JP2001314423A - Method for preliminary heating of dental material and heating assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an assembly for improved hardening of a photo-setting dental repair composite material including unreacted monomers and fillers. SOLUTION: The photo-setting dental repair composite material is stored in a container and taken out of the container for clinical application into the mouth. The method for improving hardening of the photo-setting dental repair composite material including unreacted monomers and fillers in the mouth by exposing to light is to heat the container containing photo-setting dental repair composite material to elevate the temperature higher than room temperature before applying the photo-setting dental repair composite material in the mouth and exposing to light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method and a heating assembly for preheating dental material prior to clinical use, and more particularly to a method for preheating a dental material prior to clinical use. A method and a heating assembly for preheating dental material to an elevated temperature above ambient temperature.

[0002]

In accordance with the present invention, it has been found that many dental materials have enhanced properties by preheating immediately prior to clinical use. Examples of such dental materials include etching agents, bleaching compositions, dental cements,
Impression materials, and especially light-curable dental restorative materials, are included. All such dental materials are dispensed by dispensing devices such as syringes. At present, it is customary to package dental materials, especially dental restorative materials, as a unitary dose movable section (pharmacy device, hereinafter referred to as a "computer"). Drug dispensing equipment (di
The use of a spenser facilitates the handling of the dental material and the removal from the computer directly into the patient's mouth.

[0003] Photocurable dental restorative materials have become popular as an alternative to silver amalgam and have the advantage that they match the color of the teeth and, prior to hardening, match the irregularities and shape of the tooth holes. Photocurable dental materials are composite compositions of unreacted monomers and fillers that are formulated to polymerize by photochemistry upon exposure to light. In general, photocurable restorative materials are typically formulated as pastes for dental applications and polymerize by exposure to light in the range of 300-500 nanometers. The concentration of the filler in the composite material is adjusted for maximum strength and is typically 75-90% of the composition. The higher the filler concentration, the more viscous it becomes, making it difficult to administer, handle and polymerize the material. In addition, many dentists usually freeze the computer containing the light-curable dental restorative material before clinical use. The purpose of cooling and preserving is to suppress the spontaneous generation of free radicals in the material, thereby extending the useful life of the material. However,
The viscosity of the composition is also affected by the temperature, the lower the temperature, the more viscous the material. If not enough time is allowed to return the temperature of the frozen composition to room temperature, the properties of the photocurable material to flow and conform to the complex form of tooth cavity preparation are impaired.

[0004]

In accordance with the present invention, the degree of conversion, ie, the degree of conversion, is increased by preheating the photocurable composite material of the computer to a temperature above ambient immediately prior to clinical use. The percent conversion of unreacted monomer to polymer inside the cavity formation is substantially increased. Further, the pre-heating of the photocurable composite material of the Calcule substantially reduces the viscosity,
It is possible to load a higher amount of filler in the composite material, and the restoration material squeezed from the computer can be properly adapted to the walls of the cavitation and the complex shape of the cavitation.

[0005] The main effects of preheating the photocurable material of the computer prior to clinical use are as follows: (1) improved monomer conversion; (2) improved material hardness;
(3) Improvement of wear resistance, (4) improvement of color stability, and (5) improvement of strength.

[0006] Some or all similar effects are obtained by preheating dental materials other than photocurable restorative materials prior to clinical use. For example, heating a bleaching composition containing a peroxide bleach may be more activated at elevated temperatures. Thus, heating prior to clinical use improves the performance of many dental materials and, according to the present invention, reduces their use time.

[0007] The method of the present invention for enhancing curing upon exposure to light irradiation of a photocurable dental restorative composite material comprising unreacted monomers and fillers is useful for reducing exposure to light irradiation during clinical use. It broadly includes the step of pre-heating the photocurable dental restorative composite material to an elevated temperature above ambient.

[0008] The heating assembly of the present invention for heating dental material prior to clinical use includes a base, detachably attachable to the base to support one or more computing devices containing the dental restorative composite material. Including a mounted upper section, wherein the upper section is made of a conductive material;
The base is thermostat, a power connection for electrically connecting the thermostat to a power supply, and a high temperature uniform heating of the upper section preset by the thermostat for preheating the computer to a high temperature. Form a housing for the heating element.

