium peroxydisulfate.
7. The dental composition according to claim 1 , which is a resin modified dental cement composition.
8. The dental composition according to claim 1 , which is a two-pack dental composition.
9. The dental composition according to claim 1 , wherein the redox initiator system including the one or more clathrate compounds and the oxidizing agent are stored as a mixture in a single pack.
10. A dental composition comprising
(i) a radically polymerizable compound; and
(ii) a redox initiator system comprising
(a) one or more clathrate compounds comprising
(a1) a host molecule and
(a2) one or more guest molecules,
wherein the host molecule is selected from cyclodextrins, crown ethers, cucurbiturils, and calixarenes, and the one or more guest molecules are borane reducing agents; and
(b) an oxidizing agent.
11. The dental composition of claim 10 , wherein the borane has a structure of the following formula (II):
R 12 R 13 R 14 B (II)
wherein
R 12 , R 13 , and R 14 which may be the same or different, independently represent a C 1-8 alkyl group or a C 4-10 aryl or heteroaryl group.