Plastic and nonmetallic article shaping or treating: processes – Dental shaping type – Tooth forming
Patent
1989-05-11
1992-05-05
Tentoni, Leo B.
Plastic and nonmetallic article shaping or treating: processes
Dental shaping type
Tooth forming
1562728, 1562733, 1562755, 1563071, 2504921, 264 22, 264250, 26433118, 26433121, 4332281, A61C 13087, B29C 3508, B29C 3940
Patent
active
051105136
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a process for producing an article made of resin by photopolymerization, with a low degree of shrinkage, and to applications of this process, in particular in the field of restoration of teeth and of dental and surgical prostheses.
BACKGROUND OF THE INVENTION
Composite plastic resins whose curing is ensured by photopolymerization are increasingly being employed as materials for filling, adhesive bonding, coating or impressing, and for other uses where their ease and quickness of use may be a decisive advantage.
In particular, in the field of restorative dentistry and of dental prostheses, such photopolymerizable resins are more and more frequently employed instead of materials of metallic type.
Similarly, in the field of bone surgery, these materials are increasingly employed for bone restoration or for the manufacture of prostheses.
These composite plastic resins generally consist of monomers or of a prepolymer which are mixed with a diluent to adjust its fluidity and with various additives promoting the photopolymerization. To this mixture, which forms the matrix of the composite resin, there is added a variable proportion, depending on the desired characteristics, of filler consisting of very fine grains or fibers of quartz, silica, and the like, intended to increase the mechanical properties (hardness, strength) of the composite resin.
In all these applications, and in particular when the polymerization must be performed in situ, the flexibility and the speediness of photopolymerization, i.e., polymerization under the effect of luminous radiation, constitute valuable advantages and make the practitioner's task easier.
The use of luminous sources of high photopolymerization performance, insofar as photopolymerization is concerned, particular of the argon laser, has made it possible to broaden the field of application and the practical possibilities of the use of this process.
However, the polymerization of composite resins is always accompanied by a volume shrinkage which results in major disadvantages and limits the performance of polymerizable resins in many applications.
This is so in the case of dental or bone restoration, where polymerization shrinkage can give rise to stresses which are capable of inducing pain in the patient or causing a certain deterioration of the prostheses, such as fissures, opening the way to bacterial infections.
In the case of other applications, and in particular in the case of the manufacture or of the assembly of highly precise industrial components, polymerization shrinkage makes it difficult to maintain accurate dimensions and gives rise to the appearance of fissures or of separations, in particular in the connecting regions between the components.
SUMMARY OF THE INVENTION
The object of the invention is a process for producing an article made of composite resin by photopolymerization, consisting in using at least one resin in an unpolymerized deformable state and then producing its polymerization under the effect of luminous radiation, with a very low polymerization shrinkage.
To this end:
the article is formed by juxtaposition of a main volume, equal to at least 80% of the total volume of the article, of a resin-based first photopolymerizable material and of a complementary volume of a resin-based second photopolymerizable material, and
the photopolymerization of the main volume of photopolymerizable material is produced in a first step and the photopolymerization of the complementary volume of photopolymerizable material is produced in a second step, the main volume and the complementary volume being maintained in contact in an assembly position.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, a description will now be given, by way of example, and with reference to the appended drawings, of an embodiment of the process according to the invention, in the case of the repair of a tooth by producing inside a dental cavity.
FIG. 1 is a sectional view of the dental cav
REFERENCES:
patent: 2491097 (1949-12-01), Feagin
patent: 3254411 (1966-06-01), Shelley
patent: 4234310 (1980-11-01), Leuthard
patent: 4267133 (1981-12-01), Kohmura et al.
patent: 4764118 (1988-08-01), Touati et al.
patent: 4822536 (1989-04-01), Voinis et al.
Framatome
Tentoni Leo B.
LandOfFree
Process for producing an article made of resin by photopolymeriz does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for producing an article made of resin by photopolymeriz, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing an article made of resin by photopolymeriz will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1410685