WO1999066856B1

WO1999066856B1 - Denture system

Info

Publication number: WO1999066856B1
Application number: PCT/US1999/014088
Authority: WO
Inventors: Richard Jacobs; Don Porteous; Eckart Mathias; Juan Cervantes
Original assignee: Cadco Dental Products Inc; Richard Jacobs; Don Porteous; Eckart Mathias; Juan Cervantes
Priority date: 1998-06-23
Filing date: 1999-06-22
Publication date: 2000-03-02
Also published as: WO1999066856A1; AU4707599A

Abstract

Denture product and forming system for denture products comprising tooth structure and a supporting base, including: a fluid, two-component thermosetting resin supply (70) having a mixer for mixing a resin reactive mixture from the components and an injection outlet (84) from the mixer; a denture mold (28) comprising a closed cavity (68) having an inlet for receiving delivery of the resin reactive mixture from the supply under injection pressure and at a predetermined cavity filling flow rate; and spaced from the inlet a vent (86, 88) adapted for venting gases from the cavity while blocking resin reactive mixture from emptying from the cavity at greater than a predetermined cavity emptying flow rate which is less than the cavity filling flow rate, so that the resin reactive mixture overfills the cavity and self-pressurizes to a pressure sufficient to block any incorporated gases in the resin reactive mixture from forming voids or bubbles during curing.

Claims

- 42 -

AMENDED CLAIMS

[received by the International Bureau on 16 December 1999 (16.12.99); original laims 1, 7, 13 and 44 amended; remaining claims unchanged (7 pages)]

1. System for forming dentures comprising tooth structure and a supporting base including: a fluid, two-component thermosetting urethane resin supply generally closed to ambient air and prcssurizable to an injection pressure, said resin supply having a mixer ibr mixing a resin reactive mixture from said components and reacting to a resin having a first increased viscosity preventing surface porosity in said reaction mixture from moisture side reactions and an injection outlet from said mixer; a denture mold comprising a closed cavity in which said tooth structure is supported in its intended position in the denture with its roots exposed into th cavity, said mold cavity having an inlet for receiving delivery of said first increased viscosity resin reactive mixture from said supply under said injection pressure and at a predetermined cavity filling flow rate for cure to a second increased higher viscosity resin within said cavity in denture-forming relation; said second increased higher viscosity resin reactive mixture carrying with it gases present in said cavity, and spaced from said inlet a vent adapted for venting said carried gases from said cavity while blocking said second increased higher viscosity resin reactive mixture from emptying from said cavity at greater than a predetermined cavity emptying flow rate, whereby said rcsin reactive mixture inflow and increase to said second increased higher viscosity .self-prcssurizcs said rcsin reactive mixture sufficiently lo block any carried gases in said rcsin reactive mixture from forming voids or bubbles therein during cure. thereof visible in a denture comprising the. resin reaction product of said resin reactive mixture cured to a solid in the. shape of said mold cavity.

2, The system according to claim I, in which said cavity comprises a wall in which said inlet and vent are formed, a tooth support structure within and surrounded by said cavity wall, said tooth support structure tending to be moisture containing, and including also coating said tooth support structure with a moisture barrier coating in advance of injection of said resin reactive mixture thereinto to block exposure of said resin reactive mixture to said tooth support structure moisture, 3. The s-ystem according to claim 2, including also selecting a thcrmoselting resin as said moisture barrier coating.

4. Tiie system according to claim 3, including also selecting a two-component thermosetting urethane resin as said moisture barrier coating, mixing sπid components in reactive proportions, and applying the :nixturc to said tooth support structure in moisture barrier coaling forming relation.

5. The system according to claim 3, including also selecting a two-component vinyl silane rcsin as said moisture barrier coating, mixing said components in reactive n proportions, and applying the mixture to said tooth support structure in moisture barrier coating forming relation.

6. The system according lo claim 1 , in which said resin supply injection outlet comprises a no /.lc, said mold cavity inlet receiving said resin reactive mixture from said supply free of entrained ambient air in said resin reactive mixture. 0 7. The system according to claim 1, in which said rcsin supply mixer comprises a static mixer adapted to mix said resin components into said resin reactive mixture in advance of said injection outlet from said mixer, said injection outlet comprising a nozzle iπsertabte into said mold cavity inlet for delivery of said resin reactive mixture at said first increased viscosity into said mold cavity free of entrained ambient air. 5 8. The system according to claim 1, in which said supply includes first and second chambers containing respectively first and second side precursor components of a thermosetting rcsin, and a source of pressure for each of said chambers including a movable member adapted to drive each chamber- contained component from its chambers to said mixer. 0 9. The system according to claim Α, in which said source of chamber pressure includes a pressurized fluid supply selectively coupled to said chamber movable members for moving said members in precursor component driving relation from said chambers.

