Dentistry – Prosthodontics – Denture base construction
Reexamination Certificate
1999-11-23
2001-06-12
Manahan, Todd E. (Department: 3732)
Dentistry
Prosthodontics
Denture base construction
Reexamination Certificate
active
06244869
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a frame for a removable dental prosthesis made of a composite material with laminated fiber reinforcement, pre-impregnated with a resin in the state prior to polymerization.
STATE OF THE TECHNIQUE
Known frames generally comprise metal plates obtained by long and costly casting processes. The presence of such a rigid metal plate inside the mouth is both unaesthetic and uncomfortable.
It has already been proposed to replace the metal plates of removable dental prostheses by lighter plates made of acrylic resin, in which reinforcing fibres are coated (document U.S. Pat. No. 4,894,012). Incorporating a network or a bundle of fibres is however not sufficient to obtain a significant mechanical strength of the acrylic resin plates. The fibres constitute a simple internal net enabling the fractured parts not to be completely detached after the plate has broken in the mouth.
OBJECT OF THE INVENTION
A first object of the invention is to achieve a frame for a removable dental prosthesis, which is particularly lightweight and has a high mechanical strength.
A second object of the invention also aims to propose a manufacturing process of a removable dental prosthesis frame which is particularly simple and quick to implement.
The frame according to the invention is composed:
of a base part comprising a layer of woven fabric of said composite material, which is arranged as a support shell in the form of an arch,
of an intermediate part extending along the top of the base part to form a beam having a good crushing strength, and forming the limits of the profile of the frame,
and of a surface part forming a cap totally covering the base part and intermediate part, the material of the cap being formed by a laminated fiber reinforcement material having an organic matrix of the same nature as that of the base part, the assembly made up of the three parts forming after shaping and polymerization a self-supporting profiled part exhibiting a good resistance to fracture.
According to a preferred embodiment, the intermediate part is formed by a bundle of long and continuous fibres extending along the profile of the beam and housed in a sheath acting as a cover. The sheath is formed by a woven assembly of fibres, which can be of the same nature as the fibres of the material of the other two base and surface parts.
According to one feature of the invention, the intermediate part is equipped with a shaping device designed to surround and clamp the sheath and bundle of fibres to define a predetermined transverse cross section.
According to another feature of the invention, the base of the sheath presents a conjugate shape to that of the top of the base part, and has a higher mechanical strength than that of the rest of the woven assembly of fibres of said sheath.
A first manufacturing process of the frame according to the invention is characterized by the following stages:
in a first stage the base part is placed on a laboratory model, said part comprising a laminated fiber reinforcement material pre-impregnated with resin reinforced with fibres and particles,
the base part is shaped under isostatic pressure by compression following placing of said laminated fiber reinforcement material on the laboratory model,
the resin of the shaped base part is polymerized to obtain a support shell in the form of an arch,
in a second stage the intermediate part is placed on the top of the arch of the base part,
and in a third stage said intermediate part is covered by the surface part shaped under isostatic pressure to form said cap after polymerization.
A second manufacturing process is characterized in that:
the intermediate part is first applied along the top edge of a laboratory model, without crushing the fibres of the sheath,
pre-polymerization of the intermediate part is performed to determine the profile of the frame,
the intermediate part is removed and the base part is placed on the model without prior shaping and without polymerization,
the pre-polymerized intermediate part is placed on the base part again, and is covered with the surface part,
the assembly is then shaped under isostatic pressure, followed by the complete polymerization stage of the frame.
According to another feature of the process, reservation elements passing transversely through the base part, the intermediate part, and the surface part are incorporated in the self-supporting profiled part before the shaping and polymerization phase, each reservation element being made of a material incompatible with the composite material of the profiled part to insure easy extraction thereof after shaping. Retaining parts are inserted in the confined cavities after the reservation elements have been extracted, each retaining part being formed by a tab having a protruding part for receipt of an artificial tooth.
Such a frame for a removable dental prosthesis can be securedly fixed to an attachment covering a root. The attachment comprises for this purpose
a male element formed by a cup filled with a photo curable composite material and fixed onto a root dental post or on a coronary reconstitution, said cup being made of a material transparent to electromagnetic rays and incompatible with the resin of the parts constituting the profiled part,
a female part composed of an envelope made of flexible material cooperating by engagement with the external face of the cup and secured to the self-supporting profiled part of the frame when the shaping operation is performed.
REFERENCES:
patent: 2418833 (1947-04-01), Harris et al.
patent: 4654006 (1987-03-01), Kusano et al.
patent: 4816194 (1989-03-01), Katayama et al.
patent: 4894012 (1990-01-01), Goldberg et al.
patent: 5676546 (1997-10-01), Heitmann et al.
patent: WO 90/11732 (1990-10-01), None
patent: WO 95/08300 (1995-03-01), None
patent: WO 96/15731 (1996-05-01), None
patent: WO 96/25911 (1996-08-01), None
patent: WO 98/19621 (1998-05-01), None
Billet Gilles
Clunet Coste Bruno
Collombin Andre
Maneuf Bernard
Manahan Todd #E.
Oliff & Berridg,e PLC
LandOfFree
Frame made of composite material for a removable dental... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Frame made of composite material for a removable dental..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frame made of composite material for a removable dental... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2453040