Composite material with low polymerisation shrinkage stress

Abstract

For composite materials having a total filler content of 80 to 95% by weight , containing A) 0.5 to 10% by weight of non-agglomerated nanofillers having particle sizes of 1 to 50 nm in the filler component, B) at least 60% by weight of a filler mixture of 50 to 90% coarse-partic le and 10 to 50% fine-particle dental glass in the filler component, having a size ratio, relative to the average particle size (d50 value), of coarse to fine particles of > 1:4 to 1:30, C) as monomer component, a monomer mixture of i. 60 to 80% bis-GMA or TCD-di-HEMA or TCD-di-HEA, ii. 10 to 18% UDMA, iii. Residual TEDMA and / or multifunctional crosslinkers, D) up to 1 % photoinitiator(s); and E) optionally, at least one additional dental glass in the filler compone nt having a different particle size than the coarse- and fine-particle dental glass, the polymerization shrinkage may be reduced to < 1.6% by volume, and the shrinkage force may be reduced to < 3.5 MPa.

Description

technical field [0001] The present invention relates to composite materials with slight shrinkage forces. Background technique [0002] Light-hardening materials based on acrylate- / methacrylate undergo a violent polymerization reaction, because the molecular distance decreases during the polymerization reaction, resulting in an increase in density and thus causing volume shrinkage. By adding inorganic fillers, such as dental glass or exothermic silicic acid, this shrinkage can be significantly reduced, because the proportion of monomers per unit volume is reduced, and fillers do not shrink during polymerization. [0003] In dental medical applications, volume shrinkage has great clinical significance, because the shrinkage of the material will generate tension on the cavity wall of the diseased tooth. In extreme cases, when the upper limit is exceeded, this pulling force can cause the material to detach from the cavity wall. Bacteria are able to invade the border gap thus ...

AI Technical Summary

Problems solved by technology

However, the more layers of fillings that must be individually hardened, the longer it will take for the dentist to perform the operation

Images