A preferred heater assembly 10 of the present invention
1, 2, 3, 7 and 8, which include a base 12 having a removable top section 14 mounted on the base 12 and a removable cover 15. The heater assembly 10 can be of any suitable shape and size. In the embodiment of FIG. 1, the base 12 is cylindrical. The base 12 has a cavity 13 in which a thermostat 16 and a power connection 17 are mounted. The base 12 supports the removable upper section 14. The base 12 may be constructed from any suitable material, for example, plastic or metal. The power connection 17 extends from the cavity 13 in the base 12 to an outer surface 18 of the base 12 for electrically connecting the thermostat 16 to a suitable external power supply (not shown).
Although not shown, the heater assembly 10
May be operated by a rechargeable battery. The thermostat 16 may be connected in the circuit with a suitable visible light source (no indication) to provide a visual indication that the thermostat is operating and that the unit has reached temperature.

[0010] The thermostat 16 is electrically connected to a heating element 20 to form an electrical resistance heater that heats the upper section 14 to a controlled temperature. The heating element 20 is a conductive material in the form of a filament wire arranged in a serpentine or other shape or in the form of a flat conductor made of graphite, tungsten, copper or other suitable conductive material. To form a series of electrical paths. The heating element 20 includes:
A conductive plate 2 embedded in a plastic, ceramic or rubber composition and carrying said upper section 14;
1 to form a flat surface to be connected. The flat plate 21 is detachably fixed to the base 12 and provides a flat surface for uniformly heating the upper section 14 of the heater assembly 10. The thermostat 16 and the heating element 20 are commercially available as a single unit. The thermostat 16 controls the temperature of the heating element 20. Any conventional type of thermostat may be used for this application, preferably the heating element 2 described above.
A temperature of 0 is a suitable high temperature above ambient room temperature, preferably 100
Pre-adjust to ~ 140 ° F. The optimal temperature setting of the heating element 20 is about 130 ° for the photocurable dental material.
F. It may be higher for bleaching or other dental materials applied to the enamel. If the temperature is too high, the pulp will be damaged.

The removable upper section 14 of the heating assembly 10 is comprised of a conductive material such as aluminum, copper, brass or stainless steel and is disposed on a flat plate 21 which may be made of a similar conductive material. ing. The upper section 14 of the heating assembly 10 is provided with one or more grooves 22 to support a corresponding number of photocurable, resilient material computing 25. When heated, the upper section 14 acts as a heat sink by moving away from the base 12 to keep the computer at a relatively uniform temperature over time. In the embodiment of FIG. 1, four computing devices 25 are shown symmetrically arranged in grooves 22 which are arranged 90 ° apart from each other. The lid 15 is placed on a heating assembly to substantially enclose the computing device 25 within the enclosed space 27 and facilitate heating of the computing device 25. An insulating member 28, preferably an O-ring made of rubber or plastic, allows the upper section 14 to be removed from the base 12 to the dental tray adjacent to the patient at the elevated temperatures at which the compute 25 is heated. Surrounding.

The design of each individual computer 25 does not form part of the present invention. Computers of different designs are commercially available for normal use using separate dispensers. The computing device 25 is generally affixed to the distal end of the dispenser and has a profile at its distal end that includes an open tip 29 oriented at a suitable angle from the central axis of the computing device 25. The photocurable material is released into the oral cavity from the computer 25 as shown in FIGS. 3 and 7 by connecting each computer to a conventional dispensing syringe. Alternatively, a heating assembly may be used to heat the coupled computer syringe dispenser 31, as shown in FIG. Such a linked computing syringe dispenser 31 is currently commercially available. The upper section 14 of the heating assembly includes an annular channel 30 for receiving the tip 29 of the computing device 25. 7 and 8 show alternative arrangements to accommodate different compute / syringe designs.

According to the present invention, the reactive monomers in the photocurable material are converted to a substantially linear polymer over a wide temperature range from a refrigeration temperature of 20 ° F. to a high temperature of 150 ° F. Was found. This was demonstrated by the data illustrated in FIG. 4 using a commercially available photoactivated composite, designated as Herculite XRV, Shade A2, from Kerr / Sybron, Orange, CA. . A small amount of material is squeezed between the two muller strips at a selected preset temperature for a minimum of 30
Conditioned for minutes. A conventional dental photocurable unit was also placed in each temperature environment. In this environment,
The test piece was controlled at a controlled strength (500 mW / cm ² ).
For 60 seconds. After exposure, place the specimen in the dark for 24 hours.
Stored for hours. Thereafter, the degree of monomer conversion was determined using an infrared spectrometer (FTIR) and standard statistical analysis. FIG. 4 shows the relationship of monomer conversion to pre-cure temperature. 5 and 6 illustrate the effect of temperature on viscosity, including viscosity measured by changes in material thickness. Thus, a less viscous material has a smaller thickness. FIGS. 5 and 6 show that the increase in temperature of the photocurable material above ambient temperature, especially above 100 ° F., optimally at 130 ° F., before clinical use, unexpectedly improves curing. Represents the concept of

[Brief description of the drawings]

FIG. 1 is a perspective view of a heater assembly according to the present invention.