10. The system according to claim 8, in which said chambers comprise cylinders having movable pistons therein as said movable members, and a supply of pressure, to said 5 pistons for expressing said precursor components from said cylinders, each of said cylinders having an outlet normally closed against ambient air, said outlets being openablc for delivery of said precursor components, said precursor components f rther comprising a finely divided mineral filler in a viscosity increasing amount sufficient to block retreat of said precursor components farther into their cylinders upon opening said outlets in reaction to ambient air 0 pressure causing the creation of bubbles in either precursor resin.

11. The system according to claim 10, in which said mineral filler comprises fumed silicu. 2. The system according to claim 1 1 , in which said fumed silica is present in an amount between about 0, 1 and 10% by weight of the precursor component in said cylinder. 5 13. Low pressure system for forming dentures comprising tooth structure and a supporting base, including: - 44 -

a fluid, two-component urethane resin supply generally closed lo ambient air and presstu isable lo an injection pressure, said resin supply having a mixer for mixing a resin reactive mixture from said components and reacting to a resin having a first increased viscosity preventing surface porosity in said reaction mixture from moisture side reactions and an

5 injection outlet from said mixer; a denture mold comprising a closed cavity in which said looth structure is supported in its intended position in the denture with its roots exposed into the cavity, said mold cavity having an inlel for receiving delivery of said first increased viscosity resm reactive mixture from said supply under said injection pressure and at a predetermined cavity filling flow rate for cure to a second increased higher viscosity resin within aid cavity in denture-forming relation; said second increased higher viscosity resin reactive mixture having a fluidity to sweep away from the cavity surfaces and the tooth roots and carry with it gases present in said cavity, and spaced from said inlet a vent adapted for venting said carried gases from said cavity 5 while blocking said second increased liiglier viscosity resin reactive mixture from emptying from said cavity at greater than a predetermined cavity emptying flow rate, whereby said resin reactive mixture inflow and increase to said second increased higher viscosity self-pressurizes said resin reactive mixture to a pressure sufficient to block any carried gases in said resin reactive mixture from forming voids or bubbles therein during O cure thereof visible in a denture comprising the resin reaction product of said resin reactive mixture cured to a solid m the shape of said mold cavity.

14. The system according to claim 13, in which said urethane resin is the reaction product of a first precursor component comprising an isocyanato reagent, a second precursor component resin moiety comprising a polycther, polyester, urea, urethane, castor oil, oxazole, f_> oxazolidone, oxazolidinone, amide, imide, or imine mυicly and a chain extender, said resin moiety and said chain extender each having separately active hydrogen, hydroxyl, amine, or amide functionality

15. The system according to claim 14, in which said second precursor component resin moiety has a active hydrogen or hydroxyl functionality and a molecular weight above 0 about 1000.

16. The system according to claim 14, in which said second precursor component resin moiety has a molecular weight above about 5000.

17. The system according to claim 14, in which said chain extender has a molecular weight below about 500, and a functionality of at least i. - 45 -

18, The system according to claim 17, in which said chain extender has a functionality of at least 4.

19, Ihe system according to claim 18, in which said chain extender comprises a lertiary amine having active hydrogen or hydroxyl functionality.

20, The system according to claim 19 in which said chain extender comprises a lertiary amine having the formula

R R - C - R

R R R R

R C C N

R R

C C R

R R in which at least one R=R1 and each remaining R is RI or R2, and: in which:

Rl= OH;

SH;

N(CH2CH20H)2; -N(CΪT2CΪT3CII201D2. -N(C112C1ICH30H)2;

R2= -H;

Me; -Alkyl; -OAlk; -OMe; -Halogen;

-Λryl;

-Λroyi and cyclics of the above

21. The system according to claim 20 in which said tertiary amine comprises ethylene diamine tetrapropoxylate. 22. The system according to claim 18, in which said chain extender comprises an alkylene oxide or ether adduet of a highly functional molecule.

23. The system according to claim 22, in which said highly liinclional molecule has a hydroxyl functionality between 4 and 12.

24 The system according tu claim 23, in which said highly functional molecule comprises penlaerylhritol, sugar, starch or cellulose molecules, - 46 -

25. The system according to claim 24, in which said highly functional molecule comprises pentaerythritol,

26. The system according to claim 25, in which said pentøcrylhritol molecule is adducted with ethylene and/ or propylene oxide. 27. The system according to claim 26, in which said adducted pentaerythritol molecule has a molecular weight of about 450.

28. The system according to claim 24, in which said highly functional molecule comprises a sucrose, fructose, or sorbitol molecule.

29. The system according to claim 1 , in which said isocyanato reagent comprises an aliphatic isocyanate.

30. The system according to claim 29, in which said aliphatic isocyanate comprises methylenedicyclohexatie -4, 4'~dϋsocyanate 1. The system according lo claim 14, in which said first isocyanato reagent comprises an aromatic isocyanate. 32. The system according to claim 31, in which said aromatic isocyanate comprises diphenylmethane diisocyanate.

