Electric heating – Heating devices – Combined with container – enclosure – or support for material...
Reexamination Certificate
2000-08-25
2001-11-20
Pelham, Joseph (Department: 3742)
Electric heating
Heating devices
Combined with container, enclosure, or support for material...
C219S386000, C433S032000, C433S226000, C433S228100
Reexamination Certificate
active
06320162
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a method and heating assembly for pre-heating dental material(s) prior to clinical usage and more particularly to a method and device for pre-heating compule(s) of dental material to an elevated temperature, above ambient, prior to clinical usage.
BACKGROUND OF INVENTION
In accordance with the present invention it has been discovered that many dental materials have properties which can be enhanced by being preheated just prior to clinical usage. Examples of such dental materials include etching agents, bleaching compositions, dental cements, impression materials and more particularly photocurable dental restorative materials. All such dental materials can be dispensed through a dispensing device such as a syringe. Presently, it has become conventional to package dental material(s) particularly dental restorative materials in unit dosage within a removable section hereafter called a “compule” of the dispensing device. The use of a dispenser facilitates the handling and discharge of the dental material(s) from the compule directly into the patient's mouth.
Photocurable dental restorative materials have become popular as a replacement for silver amalgams and have the advantage of matching the tooth color and being adjustable in the dental cavity for contour as well as shape before curing. Photocurable dental materials are composite compositions of unreactive monomer(s) and filler formulated to be polymerized by photochemical action upon exposure to light. In general photocurable restorative materials are typically formulated for dental usage as a paste and will polymerize upon the application of light in the 300-500 nanometer range. The concentration of filler in the composite is adjusted as high as possible to maximize strength, typically between 75-90% of the composition. The higher the filler concentration the more viscous and the more difficult the material is to dispense, handle and polymerize. Moreover, it is conventional for many dentists to refrigerate compules containing the photocurable dental restorative material prior to clinical use. The purpose of cold storage is to slow down the natural generation of free radicals within the material and thereby extend the useful life of the material. However, the viscosity of the composite is also subject to temperature and the colder the temperature the more viscous the material becomes. The ability of the photocurable material to flow and adapt to the intricacies of a dental cavity preparation will be compromised if sufficient time is not given to restore the temperature of the refrigerated composite back to room temperature.
SUMMARY OF THE INVENTION
It has been discovered in accordance with the present invention that when compules of photocurable composite materials are pre-heated to an elevated temperature above ambient immediately prior to clinical usage the degree of conversion i.e., the percentage of unreacted monomer converted to polymer within the cavity preparation is substantially increased. In addition, by pre-heating the compules of photocurable composite materials its viscosity is substantially reduced permitting yet higher filler loading(s) in the composite material and enabling the restorative material expressed from the compule to adapt better to the walls of the cavity preparation and to the intricacies of the cavity preparation.
The principle advantages of preheating compules of photocurable material(s) prior to clinical usage are as follows:
(1) Improved monomer conversion,
(2) Improved material hardness,
(3) Improved wear resistance,
(4) Improved color stability, and
(5) Improved strength.
Some or all of the same advantages apply when preheating dental material other than photocurable restorative material(s) prior to clinical usage. For example heating a bleaching composition containing a peroxide bleaching agent will be more active at higher temperatures. Thus the performance of many dental material(s) heated prior to clinical usage will be improved and their application time decreased in accordance with the present invention.
The method of the present invention for enhancing the cure of photocurable dental restorative composite materials containing unreactive monomer(s) and filler upon exposure to light radiation broadly comprises the step of preheating the photocurable dental restorative composite(s) to an elevated temperature above ambient prior to said exposure to light radiation during clinical usage.
The heating assembly of the present invention for heating dental materials prior to clinical usage comprises a base, an upper section removably mounted on the base for supporting one or more compules containing photocurable dental restorative composite material(s), with the upper section being composed of a conductive material and with the base forming a housing for a thermostat, a power connection for electrically connecting the thermostat to a source of power and a heating element for uniformity heating said upper section to an elevated temperature preset by said thermostat for preheating said compules to said elevated temperature.
REFERENCES:
patent: 2269874 (1942-01-01), Henschel
patent: 3902043 (1975-08-01), Rogan
patent: 4092138 (1978-05-01), Beitner
patent: 4287408 (1981-09-01), Wilson
patent: 4361528 (1982-11-01), Ginsburg et al.
patent: 4924070 (1990-05-01), Friedman
patent: 5718586 (1998-02-01), Sharp et al.
patent: 5814682 (1998-09-01), Rusin
patent: 5856373 (1999-01-01), Kaisaki
patent: 5925715 (1999-07-01), Mitra
patent: 6127451 (2000-10-01), Qian
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