FIG. 2 is a cross-sectional view of the heater assembly of FIG.

FIG. 3 is a top view of the heater assembly of FIG. 1 with the cover removed.

FIG. 4 is a graph showing the relationship between pre-curing temperature and% conversion of monomer to polymer.

FIG. 5 is a graph illustrating the effect of various temperatures on the viscosity of a typical composite dental resin material before curing using the difference in viscosity indicated by measuring the average thickness change of the material at each temperature. is there.

FIG. 6 is a graph similar to FIG. 5 showing that the relationship between temperature and viscosity of the pre-cured dental material (measured by thickness change) is non-linear.

FIG. 7 illustrates another computing arrangement for the heater assembly of FIG.

FIG. 8 illustrates yet another computing arrangement using a small syringe with the heater assembly of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Heating assembly 12 ... Base 13 ... Cavity 14 ... Upper section 15 ... Lid 16 ... Thermostat 17 ... Power supply connection 18 ... Outer surface 20 ... Heating element 21 ... Conductive flat plate 22 ... Groove 25 ... Compute 27 ... Closed space 28 ... Insulation member 29… Tip 30… Annular channel

Claims (14)

[Claims] 1. A method comprising: storing a dental restorable composite material in a container; and removing the dental restorable composite material from the container into the oral cavity for clinical application.
A method for improving the hardening of a photocurable dental restorative composite material comprising unreacted monomer (s) and fillers in the oral cavity upon light irradiation, wherein the restorable composite material is removed from the container and applied to the oral cavity. Curing the dental restorative composite material by preheating the container containing the photocurable dental restorative composite material to a temperature higher than room temperature before irradiating with light during clinical use. How to improve. 2. The method of claim 1, wherein the container containing the dental restorative composite material contains a computer dispensed from a syringe. 3. The method according to claim 1, wherein the computing is about 100-140 °.
3. The method according to claim 2, wherein the preheating is performed to a temperature set at F. 4. The method of claim 3, wherein said computing is preheated to a temperature set at about 130 ° F. 5. The method of claim 6, wherein the one or more computing devices include a base having a top section made of a conductive material having a top section removably mounted on the base for supporting the computing device. A heating assembly for preheating stored dental material, the assembly including a thermostat, a power connection for electrically connecting the thermostat to a power source, and the upper portion for preheating the computing device to an elevated temperature. A heating assembly, further comprising a heating element for uniformly heating the section to a preset high temperature with a thermostat. 6. The heating assembly of claim 5, wherein said heating element is a conductive material in the form of a filamentary wire or a planar conductor connected to a thermostat to form an electrical resistance heater. 7. The heating assembly of claim 6, wherein said base further comprises a conductive material for connecting to said heating element and has a substantially horizontal surface on which an upper section of said heating element can be placed. 8. The heating assembly of claim 7, wherein said upper section comprises a body of conductive material that acts as a heat sink for the computer when detached from said base. 9. The method according to claim 9, wherein the upper section comprises aluminum,
9. The heating assembly according to claim 8, comprising a material selected from the group consisting of copper, brass and stainless steel. 10. The apparatus of claim 10, further comprising: a heat insulating member surrounding the upper section, wherein the heat insulating member removes the upper section from the base at an elevated temperature and enables the computer to be moved to the dental tray at an elevated temperature. Item 10. A heating assembly according to any one of Items 5 to 9. 11. The heating assembly according to claim 10, wherein said upper section has a plurality of slots, each holding a plurality of computers. 12. The heating assembly according to claim 10, further comprising a removable cover for said upper section. 13. A heating assembly as claimed in any of claims 5 to 12, further wherein each computer is introduced into a dispensing device as a single unit heated by the heating assembly. 14. The heating assembly according to claim 12, wherein said upper section has a plurality of slots for holding each dispensing unit for introducing a computer.