33. The system according to claim 32, in wliich said resin moiety comprises a polyether, polyester, urea, urethane, castor oil, oxazole, oxazolidone, oxazolidinone, amide, imidc, or nninc moiety having active hydrogen, hydroxyl, amine, or amide functionality and a molecular weight above about 5000.

34. The system according to claim 33, in which said chain extender comprises pentaerythritol molecule adducted with ethylene and/ or propylene oxide and having a molecular weight below about 500.

35. The system according to claim 33, in which said resin moiety comprises a primary or secondary hydroxyl functional polyelher polyol having an equivalent weight from out 20 to about 10,000 daltons- and a functionality of about 1 to about 20.

3G. The system according to claim 35, in which said polyether polyol comprises a poly oxy-propylene oxide ether polyol.

37. The system according to claim 35, in which aid polyether polyol has a f nctionality of irom about 1 to about 3,

3<S. The system according to claim 35, in which said chain extender comprises ethylene diamine tetrapropoxylate.

3°. The system according to claim 1 , including also maintaining said supply resin components and said resin reactive mixture free of surface contact with ambient air before and during delivery thereof to said mold cavity. - 47

40. The denture forming system according to claim 1, including also progressively increasing the viscosity of said resin reactive mixture in said mold cavity over a time period TI, and driving air from said mold cavity by tilling said mold cavity with increasing amounts of said increasing viscosity rcsin reactive mixture. 41. Ihe system according to claim I, including also maintaining said resin reactive mixture flowablc over a time period T2, f^'illiiig said mold cavity with said reactive mixture over a period T3, and maintaining said time period T2 greater than said lime period T3.

42 The system according to claim 41 , including also progressively increasing the viscosity of said resin reactive mixture over time period T2, and driving air from said mold cavity by filling said mold cavity with increasing amounts of said inc. asing viscosity resm reactive mixture.

43. The system according to claim 1, in which said resin reaction mixture tends to shrink in siκe during cure, and including also overfilling said cavity with pressurized resin reactive mixture sufficiently to compensate for said size shrinkage and completely fill aid cavity in the cured condition of said resin.

ΛΛ. The system according to claim 1 in which the resin reactive mixture al aid second increased higher viscosity is pressurized within said mold cavity to a pressure of from about 1 to about 40 psi above ambient atmospheric pressure, said pressure and resin reactive mixture viscosity being sufficient to block any incorporated gases in said mixture from forming voids or bubbles visible in a denture formed therefrom.

45. Denture forming apparatus comprising a mold cavity, artificial teeth, a support supporting said artificial teeth within said cavity, and a resin supply supplying a liquid reactive rcsin mixture under injection pressure, said mold cavity having a resm reaction mixture injection inlet and spaced therefrom a vent, said vent being flow- estricted relative to said inlet, whereby said resin reactive mixture is pres.surized within said mold cavity.

4( . Denture forming apparatus according to claim 45, including also a mixer and tip for mixing said resin reactive mixture and delivering said mixture to said moid cavity inlet, said tip being received within said mold cavity in sealing relation against air incursion into said mold cavity with said mixture.

47. Denture forming apparatus according to claim 45, including also a pressure source pressuring said mixture for delivery into said mold cavity.

48, Denture forming apparatus according to claim 47, in which said pressure source comprises a pneumatic pressure source, 49. A denture formed by the system of claim 1. - 48 -

50. A visible void- and bubble free denture comprising one or more teeth arid a resin support, said resin support comprising a urethane resin reaction product of an isocyanato reagent, a resin moiety and a chain extender formed under abov atmospheric pressure conditions in a substantially closed mold cavity against a moisture-barπer-coated stone with said teeth supported therein.

51. A visible void- and bubble-free denture comprising one or more teeth and a resin support, said resin support comprising a urethane resin reaction product of an isocyanato reagent comprising diphcnylwethane diisocyanate, a resin moiety comprising a poly oxy-propylene oxide ether polyol and a chain extender comprising a tertiary amine or a pentaerythritol addυct with an alkylene oxide, formed under above atmospheric pressure conditions in a substantially closed mold cavity against a moisture-barrier-coated stone with said teeth embedded therein.

52. Λ method of restorative dentistry including taking an impression of a patient's gums, forming a visible void- and bubble free denture comprising one or more teeth and a resm support, said rcsin support comprising a urethane resin reaction product of an isocyanato reagent comprising diphcnylmethane diisocyanate, a resin moiety comprising a poly oxy-propylene oxide ether polyol, and a chain extender comprising tertiary amine or a pentaerythritol adduct with an alkylene oxide formed under above atmospheric pressure conditions in a substantially closed mold cavity against a moisture- barrier-coated stone with said teeth embedded therein, and fitting said patient with said denture.