Hydrophilated dental impression compounds

Details Hydrophilated dental impression compounds Hydrophilated dental impression compounds

1996-05-16

1998-05-12

Merriam, Andrew E. C.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Processes of preparing a desired or intentional composition...

523120, 524377, 524588, 528 28, 528 29, 528 32, 433214, 556465, A61K 610, C07F 708

Patent

active

057505896

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to dental impression compounds hydrophilated by special additives.
With dental impression compounds based on addition-crosslinking or condensation-crosslinking silicones or else based on polyether silicones and polyethers, there is the problem that the drawing sharpness of the impression is not satisfactory because of poor flow behaviour of the paste as a result of inadequate hydrophilia. This problem is described e.g. in DE-A-38 38 587, page 2, lines 19-23 or in EP-A-0 480 238, page 2, lines 1-26.
Very varied additives which increase the hydrophilia of the impression compounds have been described in the literature for the solution of this problem. A survey of the state of the art is found for example in EP-A-0 480 238, page 2, lines 20-38. Polyether siloxanes, such as are described for example in international application WO 87/03001 or in EP-B-0 231 420, have proved to be particularly effective additives.
All the additives admittedly show an improvement in the hydrophilia of the impression compounds; however, they also display a series of problems, which are listed in the following:
Increased water absorption, with the consequence of dimensional instability caused by swelling (DE-A-43 06 997, page 2, lines 44 et seq.).
Development of gas bubbles in the case of silicone impression compounds (EP-A-0 480 238, page 2, lines 27-38, and DE-A-43 06 997, page 2, lines 44-56).
Poor stability (EP-B-0 231 420, page 5, lines 13-27).
Delay in setting (DE-A-43 06 997, page 2, lines 53 et seq.)
Loss of hydrophilia after disinfection (DE-A-43 06 997, page 2, lines 37 et seq; also Journal of Prosthodontics, Volume 3, No. 1, 1994, pages 31-34).
Poor stability of polyether siloxanes vis-a-vis hydrolysis (DE-C-43 20 920, page 2, lines 32-36). The long-term effect of the hydrophilation over the service life of a moulding compound is thus not guaranteed with certainty.
The polyether siloxanes mentioned above which are particularly suitable for the hydrophilation of dental impression compounds do however have a major drawback. The dental impression compounds hydrophilated with them are not adequately stable vis-a-vis disinfection baths. The impressions produced during treatment are disinfected at least twice in the usual way and there is thus an unwanted loss of hydrophilia.
It is the object of the invention to make available hydrophilated dental impression compounds from which dental impressions with improved resistance to disinfection baths can be produced.
This object is achieved by dental impression compounds which contain 0.1 to 10 wt.-%, relative to the total weight of the compound, of a polyether carbosilane as hydrophilation agent.
Particularly preferred as hydrophilation agents are polyether carbosilanes of the following general formula
Q stands for R.sub.3 Si-- ##STR1## where every R in the molecule can be the same or different and stands for an aliphatic C.sub.1 -C.sub.18, a cycloaliphatic C.sub.6 -C.sub.12 or an aromatic C.sub.6 -C.sub.12 hydrocarbon radical, which can optionally be substituted by halogen atoms,
R' is a C.sub.1 -C.sub.14 alkylene group,
R" is R in the case of a.noteq.0 or is R or R.sub.3 SiR' in the case of a=0, and a=0-2;
P stands for a C.sub.2 -C.sub.18 alkylene group, preferably a C.sub.2 -C.sub.14 alkylene group or A--R"', where A represents a C.sub.2 -C.sub.18 alkylene group and R"' a functional group from the following list:
--NHC(O)--, --NHC(O) (CH.sub.2).sub.n-1 --, --NHC(O)C(O)--,
--NHC(O) (CH.sub.2).sub.v C(O)--, --OC(O)--, --OC(O) (CH.sub.2).sub.n-1 --,
--OC(O)C(O)--, --OC(O) (CH.sub.2).sub.v C(O)--,
--OCH.sub.2 CH(OH)CH.sub.2 OC(O) (CH.sub.2).sub.n-1 --, --OCH.sub.2 CH(OH)CH.sub.2 OC(O) (CH.sub.2).sub.v C(O)
T is the same as H or stands for a C.sub.1 -C.sub.4 alkyl radical or a C.sub.1 -C.sub.4 acyl radical;
x stands for a number from 1 to 200, and
n stands for an average number from 1 to 6, preferably 1 to 4.
The polyether part can be a homopolymer, but can also be a statistical, alternating or block copolymer.
Polyether carbosilanes of the following gener

REFERENCES:
patent: 4248750 (1981-02-01), Murakami et al.
patent: 4565714 (1986-01-01), Koshar
patent: 4879339 (1989-11-01), Yoshino et al.
patent: 5051463 (1991-09-01), Yukimoto et al.
patent: 5138009 (1992-08-01), Inoue
patent: 5367001 (1994-11-01), Itoh et al.
patent: 5430166 (1995-07-01), Klein et al.

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