Fabrication of dental appliances
A dental appliance made of an olefin polymer is directly formed via rapid prototyping without the use of an intermediary physical mold. A polymer precursor solution includes one or more olefin-containing monomers and/or oligomers, an olefin polymerization catalyst, and a UV absorbing agent to limit penetration of the UV light through the polymer precursor solution. One or more reactions of the polymer precursor solution are modulated in response to UV light, and the polymer precursor solution may further include an inhibitor (quenching agent) configured to modulate those reactions. The polymer precursor solution can be deposited using UV-cured stereolithographic or 3D printing methods to form appliances exhibiting improved elongation at break characteristics and suitable stress resistance.
1. A method of fabricating an orthodontic aligner, the method comprising:
providing an olefin polymer precursor solution to a stereolithography or digital light processing machine, the olefin polymer precursor solution comprising a monomer or oligomer, a catalyst, an olefin-containing quenching agent, and a separate UV absorbing agent, one or more reactions of the polymer precursor solution being modulated in response to UV light; and
fabricating the orthodontic aligner using the stereolithography or digital light processing machine according to an appliance model such that stereolithography or digital light processing of the olefin polymer precursor solution produces the orthodontic aligner comprising an olefin polymer having a stress resistance of at least about 5,000 psi and an elongation at break of about 6% to about 200%.
2. The method of claim 1 , wherein the olefin polymer precursor solution is configured to form an olefin polymer via ring opening metathesis polymerization (ROMP).
3. The method of claim 2 , wherein the monomer or oligomer comprises 1,5-cyclooctadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, or a mixture thereof.